Cancer is a term that is used for a variety of genetic diseases that change the way cells grow and function. These cancerous cells cause different symptoms depending on the organ system they affect, such as lethargy, loss of appetite, fever, enlarged lymph nodes, nausea, can even lead to sudden death. Although these symptoms indicate that something is not right, it is important to know that their appearance doesn’t necessarily mean the dog has cancer. These symptoms can also occur in some other diseases. That is why it is important to contact a veterinarian if you notice some of the symptoms listed in this article in your dog; the correct diagnosis can be determined only through detailed examination.
In this article, you will learn more about the most common types of dog cancer, the symptoms of each, diagnosis and possible treatment, and the difference between benign and malignant tumors.
Signs of Cancer in Dogs
Everyone wants to take the best possible care of their dogs and to make sure they live happily and for as long as possible. However, with old age, new risks arise. It is estimated that as much as 30% of all domestic dogs will develop cancer at some point throughout their life, just like humans.1Gibealult, S. (2017, October 09). Cancer in Senior Dogs – Signs and Symptoms to Watch For. AKC.
Early detection of cancer increases the chances of more successful treatment. Here are some of the symptoms that indicate that a dog may have cancer.
- Weird lumps or bumps: Lumps or bumps that persist or change in their shape or texture could be a sign of cancer. They should be checked out by your veterinarian as soon as possible. The easiest way to detect any lumps is by petting your dog.
- Enlarged lymph nodes: Lymph nodes are located in many places on the dog’s body, but the ones you can easily find are the lymph nodes behind the jaw (submandibular lymph nodes) and the lymph nodes behind the knee (popliteal lymph nodes). If they are enlarged, it could be a sign of infection or a common cancer called lymphoma. If you notice that your dog’s lymph nodes are bigger than usual, you should take your dog to the veterinarian as soon as possible.
- Loss of appetite and weight loss: We all know how much our pets love their treats. If your dog is not on a diet and is still losing weight, you should take him to the vet. This is not a definitive symptom of cancer, but it can imply that something is wrong. Chronic weight loss appears in cancer patients.
- Persistent nausea or diarrhea: Unusual vomiting or diarrhea with no apparent cause could be a sign of gastrointestinal tumors. Other, less-lethal diseases can also have these symptoms, and only a veterinarian can determine if cancer is the cause or not.
- Strange bad smell: If you notice your dog doesn’t have the same odor he used to have, or if he has a worse odor than usual, that could be a sign of a tumor. Usually, tumors in the mouth, nose, anus, or vagina can cause your dog to have a bad odor.
- Bleeding: Has your dog been bleeding from his nose, mouth, or anus, but you cannot find any trauma that caused it? Unexplained bleeding could also be a sign of cancer, and you should get your dog checked out as soon as possible.
More about the symptoms of the most common cancers in dogs will be explained in detail later on.
Dog Skin Cancer – Types and Signs
Skin cancers are one of the most common cancers that can affect your dog, not only because the skin is the largest organ, but also because it is the most exposed organ to environmental factors, sun radiation, different chemicals, and viruses. What most owners usually notice first is the appearance of a lump. Luckily, 60 to 80% of skin tumors are benign and can be cured early with surgical removal.25 Types of Skin Cancer in Dogs. VNC State Veterinary Hospital. Retrieved 13 April 2021. However, if the tumor is malignant, further treatment may be required.
There are indications that genetics is the number one factor for developing skin cancer. Other factors such as a sunburn, exposure to different chemicals, and environmental factors can also lead to skin cancer. Dogs with no fur or with light skin have a higher chance of having a skin tumor due to sun radiation.
Here are some of the most common skin cancers in dogs.
Mast Cell Cancer in Dogs
Mast cells are cells of the immune system. They contain bubbles of a chemical called histamine, which is usually involved in allergic reactions. Mast cells react with antigens in our body, bursting and releasing histamine and causing an allergic reaction. A large portion of mast cells is found in the skin, so mast cell cancer can appear anywhere on a dog’s body.
The symptoms of mast cell cancer involve irritation and itching, as well as stomach ulcers, as a result of histamine release. The cause for this disease is idiopathic (unknown).
These tumors are more likely to be found in the following breeds:
- Golden Retrievers
- Shar Pei
- Boston Terriers
- Labrador Retrievers
Diagnosis of mast cell tumor is done by using a syringe and a needle and taking out the content of the tumor. A veterinarian should examine the content, or send it for further lab examination.
Mast cell tumors are usually graded, from low-grade to high-grade tumors. Low-grade mast cell tumors are usually cured with surgical removal, but high-grade tumors sometimes need further treatment, as they can spread to distant parts of the body and the internal organs.
Dog Squamous Cell Carcinoma
In most cases, dog squamous cell carcinoma starts as a small lump or a minor abrasion, but it can quickly damage the surrounding tissue, which makes surgical removal of the tumor very hard and in some cases even impossible.
One of the leading causes of squamous cell carