Extra Research
Welcome to the Extra Research Page, where I'll keep all the extra research I do.
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Anal Adenocarcinomas (Anal Gland Cancer) in Dogs
Cancer of the anal gland/sac cancer (called an adenocarcinoma) may not be the most common, but its presence is surely something to take note of. Due to the type of disease, which is a cancer, it is typically malignant and can spread quickly into other areas of the animal's body. The most common sign of this cancer is a rectal mass or tumor, which is often small in nature. In addition to the visible signs of a tumor, animals who are suffering from the disease may be constipated, have difficulty defecating (obstipation), a reluctance to eat, or polydipsia (excessive thirst). It can also be found in the lymph nodes. While this disease is common in dogs (no particular breed though), it is not common in cats. The disease is often associated with a hormone imbalance (in the parathyroid that regulates calcium levels), as it is often found in the anal area. It is also linked with hypercalcemia (too much calcium in the bones that leads to weakness and certain organ failure) in the animal's body. To test the nature of the tumor, a fine needle is inserted into the cancerous anal mass and the cells are examined to rule out any other possible conditions. It can be challenging to determine whether the mass is malignant or not, so the needle biopsy is a useful diagnostic test. In some cases an incision and a full biopsy are needed to properly diagnose the mass. Some veterinarians will also use imaging to look at the mass, such as X-rays or ultrasounds.
The proper treatment is to surgically remove the tumor, which can prolong an animal's life. However, the tumor's removal is not a cure. Radiation is also used to help with locally recurring tumors. After the tumor is removed, the animal should continue to be watched through physical examinations, X-rays, ultrasounds, and blood work. Calcium and kidney tests also work in monitoring the disease and its potential recurrence. The overall prognosis for the disease is poor, although surgery can substantially improve the opportunity for recovery. Sadly though, due to its nature, there is currently no way to prevent the disease.
Cancer of the anal gland/sac cancer (called an adenocarcinoma) may not be the most common, but its presence is surely something to take note of. Due to the type of disease, which is a cancer, it is typically malignant and can spread quickly into other areas of the animal's body. The most common sign of this cancer is a rectal mass or tumor, which is often small in nature. In addition to the visible signs of a tumor, animals who are suffering from the disease may be constipated, have difficulty defecating (obstipation), a reluctance to eat, or polydipsia (excessive thirst). It can also be found in the lymph nodes. While this disease is common in dogs (no particular breed though), it is not common in cats. The disease is often associated with a hormone imbalance (in the parathyroid that regulates calcium levels), as it is often found in the anal area. It is also linked with hypercalcemia (too much calcium in the bones that leads to weakness and certain organ failure) in the animal's body. To test the nature of the tumor, a fine needle is inserted into the cancerous anal mass and the cells are examined to rule out any other possible conditions. It can be challenging to determine whether the mass is malignant or not, so the needle biopsy is a useful diagnostic test. In some cases an incision and a full biopsy are needed to properly diagnose the mass. Some veterinarians will also use imaging to look at the mass, such as X-rays or ultrasounds.
The proper treatment is to surgically remove the tumor, which can prolong an animal's life. However, the tumor's removal is not a cure. Radiation is also used to help with locally recurring tumors. After the tumor is removed, the animal should continue to be watched through physical examinations, X-rays, ultrasounds, and blood work. Calcium and kidney tests also work in monitoring the disease and its potential recurrence. The overall prognosis for the disease is poor, although surgery can substantially improve the opportunity for recovery. Sadly though, due to its nature, there is currently no way to prevent the disease.
Bowen's Disease (Multicentric Squamous Cell Carcinomas) in Dogs
Squamous cell carcinoma (SCC) is a tumor of skin cells. Because this type of cancer arises from squamous cells, tumors can develop anywhere that these cells are present (such as the nail bed, paw pads, abdomen, back, ears, or the nose). Squamous cell carcinomas usually appear as a single, solitary lesion in one location, but there is a kind of SCC called multicentric squamous cell carcinoma (also known as Bowen’s disease) that presents as many (two or more) lesions in multiple locations on the body. Multicentric SCC is very rare in dogs.
As with SCC in humans, exposure to ultraviolet rays/sunlight has been attributed to the development of these tumors. Certain breeds are known to have an increased incidence of SCC, including Scottish Terriers, Pekingese, Boxer Dogs, Poodles, and Norwegian Elkhounds. SCC of the skin is also more common in dogs that are sparsely haired and have light-colored hair and skin (e.g. Dalmatians, Beagles, Whippets, and white Bull Terriers). This makes sense, because the dog I saw who had this issue was a white bulldog with only a few patches of fur.
Typically, these lesions are found in light-skinned areas and can be highly variable in their appearance. It may look like a small area of irritated, red, or ulcerated skin. Alternatively, there could be plaques or crusts that develop over the region. SCC lesions of the toe or nail bed tend to be red, irritated, bothersome, and ulcerated. Dogs may even lose nails on the affected toes.
A fine needle aspiration or a biopsy may be used to diagnose this issue. Affected animals should definitely limit their time spent in the sun and can use certain salves to soothe any dryness or itchiness.
As with SCC in humans, exposure to ultraviolet rays/sunlight has been attributed to the development of these tumors. Certain breeds are known to have an increased incidence of SCC, including Scottish Terriers, Pekingese, Boxer Dogs, Poodles, and Norwegian Elkhounds. SCC of the skin is also more common in dogs that are sparsely haired and have light-colored hair and skin (e.g. Dalmatians, Beagles, Whippets, and white Bull Terriers). This makes sense, because the dog I saw who had this issue was a white bulldog with only a few patches of fur.
Typically, these lesions are found in light-skinned areas and can be highly variable in their appearance. It may look like a small area of irritated, red, or ulcerated skin. Alternatively, there could be plaques or crusts that develop over the region. SCC lesions of the toe or nail bed tend to be red, irritated, bothersome, and ulcerated. Dogs may even lose nails on the affected toes.
A fine needle aspiration or a biopsy may be used to diagnose this issue. Affected animals should definitely limit their time spent in the sun and can use certain salves to soothe any dryness or itchiness.
Common Cancers in Cats
Right up next to heart disease kidney failure, and certain diseases, cancers are one of the leading causes of death in cats. Though the cancer rate in cats is about half the rate in dogs, it is still one of the highest reasons for death in cats, especially in senior cats. Because the cancer rate for cats is about half of what it is for dogs, I will only be listing the 5 most common types of cancer, which will be elaborated upon in other posts.
1. FeLV (Feline Leukemia Virus)
2. Fibrosarcoma
3. Lymphomas
4. Mammary Cancer
5. Squamous Cell Carcinoma (skin cancer)
Right up next to heart disease kidney failure, and certain diseases, cancers are one of the leading causes of death in cats. Though the cancer rate in cats is about half the rate in dogs, it is still one of the highest reasons for death in cats, especially in senior cats. Because the cancer rate for cats is about half of what it is for dogs, I will only be listing the 5 most common types of cancer, which will be elaborated upon in other posts.
1. FeLV (Feline Leukemia Virus)
2. Fibrosarcoma
3. Lymphomas
4. Mammary Cancer
5. Squamous Cell Carcinoma (skin cancer)
Common Cancers in Dogs
Cancer, a nonstop division of somatic (body) cells into surrounding tissues, is one of the most common ailments in both humans and dogs. In fact, this disease is so common that the University of Georgia College of Veterinary Medicine has discovered that cancer was the most common cause of death in older dogs. Through research, I have found there are 10 main types of cancer in dogs. These cancer types, which are listed below, will be further explored in other research.
1. Anal Gland Adenocarcinomas
2. Hemangiosarcomas
3. Lipomas
4. Lymphomas
5. Mammary Gland Carcinoma
6. Oral Melanomas
7. Osteosarcomas
8. Primary Lung Tumors
9. Thyroid Carcinomas
10. Tumors from Mast Cells
Feline Leukemia Virus
Feline leukemia virus (FeLV) is the second leading cause of death in cats, killing 85% of continually infected felines within three years of their diagnosis. This virus commonly causes anemia (low red blood cell count) or lymphoma (cancer in lymph nodes), but because it is highly immunosuppressive, it can expose cats to other deadly diseases. Feline leukemia is a disease that only affects cats and is passed from one cat to another through mainly saliva and blood. Grooming and fighting seem to be the common ways for the infection to spread, however kittens can contract the disease through an infected mother’s milk. The disease is often spread by apparently healthy cats, so even if a cat appears healthy, it may be infected and able to transmit the virus. Older cats are less likely to contract the infection, because resistance seems to increase with age. Symptoms include, but are not limited to: pale gums, yellow color in the mouth and whites of eyes, enlarged lymph nodes, bladder, skin, or upper respiratory infections, and weight loss and/or loss of appetite.
This disease can be diagnosed by a blood test called the ELISA and the phase at which its in can be tested by another blood test called the IFA (see extra research post). Cats who have been infected but have recovered should receive regular veterinary check-ups and good preventive health care to help protect them from secondary infection. Twice-yearly physical examinations, laboratory testing, and parasite control can prevent complications and identify problems quickly. All FeLV infected cats should be kept indoors and be neutered in order to not spread the disease. In addition, vaccines can be given to cats at high risk of exposure, such as those who go outside or live in shelters or catteries, but only cats that test negative for FeLV should be vaccinated. The prognosis for this virus is fairly positive though, as 70% of cats who encounter the virus are able to resist infection or eliminate the virus on their own.
Feline leukemia virus (FeLV) is the second leading cause of death in cats, killing 85% of continually infected felines within three years of their diagnosis. This virus commonly causes anemia (low red blood cell count) or lymphoma (cancer in lymph nodes), but because it is highly immunosuppressive, it can expose cats to other deadly diseases. Feline leukemia is a disease that only affects cats and is passed from one cat to another through mainly saliva and blood. Grooming and fighting seem to be the common ways for the infection to spread, however kittens can contract the disease through an infected mother’s milk. The disease is often spread by apparently healthy cats, so even if a cat appears healthy, it may be infected and able to transmit the virus. Older cats are less likely to contract the infection, because resistance seems to increase with age. Symptoms include, but are not limited to: pale gums, yellow color in the mouth and whites of eyes, enlarged lymph nodes, bladder, skin, or upper respiratory infections, and weight loss and/or loss of appetite.
This disease can be diagnosed by a blood test called the ELISA and the phase at which its in can be tested by another blood test called the IFA (see extra research post). Cats who have been infected but have recovered should receive regular veterinary check-ups and good preventive health care to help protect them from secondary infection. Twice-yearly physical examinations, laboratory testing, and parasite control can prevent complications and identify problems quickly. All FeLV infected cats should be kept indoors and be neutered in order to not spread the disease. In addition, vaccines can be given to cats at high risk of exposure, such as those who go outside or live in shelters or catteries, but only cats that test negative for FeLV should be vaccinated. The prognosis for this virus is fairly positive though, as 70% of cats who encounter the virus are able to resist infection or eliminate the virus on their own.
Fibrosarcomas in Cats
Fibrosarcoma is a locally aggressive cancer of the soft tissues (typically skin) that is relatively common in cats. Rates of occurrence range from 1 in 1,000 to 1 in 10,000 cats. The tumor is slow to metastasize, but is locally aggressive. Cancers are caused by a myriad of environmental and genetic factors, so a specific cause may not be identifiable. However, it is interesting to note that many cats with fibrosarcomas have developed the tumor at a prior vaccine/injection site, making it a VAS, or vaccine-associated sarcoma.
Most cats with fibrosarcomas present themselves as a mass of skin occurring at a historical vaccine/injection site. According to veterinarians, there are no signs of discomfort or pain. In more advanced cases, as an effect of the tumor, cats can become dehydrated, lethargic, or anorexic. To test for this disease, routine screening urinalysis, CBC and chemistry (see extra research) are performed to cancel out any other underlying diseases. Then, thoracic radiographs are taken to evaluate for metastatic disease. A biopsy or aspiration of the tumor will most likely also be required.
The first option for treatment is surgery, but because the tumor is locally aggressive, wide surgical margins are essential. Even with these wide surgical margins, however, local recurrence is common. For this reason, a secondary form of therapy is often required. Radiation therapy is the most commonly recommended second form of therapy that may be performed prior to or after surgery. The chemotherapy drugs used for this disease generally cause few evident side effects and are well tolerated. Fibrosarcoma carries a varied prognosis. Small tumors with aggressive surgical resection may never recur, but larger tumors, or tumors that are incompletely resected, will certainly recur and become locally aggressive within a matter of months after surgery. With a combination of radiation, surgery, and chemotherapy, however, the long term prognosis is much improved.
Fibrosarcoma is a locally aggressive cancer of the soft tissues (typically skin) that is relatively common in cats. Rates of occurrence range from 1 in 1,000 to 1 in 10,000 cats. The tumor is slow to metastasize, but is locally aggressive. Cancers are caused by a myriad of environmental and genetic factors, so a specific cause may not be identifiable. However, it is interesting to note that many cats with fibrosarcomas have developed the tumor at a prior vaccine/injection site, making it a VAS, or vaccine-associated sarcoma.
Most cats with fibrosarcomas present themselves as a mass of skin occurring at a historical vaccine/injection site. According to veterinarians, there are no signs of discomfort or pain. In more advanced cases, as an effect of the tumor, cats can become dehydrated, lethargic, or anorexic. To test for this disease, routine screening urinalysis, CBC and chemistry (see extra research) are performed to cancel out any other underlying diseases. Then, thoracic radiographs are taken to evaluate for metastatic disease. A biopsy or aspiration of the tumor will most likely also be required.
The first option for treatment is surgery, but because the tumor is locally aggressive, wide surgical margins are essential. Even with these wide surgical margins, however, local recurrence is common. For this reason, a secondary form of therapy is often required. Radiation therapy is the most commonly recommended second form of therapy that may be performed prior to or after surgery. The chemotherapy drugs used for this disease generally cause few evident side effects and are well tolerated. Fibrosarcoma carries a varied prognosis. Small tumors with aggressive surgical resection may never recur, but larger tumors, or tumors that are incompletely resected, will certainly recur and become locally aggressive within a matter of months after surgery. With a combination of radiation, surgery, and chemotherapy, however, the long term prognosis is much improved.
Fine Needle Aspiration
Fine needle aspiration is a type of biopsy procedure. In fine needle aspiration, a thin needle is inserted into an area of abnormal-appearing tissue or body fluid. As with other types of biopsies, the sample collected during fine needle aspiration can help make a diagnosis or rule out conditions such as cancer. To begin, a sterile, fine, gauge needle is attached to an empty syringe. The needle is stuck into the tissue and the plunger of the syringe is pulled back while the needle is held in the tissue. This creates suction, which aspirates tissue cells or fluid from the site into the syringe. When the needle with suction is inserted into the tissue, a number of cells get drawn into the needle. This sample is immediately and gently expelled onto a clean glass slide, spread in a thin layer, and rapidly dried by waving the slide in the air or by placing it in front of a fan or portable hair dryer (called an air-dried smear). The slide is then stained with special dyes and examined under the microscope.
If the sample is a fluid, air-dried smears are often prepared directly from the sample in the syringe, and the remaining fluid is placed in different tubes or containers. The smears and the containers are then sent to the laboratory for further analysis. Further analysis in a lab usually consists of measurement of the cellularity (number of type of cells in the sample) and amount of protein in the fluid, as well as the creation of additional slides. If the sample is very thin and watery, sometimes the sample is concentrated before the slides are made, which creates more cells to look at. The slides are then stained with special dyes and examined.
Fine needle aspiration is a type of biopsy procedure. In fine needle aspiration, a thin needle is inserted into an area of abnormal-appearing tissue or body fluid. As with other types of biopsies, the sample collected during fine needle aspiration can help make a diagnosis or rule out conditions such as cancer. To begin, a sterile, fine, gauge needle is attached to an empty syringe. The needle is stuck into the tissue and the plunger of the syringe is pulled back while the needle is held in the tissue. This creates suction, which aspirates tissue cells or fluid from the site into the syringe. When the needle with suction is inserted into the tissue, a number of cells get drawn into the needle. This sample is immediately and gently expelled onto a clean glass slide, spread in a thin layer, and rapidly dried by waving the slide in the air or by placing it in front of a fan or portable hair dryer (called an air-dried smear). The slide is then stained with special dyes and examined under the microscope.
If the sample is a fluid, air-dried smears are often prepared directly from the sample in the syringe, and the remaining fluid is placed in different tubes or containers. The smears and the containers are then sent to the laboratory for further analysis. Further analysis in a lab usually consists of measurement of the cellularity (number of type of cells in the sample) and amount of protein in the fluid, as well as the creation of additional slides. If the sample is very thin and watery, sometimes the sample is concentrated before the slides are made, which creates more cells to look at. The slides are then stained with special dyes and examined.
Hemangiosarcomas in Dogs
Hemangiosarcoma is cancer of the vascular endothelium, or the blood vessel walls. It makes up for 0.2 to 3 percent of all canine tumors with an average diagnosis age at 9 to 12 years. Hemangiosarcoma most commonly affects the spleen and heart of golden retrievers, Labrador retrievers and German shepherds. Along with that, it is estimated that 25 percent of dogs that present with splenic hemangiosarcoma also have a tumor of the heart. Forms that don't affect internal organs do occur, usually affecting the skin. Because metastasis and local invasion occur early in the course of this disease, many cases are not diagnosed until the ruptured tumor tissue causes a catastrophic hemorrhage.
Dogs with hemangiosarcoma may show non-specific signs such as lethargy and anorexia, which may come in episodes if small hemorrhages of the tumor occur repeatedly. Unfortunately, a common presentation is collapse, increased heart and respiratory rates, and pale mucous membranes caused by a large hemorrhage of a ruptured tumor. These mucous membranes can be inspected by lifting the upper lip to examine the color of the gums and lip. Even dogs with pigment on their gums will have some areas of pink to evaluate. Regular performance of this exam is crucial, as prompt diagnosis and treatment of this disease is critical for survival if the disease is present. At the clinic, a veterinarian may palpate an enlarged spleen, or may find palpation is difficult due to the presence of a blood-filled abdomen. Bloodwork may reveal anemia (low red blood cell count), thrombocytopenia (low platelet count), or disseminated intravascular coagulation (a deadly coagulation disorder in which small blood clots occur throughout the system, blocking blood vessels and depleting coagulation agents). Radiographs and/or ultrasound may show an enlarged spleen with multiple pockets of air, free fluid in the abdomen, or masses in the heart or abdominal organs.
Examination of affected cells from a fine needle aspirate of the affected organ may be useful in diagnosing hemangiosarcoma, but the procedure carries risk, as it may trigger bleeding. Because hemangiosarcoma often is associated with substantial hemorrhages and a very poor prognosis, the difficult decision must often be made at the time of diagnosis to either have an emergency surgery to remove the bleeding tumor, or humanely euthanize the dog. However, emerging therapies for hemangiosarcoma, which include immunotherapy, antimetastatic agents, and mushroom extracts, show promise for prolonged survival and possibly a better prognosis.
Hemangiosarcoma is cancer of the vascular endothelium, or the blood vessel walls. It makes up for 0.2 to 3 percent of all canine tumors with an average diagnosis age at 9 to 12 years. Hemangiosarcoma most commonly affects the spleen and heart of golden retrievers, Labrador retrievers and German shepherds. Along with that, it is estimated that 25 percent of dogs that present with splenic hemangiosarcoma also have a tumor of the heart. Forms that don't affect internal organs do occur, usually affecting the skin. Because metastasis and local invasion occur early in the course of this disease, many cases are not diagnosed until the ruptured tumor tissue causes a catastrophic hemorrhage.
Dogs with hemangiosarcoma may show non-specific signs such as lethargy and anorexia, which may come in episodes if small hemorrhages of the tumor occur repeatedly. Unfortunately, a common presentation is collapse, increased heart and respiratory rates, and pale mucous membranes caused by a large hemorrhage of a ruptured tumor. These mucous membranes can be inspected by lifting the upper lip to examine the color of the gums and lip. Even dogs with pigment on their gums will have some areas of pink to evaluate. Regular performance of this exam is crucial, as prompt diagnosis and treatment of this disease is critical for survival if the disease is present. At the clinic, a veterinarian may palpate an enlarged spleen, or may find palpation is difficult due to the presence of a blood-filled abdomen. Bloodwork may reveal anemia (low red blood cell count), thrombocytopenia (low platelet count), or disseminated intravascular coagulation (a deadly coagulation disorder in which small blood clots occur throughout the system, blocking blood vessels and depleting coagulation agents). Radiographs and/or ultrasound may show an enlarged spleen with multiple pockets of air, free fluid in the abdomen, or masses in the heart or abdominal organs.
Examination of affected cells from a fine needle aspirate of the affected organ may be useful in diagnosing hemangiosarcoma, but the procedure carries risk, as it may trigger bleeding. Because hemangiosarcoma often is associated with substantial hemorrhages and a very poor prognosis, the difficult decision must often be made at the time of diagnosis to either have an emergency surgery to remove the bleeding tumor, or humanely euthanize the dog. However, emerging therapies for hemangiosarcoma, which include immunotherapy, antimetastatic agents, and mushroom extracts, show promise for prolonged survival and possibly a better prognosis.
The Study of Histology
Lipomas in Dogs
Lipomas are masses or tumors that develop commonly in dogs underneath the skin. They are usually soft, with limited mobility under the skin. The overlying skin is usually not affected. Over time they can grow larger and can impede movement if they are located between the legs or low on the chest. Most dogs that develop a lipoma will develop multiple tumors, but it is important to recognize that additional masses do not necessarily indicate malignancy or metastasis. Since other masses on the skin may appear similar to lipomas, it is recommended that every mass be checked individually. There are many classifications of lipomas, one being the benign infiltrative lipomas. These typically invade locally into muscle tissue and fascia and may need to be removed. Liposarcomas, on the other hand, are malignant and can spread to the lungs, bone and other organs. These tumors are rare, but emphasize the importance of examining all subcutaneous (underneath the skin) masses.
Most lipomas feel soft and movable under the skin. They usually do not make pets uncomfortable unless they are in a location where normal movement is disrupted, like under the front leg. Often they are located on the belly or trunk, but can be anywhere on the dog’s body. Most dogs with one lipoma will eventually develop several. At a clinic, after a physical examination, a fine needle aspirate will indicate whether the mass is a benign lipoma or a more serious mass passing as a lipoma. If the aspirate is inconclusive, surgical removal may be necessary to arrive at a clear diagnosis.
Most dogs will not need to have their lipomas removed. However, if the lipoma is restricting movement in any way it will be necessary for your dog's comfort to remove the lipoma. In addition, if any diagnostics conclude that the mass may be a more aggressive tumor, it is usually advised to have the mass removed. Removal tends to be a simple process if the mass is small because lipomas are benign and a large margin is not needed. It is important to note that there are other subcutaneous masses, such as mast cell tumors, that can mimic the appearance of a lipoma. Therefore, it is vital to make sure that every mass is examined individually in case one of the masses is malignant. A dog's lipomas must be constantly monitored for any changes in size, number or location.
Lipomas are masses or tumors that develop commonly in dogs underneath the skin. They are usually soft, with limited mobility under the skin. The overlying skin is usually not affected. Over time they can grow larger and can impede movement if they are located between the legs or low on the chest. Most dogs that develop a lipoma will develop multiple tumors, but it is important to recognize that additional masses do not necessarily indicate malignancy or metastasis. Since other masses on the skin may appear similar to lipomas, it is recommended that every mass be checked individually. There are many classifications of lipomas, one being the benign infiltrative lipomas. These typically invade locally into muscle tissue and fascia and may need to be removed. Liposarcomas, on the other hand, are malignant and can spread to the lungs, bone and other organs. These tumors are rare, but emphasize the importance of examining all subcutaneous (underneath the skin) masses.
Most lipomas feel soft and movable under the skin. They usually do not make pets uncomfortable unless they are in a location where normal movement is disrupted, like under the front leg. Often they are located on the belly or trunk, but can be anywhere on the dog’s body. Most dogs with one lipoma will eventually develop several. At a clinic, after a physical examination, a fine needle aspirate will indicate whether the mass is a benign lipoma or a more serious mass passing as a lipoma. If the aspirate is inconclusive, surgical removal may be necessary to arrive at a clear diagnosis.
Most dogs will not need to have their lipomas removed. However, if the lipoma is restricting movement in any way it will be necessary for your dog's comfort to remove the lipoma. In addition, if any diagnostics conclude that the mass may be a more aggressive tumor, it is usually advised to have the mass removed. Removal tends to be a simple process if the mass is small because lipomas are benign and a large margin is not needed. It is important to note that there are other subcutaneous masses, such as mast cell tumors, that can mimic the appearance of a lipoma. Therefore, it is vital to make sure that every mass is examined individually in case one of the masses is malignant. A dog's lipomas must be constantly monitored for any changes in size, number or location.
Lymphomas in Dogs
Lymphoma, a type of cancer from the uncontrolled division of white blood cells (lymphocytes), can be very dangerous if it spreads through the blood into other parts of the body. Dogs can develop several different forms of lymphoma, with the most common being multicentric lymphoma, which is detected by enlargement of the mandibular lymph nodes (under the jaw) and the popliteal lymph nodes (behind the knee). Other manifestations include alimentary lymphoma (which accounts for less than 10% of canine lymphomas) that targets the intestines, mediastinal lymphoma, (which is fairly rare) where either or both the thymus and mediastinal lymph nodes in the chest become enlarged, and extranodal lymphoma, (otherwise know as cutaneous lymphoma) that targets a specific organ such as the skin, eyes, kidneys, lungs, or nervous system.
Though it may sound scary, lymphoma is a highly treatable cancer in dogs. The plan for treatment can vary, but usually involves dogs receiving treatment weekly or every other week. Chemotherapy is well-tolerated in dogs, with minimal side effects.
Lymphoma, a type of cancer from the uncontrolled division of white blood cells (lymphocytes), can be very dangerous if it spreads through the blood into other parts of the body. Dogs can develop several different forms of lymphoma, with the most common being multicentric lymphoma, which is detected by enlargement of the mandibular lymph nodes (under the jaw) and the popliteal lymph nodes (behind the knee). Other manifestations include alimentary lymphoma (which accounts for less than 10% of canine lymphomas) that targets the intestines, mediastinal lymphoma, (which is fairly rare) where either or both the thymus and mediastinal lymph nodes in the chest become enlarged, and extranodal lymphoma, (otherwise know as cutaneous lymphoma) that targets a specific organ such as the skin, eyes, kidneys, lungs, or nervous system.
Though it may sound scary, lymphoma is a highly treatable cancer in dogs. The plan for treatment can vary, but usually involves dogs receiving treatment weekly or every other week. Chemotherapy is well-tolerated in dogs, with minimal side effects.
Lymphomas in Cats
Lymphoma is a cancer of a specific white blood cell called the lymphocyte, which is the major cell found in lymph nodes. The lymph system is found in blood and tissues throughout the body and is a network of vessels and nodes through which foreign proteins and disease organisms are circulated. Lymphocytes have a number of roles in the immune system, including the production of antibodies and other substances that fight infection and disease. With lymphoma, the cancer cells invade and destroy normal tissues. In cats, lymphoma cells (like lymphocytes) can grow anywhere in the body, but there are certain sites that are more commonly affected by lymphoma than others.
A cat with lymphoma may not show it right away. Progressive lack of appetite, lethargy and weight loss are among the most common. Depending on which organs are affected, other signs, such as chronic diarrhea, vomiting and difficulty in breathing, may occur. Many diseases can cause similar symptoms, and as with any problem, a veterinarian should diagnose the cat.
Feline lymphoma has several different forms and can appear almost anywhere and affect a wide number of organs. However, lymphoma most commonly appears in three parts of the body. The location is often associated with the cause of the lymphoma and will influence the symptoms, treatment, and prognosis. The multicentric form involves multiple lymph nodes and possibly multiple organs. This form is more closely associated with feline leukemia and the prognosis is not as good if the cat is feline leukemia positive. The mediastinal form has also been associated with feline leukemia, although recently there have been more cats with this type of lymphoma that do not have feline leukemia. This form is found in the chest cavity and will affect the thymus and associated lymph nodes. The alimentary form affects the digestive tract and surrounding lymph nodes. This form is least likely to be associated with feline leukemia. Alimentary (intestinal) lymphoma is the most common form of lymphoma in cats.
Treatment usually consists of chemotherapy and a combination of drugs administered over several weeks. During the course of treatment white and red blood cell numbers are closely monitored. In a few isolated cases (where the tumor is localized and easily accessible) surgery or radiation therapy may be used. It is rare to cure lymphoma, but chemotherapy increases the chances of long-term survival and, in most, will extend the quantity and quality of life.
Side effects such as nausea and anorexia are occasionally noted in response to the chemo, however the most common side effect is bone marrow suppression. While whiskers are commonly lost, animals on chemotherapy do not experience substantial hair loss. Unfortunately, the only way to know whether an animal is going to have a drug reaction is to administer the drug. Some cats never get sick during chemotherapy, while others are very sensitive to the drugs. However, all in all, chemotherapy is a fairly successful treatment.
Lymphoma is a cancer of a specific white blood cell called the lymphocyte, which is the major cell found in lymph nodes. The lymph system is found in blood and tissues throughout the body and is a network of vessels and nodes through which foreign proteins and disease organisms are circulated. Lymphocytes have a number of roles in the immune system, including the production of antibodies and other substances that fight infection and disease. With lymphoma, the cancer cells invade and destroy normal tissues. In cats, lymphoma cells (like lymphocytes) can grow anywhere in the body, but there are certain sites that are more commonly affected by lymphoma than others.
A cat with lymphoma may not show it right away. Progressive lack of appetite, lethargy and weight loss are among the most common. Depending on which organs are affected, other signs, such as chronic diarrhea, vomiting and difficulty in breathing, may occur. Many diseases can cause similar symptoms, and as with any problem, a veterinarian should diagnose the cat.
Feline lymphoma has several different forms and can appear almost anywhere and affect a wide number of organs. However, lymphoma most commonly appears in three parts of the body. The location is often associated with the cause of the lymphoma and will influence the symptoms, treatment, and prognosis. The multicentric form involves multiple lymph nodes and possibly multiple organs. This form is more closely associated with feline leukemia and the prognosis is not as good if the cat is feline leukemia positive. The mediastinal form has also been associated with feline leukemia, although recently there have been more cats with this type of lymphoma that do not have feline leukemia. This form is found in the chest cavity and will affect the thymus and associated lymph nodes. The alimentary form affects the digestive tract and surrounding lymph nodes. This form is least likely to be associated with feline leukemia. Alimentary (intestinal) lymphoma is the most common form of lymphoma in cats.
Treatment usually consists of chemotherapy and a combination of drugs administered over several weeks. During the course of treatment white and red blood cell numbers are closely monitored. In a few isolated cases (where the tumor is localized and easily accessible) surgery or radiation therapy may be used. It is rare to cure lymphoma, but chemotherapy increases the chances of long-term survival and, in most, will extend the quantity and quality of life.
Side effects such as nausea and anorexia are occasionally noted in response to the chemo, however the most common side effect is bone marrow suppression. While whiskers are commonly lost, animals on chemotherapy do not experience substantial hair loss. Unfortunately, the only way to know whether an animal is going to have a drug reaction is to administer the drug. Some cats never get sick during chemotherapy, while others are very sensitive to the drugs. However, all in all, chemotherapy is a fairly successful treatment.
Mammary Cancer in Cats
Cancer in the mammary glands of cats affect the milk-producing organs of females, but can affect males as well. Over 85% of mammary tumors in cats are malignant and they tend to grow and spread quickly. Like breast tumors in humans, they start as a small lump in a mammary gland. Often, more than one mammary gland is affected. This disease is preventable by having female cats spayed before six months of age. Mammary gland tumors begin as masses underneath the skin. However, over time they can become aggressive and ulcerate the skin. Cats tend to lick and groom the area excessively, and a strong odor can result as the tumor becomes infected. General signs of ill health like anorexia or depression are often seen as the disease progresses.
A fine needle aspirate is typically the tool used to determine whether a small mass is a mammary tumor. An incisional biopsy may also be discussed, but if a fine needle aspirate does not fully diagnose the tumor, complete removal, including wide margins of tissue around the mass, may be recommended due to a high rate of malignancy. Additional blood work may also be recommended to further determine diagnosis and treatments, however each cat should be thoroughly evaluated before a treatment plan is made since aggressive treatment may not be the best option.
The treatment of choice is surgical removal of the mass and significant surrounding tissue. Depending on the stage of the mammary tumor and area affected, the veterinarian may advise that the regional lymph nodes or additional mammary glands be removed at the time of surgery. All mammary tissue on the right or left side may be removed to prevent further risk to the tissue. In addition, chemotherapy can be used as a treatment. General health factors must be considered in any treatment plan, and consulting with a veterinary oncologist is helpful.
Making the cat comfortable during the remainder of its life is an important goal in treatment. Prescription pet medications that limit pain or anxiety associated with the mammary tumors may be prescribed. Frequent check-ups are important to identify if the cancer has returned or metastasized.Fortunately, by spaying cats before the age of six months, the risk of mammary cancer is limited considerably. Less is known about spaying older cats with mammary gland tumors, but it is usually recommended.
Cancer in the mammary glands of cats affect the milk-producing organs of females, but can affect males as well. Over 85% of mammary tumors in cats are malignant and they tend to grow and spread quickly. Like breast tumors in humans, they start as a small lump in a mammary gland. Often, more than one mammary gland is affected. This disease is preventable by having female cats spayed before six months of age. Mammary gland tumors begin as masses underneath the skin. However, over time they can become aggressive and ulcerate the skin. Cats tend to lick and groom the area excessively, and a strong odor can result as the tumor becomes infected. General signs of ill health like anorexia or depression are often seen as the disease progresses.
A fine needle aspirate is typically the tool used to determine whether a small mass is a mammary tumor. An incisional biopsy may also be discussed, but if a fine needle aspirate does not fully diagnose the tumor, complete removal, including wide margins of tissue around the mass, may be recommended due to a high rate of malignancy. Additional blood work may also be recommended to further determine diagnosis and treatments, however each cat should be thoroughly evaluated before a treatment plan is made since aggressive treatment may not be the best option.
The treatment of choice is surgical removal of the mass and significant surrounding tissue. Depending on the stage of the mammary tumor and area affected, the veterinarian may advise that the regional lymph nodes or additional mammary glands be removed at the time of surgery. All mammary tissue on the right or left side may be removed to prevent further risk to the tissue. In addition, chemotherapy can be used as a treatment. General health factors must be considered in any treatment plan, and consulting with a veterinary oncologist is helpful.
Making the cat comfortable during the remainder of its life is an important goal in treatment. Prescription pet medications that limit pain or anxiety associated with the mammary tumors may be prescribed. Frequent check-ups are important to identify if the cancer has returned or metastasized.Fortunately, by spaying cats before the age of six months, the risk of mammary cancer is limited considerably. Less is known about spaying older cats with mammary gland tumors, but it is usually recommended.
Mammary Gland Carcinomas in Dogs
Tumors of the mammary glands, both benign and malignant, occur fairly frequently in unspayed female dogs. In fact, for unspayed female dogs, they are the most common type of tumor. Spaying can largely reduce the risk of developing this type of cancer, especially if the dog is spayed before it has an opportunity to go into heat. There are two main types of mammary gland breast tumors, each with several subtypes of tumor growth. While this condition is more likely to occur in the female population, it does also affect male dogs, albeit rarely. When a male dog is affected by a tumor of the breast, though, the prognosis is much more serious.
There are some breeds that are predisposed to cancer of the mammary glands, like toy and miniature poodles, English springer spaniels, Brittanys, cocker spaniels, English setters, pointers, German shepherd dogs, Maltese, and Yorkshire terriers. The median age is about 10 years and is less common in dogs younger than five. Dogs with this type of cancer will experience slow-growing single or multiple masses in the mammary glands. They may also have superficial loss of tissue on the surface of the skin over the mammary tissue, frequently with inflammation. There are two main indicators that show whether the tumor is malignant or benign: if the mass is freely movable, this is usually benign, but if the mass is fixed to skin or body wall, this is usually malignant.
About half of the affected dogs will be diagnosed with the benign form of mammary tumors, but the approximate other half of dogs will be diagnosed with a malignant form of tumor. To decide on a complete diagnosis, a chemical blood profile, a complete blood count, and a urine analysis will be conducted. Diagnostics may include X-rays of the chest and abdomen, which could detect any metastasis. It also may be necessary to conduct a biopsy of the mass to fully determine its nature and the lymph nodes will also be examined.
Surgery is the go-to form of treatment, as the tumor(s) will most likely need to be removed. Depending on the age of the dog, the type of tumor, and the rate at which the tumors have metastasized, a doctor may remove the tumor only, or all of the tumor along with the surrounding tissue, lymph nodes and mammary glands. Some types of tumor are more invasive, rotting deeper into the tissue or bone, making then very difficult to remove. In these cases, partial removal of the cancerous mass and surrounding tissue may be performed, and chemotherapy may be an option, but use of chemotherapy for breast or mammary tumors is not typically used.
Spaying bitches who are still intact at the time of surgical removal of the breast or affected mammary tissue is often the preferred method, and this may enhance survival as it decreases the possibility of recurrence. However, this depends on the age of the dog as well. If the dog is older, this method will not be as beneficial.
Spaying before the first heat will greatly reduce the dog's risk for developing breast or mammary tumors compared to an intact bitch. Spaying before the first heat is also proven to markedly decrease the likelihood of developing mammary tumors. Early spaying is the best method for prevention of this form of cancer. If spaying is delayed until before the second heat the risk of developing breast or mammary tumors compared to intact bitches increases to 8 percent.
If spaying is still delayed until after the second heat, there is a 26 percent risk of developing breast or mammary tumors.
The prognosis and course the disease will take varies with the type of breast or mammary tumor the dog has, as well as the size of the tumor, and the presence of metastasis.
A breast or mammary nodule should never be ignored, as it can quickly metastasize when it is the malignant form, thus spreading throughout the body and becoming untreatable before its severity is recognized. Early detection and thorough surgical intervention is best to improve the prognosis.
Tumors of the mammary glands, both benign and malignant, occur fairly frequently in unspayed female dogs. In fact, for unspayed female dogs, they are the most common type of tumor. Spaying can largely reduce the risk of developing this type of cancer, especially if the dog is spayed before it has an opportunity to go into heat. There are two main types of mammary gland breast tumors, each with several subtypes of tumor growth. While this condition is more likely to occur in the female population, it does also affect male dogs, albeit rarely. When a male dog is affected by a tumor of the breast, though, the prognosis is much more serious.
There are some breeds that are predisposed to cancer of the mammary glands, like toy and miniature poodles, English springer spaniels, Brittanys, cocker spaniels, English setters, pointers, German shepherd dogs, Maltese, and Yorkshire terriers. The median age is about 10 years and is less common in dogs younger than five. Dogs with this type of cancer will experience slow-growing single or multiple masses in the mammary glands. They may also have superficial loss of tissue on the surface of the skin over the mammary tissue, frequently with inflammation. There are two main indicators that show whether the tumor is malignant or benign: if the mass is freely movable, this is usually benign, but if the mass is fixed to skin or body wall, this is usually malignant.
About half of the affected dogs will be diagnosed with the benign form of mammary tumors, but the approximate other half of dogs will be diagnosed with a malignant form of tumor. To decide on a complete diagnosis, a chemical blood profile, a complete blood count, and a urine analysis will be conducted. Diagnostics may include X-rays of the chest and abdomen, which could detect any metastasis. It also may be necessary to conduct a biopsy of the mass to fully determine its nature and the lymph nodes will also be examined.
Surgery is the go-to form of treatment, as the tumor(s) will most likely need to be removed. Depending on the age of the dog, the type of tumor, and the rate at which the tumors have metastasized, a doctor may remove the tumor only, or all of the tumor along with the surrounding tissue, lymph nodes and mammary glands. Some types of tumor are more invasive, rotting deeper into the tissue or bone, making then very difficult to remove. In these cases, partial removal of the cancerous mass and surrounding tissue may be performed, and chemotherapy may be an option, but use of chemotherapy for breast or mammary tumors is not typically used.
Spaying bitches who are still intact at the time of surgical removal of the breast or affected mammary tissue is often the preferred method, and this may enhance survival as it decreases the possibility of recurrence. However, this depends on the age of the dog as well. If the dog is older, this method will not be as beneficial.
Spaying before the first heat will greatly reduce the dog's risk for developing breast or mammary tumors compared to an intact bitch. Spaying before the first heat is also proven to markedly decrease the likelihood of developing mammary tumors. Early spaying is the best method for prevention of this form of cancer. If spaying is delayed until before the second heat the risk of developing breast or mammary tumors compared to intact bitches increases to 8 percent.
If spaying is still delayed until after the second heat, there is a 26 percent risk of developing breast or mammary tumors.
The prognosis and course the disease will take varies with the type of breast or mammary tumor the dog has, as well as the size of the tumor, and the presence of metastasis.
A breast or mammary nodule should never be ignored, as it can quickly metastasize when it is the malignant form, thus spreading throughout the body and becoming untreatable before its severity is recognized. Early detection and thorough surgical intervention is best to improve the prognosis.
Oral Melanomas in Dogs
Melanoma, cancer of the melanocytes (the pigment-producing cells of the body) is most commonly found for dogs in the mouth. Melanoma is a very aggressive disease and tumors are often very large, frequently invading the surrounding bones of the oral cavity before they are even detected. Oral melanomas also have a high chance of metastasizing to other parts of the body. From the mouth, the most common locations for melanoma to spread are lymph nodes within the head and neck and the lungs. Certain breeds are more likely to develop melanoma tumors than others, including poodles, dachshunds, Scottish terriers, and golden retrievers.
The primary treatment for oral melanoma in dogs is surgical removal of the tumor, however, since the majority of tumors invade the boney structures of the jaw, complete removal can be difficult. When the tumor cannot be completely removed and/or it has spread to local lymph nodes of the head and neck (but not beyond), radiation therapy becomes important in the treatment of this disease.
For cases of oral melanoma that have spread to more distant sites, like the lungs, veterinarians have relied on chemotherapy as a form of treatment. Unfortunately, melanoma seems to be inherently resistant to chemotherapeutic drugs, and response rates and durations are disappointing. Studies do not indicate a survival benefit to adding chemotherapy to aggressive surgery and/or radiation therapy plans.
Fortunately though, recent technological advancements have allowed the development of a DNA-based vaccine as a treatment option for canine oral melanoma. This form of treatment, called immunotherapy, is based upon the concept of using the body’s own immune system to control the growth of, or potentially even eradicate, tumor cells. The melanoma vaccine contains the human DNA sequence encoding a specific protein only found within melanocytes called tyrosinase. Tyrosinase is an enzyme crucial to the melanocyte’s ability to produce melanin (pigment), and also to the survival of the melanocyte itself. Once injected into the dog, the human DNA segment is processed so the dog’s body actually generates small amounts of the human tyrosinase protein. The human tyrosinase protein is similar enough in structure to the dog’s own natural tyrosinase protein, so this very same immune response is effective in attacking the tyrosinase that is present in its own melanoma cells. The end result is destruction of the tyrosinase in the cancerous melanoma cells, and ultimately, the inability of the tumor cells to survive. This leaves a positive prognosis for the dog.
Melanoma, cancer of the melanocytes (the pigment-producing cells of the body) is most commonly found for dogs in the mouth. Melanoma is a very aggressive disease and tumors are often very large, frequently invading the surrounding bones of the oral cavity before they are even detected. Oral melanomas also have a high chance of metastasizing to other parts of the body. From the mouth, the most common locations for melanoma to spread are lymph nodes within the head and neck and the lungs. Certain breeds are more likely to develop melanoma tumors than others, including poodles, dachshunds, Scottish terriers, and golden retrievers.
The primary treatment for oral melanoma in dogs is surgical removal of the tumor, however, since the majority of tumors invade the boney structures of the jaw, complete removal can be difficult. When the tumor cannot be completely removed and/or it has spread to local lymph nodes of the head and neck (but not beyond), radiation therapy becomes important in the treatment of this disease.
For cases of oral melanoma that have spread to more distant sites, like the lungs, veterinarians have relied on chemotherapy as a form of treatment. Unfortunately, melanoma seems to be inherently resistant to chemotherapeutic drugs, and response rates and durations are disappointing. Studies do not indicate a survival benefit to adding chemotherapy to aggressive surgery and/or radiation therapy plans.
Fortunately though, recent technological advancements have allowed the development of a DNA-based vaccine as a treatment option for canine oral melanoma. This form of treatment, called immunotherapy, is based upon the concept of using the body’s own immune system to control the growth of, or potentially even eradicate, tumor cells. The melanoma vaccine contains the human DNA sequence encoding a specific protein only found within melanocytes called tyrosinase. Tyrosinase is an enzyme crucial to the melanocyte’s ability to produce melanin (pigment), and also to the survival of the melanocyte itself. Once injected into the dog, the human DNA segment is processed so the dog’s body actually generates small amounts of the human tyrosinase protein. The human tyrosinase protein is similar enough in structure to the dog’s own natural tyrosinase protein, so this very same immune response is effective in attacking the tyrosinase that is present in its own melanoma cells. The end result is destruction of the tyrosinase in the cancerous melanoma cells, and ultimately, the inability of the tumor cells to survive. This leaves a positive prognosis for the dog.
Osteosarcomas (Bone Cancer) in Dogs
Osteosarcoma, cancer in the bones, is the most common type of bone tumor found in dogs. Bone cancer can affect any breed of dog, but it is more commonly found in the larger breeds. The disease is extremely aggressive and has a tendency to spread rapidly into other parts of the dog's body. There are treatment options available, but sadly, the long term prognosis for the animal is poor.
Many symptoms of bone cancer are subtle. They can include swelling lameness, and joint or bone pain. In some cases, dogs suffering from bone cancer will appear tired or have a reluctance to eat. Occasionally, dogs will exhibit a mass growth on their body or a painful inflammation around the site of the tumor. Though genetics are not shown to play a significant role in the development of this, bone cancer does appear more often in large to giant breeds of dogs.
A veterinarian will use X-rays to view the mass, and possibly other tests such as biopsies, blood tests, bone scans, and CAT scans to view the bone areas. If the diagnosis is bone cancer, it is important to note that the prognosis is often unfavorable and that there are numerous side effects to the treatment options. Chemotherapy is often used as a supplement to any surgical options to ensure that the disease has not spread into other areas of the dog's body. In severe cases though, limbs may need to be amputated to completely remove the bone cancer.
Osteosarcoma, cancer in the bones, is the most common type of bone tumor found in dogs. Bone cancer can affect any breed of dog, but it is more commonly found in the larger breeds. The disease is extremely aggressive and has a tendency to spread rapidly into other parts of the dog's body. There are treatment options available, but sadly, the long term prognosis for the animal is poor.
Many symptoms of bone cancer are subtle. They can include swelling lameness, and joint or bone pain. In some cases, dogs suffering from bone cancer will appear tired or have a reluctance to eat. Occasionally, dogs will exhibit a mass growth on their body or a painful inflammation around the site of the tumor. Though genetics are not shown to play a significant role in the development of this, bone cancer does appear more often in large to giant breeds of dogs.
A veterinarian will use X-rays to view the mass, and possibly other tests such as biopsies, blood tests, bone scans, and CAT scans to view the bone areas. If the diagnosis is bone cancer, it is important to note that the prognosis is often unfavorable and that there are numerous side effects to the treatment options. Chemotherapy is often used as a supplement to any surgical options to ensure that the disease has not spread into other areas of the dog's body. In severe cases though, limbs may need to be amputated to completely remove the bone cancer.
Pulmonary Neoplasia (Lung Tumors) in Dogs
In dogs (and also cats), lung lobe (“pulmonary”) tumors are most frequently a result of cancer cells that have been carried by the blood stream into the lung tissue. Primary lung tumors, or tumors that originate from the lung tissue, are much less common. Most come from glandular structures, known as “adenocarcinoma” or “bronchogenic carcinoma,” but they can also come from portions of the lung tissue that provide support, such as fibrosarcomas that come from fibrous tissue, chondrosarcomas that come from cartilage, and hemangiosarcomas, that come from blood vessels. Dogs that live in a household with smokers, or in environments high in some pollutants, such as asbestos, are at an increased risk for developing primary lung lobe tumors. Brachycephalic breeds (bulldogs, pugs, etc.), with their flat noses, are also at a greater risk than long nosed breeds. Dogs that have with primary lung tumors are usually middle-aged or older.
The scariest thing about this issue is that about 25% of dogs will have no signs and the tumors are found accidentally in chest x-rays. On the other hand, some dogs may present with coughs,, weight loss, or lethargy, Tumors that are large or squish vital structures can cause difficulty breathing or sudden regurgitation, Some dogs may even have lameness because the lung lobe tumor has spread to other sites or has caused swelling and bony reaction along the toes and lower bones of the leg, known as “hypertrophic osteopathy.” These tumors can be removed surgically, and if it has not spread, there is generally a positive outlook for these dogs.
In dogs (and also cats), lung lobe (“pulmonary”) tumors are most frequently a result of cancer cells that have been carried by the blood stream into the lung tissue. Primary lung tumors, or tumors that originate from the lung tissue, are much less common. Most come from glandular structures, known as “adenocarcinoma” or “bronchogenic carcinoma,” but they can also come from portions of the lung tissue that provide support, such as fibrosarcomas that come from fibrous tissue, chondrosarcomas that come from cartilage, and hemangiosarcomas, that come from blood vessels. Dogs that live in a household with smokers, or in environments high in some pollutants, such as asbestos, are at an increased risk for developing primary lung lobe tumors. Brachycephalic breeds (bulldogs, pugs, etc.), with their flat noses, are also at a greater risk than long nosed breeds. Dogs that have with primary lung tumors are usually middle-aged or older.
The scariest thing about this issue is that about 25% of dogs will have no signs and the tumors are found accidentally in chest x-rays. On the other hand, some dogs may present with coughs,, weight loss, or lethargy, Tumors that are large or squish vital structures can cause difficulty breathing or sudden regurgitation, Some dogs may even have lameness because the lung lobe tumor has spread to other sites or has caused swelling and bony reaction along the toes and lower bones of the leg, known as “hypertrophic osteopathy.” These tumors can be removed surgically, and if it has not spread, there is generally a positive outlook for these dogs.
Squamous Cell Carcinomas in Cats
Squamous cells are the flat, scale-like cells that create the outer layer of the epithelium (the tissue that lines the external and internal surfaces of the organs in a cat’s body). The main functions of these unique cells range from the protection of underlying tissue to the facilitation of nutrient exchange. Squamous cell carcinomas can be caused by a variety of influences, such as physical trauma or serious burns that damage these superficial cells.
The most common sites of development on a cat are the temples, the outer tips of the ears (pinnae), the eyelids, the lips, and the nose. About one-third of cats diagnosed with SCC of the skin have multiple lesions. Also seen with frequently are squamous cell tumors in the oral cavity. Oral cavity tumors account for only about three percent of feline cancers, but of these, approximately three-fourths are squamous cell tumors. Occasionally, though rarely, these carcinomas are seen developing in the liver, lungs and other internal organs. Although not scientifically confirmed, it is widely believed that these tumors are caused by exposure to certain environmental carcinogens — especially tobacco smoke.
External tumors are usually single, small and poorly outlined, with irregular, hardened borders. The surrounding area may be slightly pink, and there may be hair loss. The skin eruption is likely to be ulcerated and oozing fluid, and its surface may be concave. Although lesions can be highly invasive at their points of origin, they tend to spread slowly. As the tumor progresses, swelling will occur in the area, which is likely to be accompanied by tissue erosion around the lesion as the cancer progresses into deeper epithelial regions that may extend from the facial area into the nasal cavity and beyond. And, if it eventually metastasizes to a regional lymph node, it may then spread from there to other areas of the body.
The presence of SCC can be confirmed by a biopsy, and can be removed with surgery. Chemotherapy and cryotherapy (freezing the tumor) are also used as well, but are certainly less common. In addition to the emergence of a suspicious sore on an animal’s nose, ears, eyelids, lips or any other area of the body that is hairless, though, the warning signs of SCC in the mouth include excessive salivation and drooling, weight loss, bad breath, swelling of the upper or lower jaw and a decline in appetite. If it can be treated early, the outlook is generally pretty good.
Squamous cells are the flat, scale-like cells that create the outer layer of the epithelium (the tissue that lines the external and internal surfaces of the organs in a cat’s body). The main functions of these unique cells range from the protection of underlying tissue to the facilitation of nutrient exchange. Squamous cell carcinomas can be caused by a variety of influences, such as physical trauma or serious burns that damage these superficial cells.
The most common sites of development on a cat are the temples, the outer tips of the ears (pinnae), the eyelids, the lips, and the nose. About one-third of cats diagnosed with SCC of the skin have multiple lesions. Also seen with frequently are squamous cell tumors in the oral cavity. Oral cavity tumors account for only about three percent of feline cancers, but of these, approximately three-fourths are squamous cell tumors. Occasionally, though rarely, these carcinomas are seen developing in the liver, lungs and other internal organs. Although not scientifically confirmed, it is widely believed that these tumors are caused by exposure to certain environmental carcinogens — especially tobacco smoke.
External tumors are usually single, small and poorly outlined, with irregular, hardened borders. The surrounding area may be slightly pink, and there may be hair loss. The skin eruption is likely to be ulcerated and oozing fluid, and its surface may be concave. Although lesions can be highly invasive at their points of origin, they tend to spread slowly. As the tumor progresses, swelling will occur in the area, which is likely to be accompanied by tissue erosion around the lesion as the cancer progresses into deeper epithelial regions that may extend from the facial area into the nasal cavity and beyond. And, if it eventually metastasizes to a regional lymph node, it may then spread from there to other areas of the body.
The presence of SCC can be confirmed by a biopsy, and can be removed with surgery. Chemotherapy and cryotherapy (freezing the tumor) are also used as well, but are certainly less common. In addition to the emergence of a suspicious sore on an animal’s nose, ears, eyelids, lips or any other area of the body that is hairless, though, the warning signs of SCC in the mouth include excessive salivation and drooling, weight loss, bad breath, swelling of the upper or lower jaw and a decline in appetite. If it can be treated early, the outlook is generally pretty good.
The ELISA Blood Test
The enzyme-linked immunosorbent assay, also called ELISA, is a test that detects and measures antibodies in your blood. This test can be used to determine if you have antibodies related to certain infectious conditions. Antibodies are proteins that your body produces in response to harmful substances called antigens. This test is performed in a lab. First, a sample is taken at the veterinary clinic normally, then the blood sample is sent to a laboratory for analysis. In the lab, a technician will add the sample to a petri dish containing the specific antigen related to the condition for which you are being tested. If your blood contains antibodies to the antigen, the two will bind together. The technician will check this by adding an enzyme to the petri dish and observing how your blood and the antigen react.
The condition may be present if the contents of the dish change color. How much change the enzyme causes allows the technician to determine the presence and amount of antibody. It can be used to detect a variety of antigens in animals, including (but not limited to) Lyme disease, squamous cell carcinoma, and several blood-born illnesses.
The enzyme-linked immunosorbent assay, also called ELISA, is a test that detects and measures antibodies in your blood. This test can be used to determine if you have antibodies related to certain infectious conditions. Antibodies are proteins that your body produces in response to harmful substances called antigens. This test is performed in a lab. First, a sample is taken at the veterinary clinic normally, then the blood sample is sent to a laboratory for analysis. In the lab, a technician will add the sample to a petri dish containing the specific antigen related to the condition for which you are being tested. If your blood contains antibodies to the antigen, the two will bind together. The technician will check this by adding an enzyme to the petri dish and observing how your blood and the antigen react.
The condition may be present if the contents of the dish change color. How much change the enzyme causes allows the technician to determine the presence and amount of antibody. It can be used to detect a variety of antigens in animals, including (but not limited to) Lyme disease, squamous cell carcinoma, and several blood-born illnesses.
Thyroid Carcinomas in Dogs
Tumors from Mast Cells
Why do Dogs Chew their Paws?
Every source I have consulted has given me four main culprits as to why dogs will lick or chew on their feet, just like my own dog is doing. These culprits are:
1. An Allergic Reaction
Allergic skin disease is the most common reason why canines lick and chew their feet on a chronic basis. Food allergies, in particular, are typically the culprit, and secondary infections from yeast and bacteria can further exacerbate the behavior. A dog can also develop dermatitis, which can happens when a dog comes in contact with a skin irritant. Allergies to the cleaner used on floors, yards or flower gardens can cause a dog to react by chewing his feet. It’s also possible he’s allergic to his food, the carpet in his home or rugs he lays on.
2. Depression, Anxiety, or Boredom
Another reason why a dog could be chewing on his feet is because of an obsessive compulsive behavior. Dogs can develop Canine Compulsive Disorder, which is brought on by anxiety, stress, or boredom. Andrew Luescher, director of Purdue’s Animal Behavior Clinic and a board certified animal behaviorist, estimates that among the dog population, only 2% of dogs have canine compulsive disorder. Thankfully, this disorder is not a neurological problem. It’s a behavioral disorder that can be modified with medication and changing the dog’s behavior. A qualified animal behaviorist or veterinary behaviorist can help assist in changing a dog’s behavior.
A bored dog will also chew on his feet, which means he simply needs plenty of exercise and stimulation for both his body and mind. Going for walks, taking him to a local dog park or joining a dog club and participating in activities are good ways to keep the dog from being bored at home.
3. Pain in the Area
Arthritis or some other type of pain could be causing enough discomfort for a dog that he tries to relieve it by licking or chewing his foot. A dog’s paw pads are not immune to picking up rocks, thorns or other foreign objects they step on. They can cut their pads while romping in the backyard or playing at a dog park, and a hot sidewalk or road can burn their pads. Snow, road salt and ice can also build up between their pads during the winter months. Canines will also engage in this behavior due to other, more serious causes, such as interdigital cysts (lumps between their toes), tumors and other cancers, and autoimmune diseases of the nail beds or paw pads.
4. A Parasitic Microbe
A type of mange called Demodicosis mange (Red Mange) is a microscopic mite that affects one or more of a dog’s feet, and it’s a common skin disease in dogs. Yeast infection and flea allergies will also cause a dog to chew his feet.
Though there are many different reasons a dog may lick his paw, its always important to see a veterinarian if the problem persists.
Every source I have consulted has given me four main culprits as to why dogs will lick or chew on their feet, just like my own dog is doing. These culprits are:
1. An Allergic Reaction
Allergic skin disease is the most common reason why canines lick and chew their feet on a chronic basis. Food allergies, in particular, are typically the culprit, and secondary infections from yeast and bacteria can further exacerbate the behavior. A dog can also develop dermatitis, which can happens when a dog comes in contact with a skin irritant. Allergies to the cleaner used on floors, yards or flower gardens can cause a dog to react by chewing his feet. It’s also possible he’s allergic to his food, the carpet in his home or rugs he lays on.
2. Depression, Anxiety, or Boredom
Another reason why a dog could be chewing on his feet is because of an obsessive compulsive behavior. Dogs can develop Canine Compulsive Disorder, which is brought on by anxiety, stress, or boredom. Andrew Luescher, director of Purdue’s Animal Behavior Clinic and a board certified animal behaviorist, estimates that among the dog population, only 2% of dogs have canine compulsive disorder. Thankfully, this disorder is not a neurological problem. It’s a behavioral disorder that can be modified with medication and changing the dog’s behavior. A qualified animal behaviorist or veterinary behaviorist can help assist in changing a dog’s behavior.
A bored dog will also chew on his feet, which means he simply needs plenty of exercise and stimulation for both his body and mind. Going for walks, taking him to a local dog park or joining a dog club and participating in activities are good ways to keep the dog from being bored at home.
3. Pain in the Area
Arthritis or some other type of pain could be causing enough discomfort for a dog that he tries to relieve it by licking or chewing his foot. A dog’s paw pads are not immune to picking up rocks, thorns or other foreign objects they step on. They can cut their pads while romping in the backyard or playing at a dog park, and a hot sidewalk or road can burn their pads. Snow, road salt and ice can also build up between their pads during the winter months. Canines will also engage in this behavior due to other, more serious causes, such as interdigital cysts (lumps between their toes), tumors and other cancers, and autoimmune diseases of the nail beds or paw pads.
4. A Parasitic Microbe
A type of mange called Demodicosis mange (Red Mange) is a microscopic mite that affects one or more of a dog’s feet, and it’s a common skin disease in dogs. Yeast infection and flea allergies will also cause a dog to chew his feet.
Though there are many different reasons a dog may lick his paw, its always important to see a veterinarian if the problem persists.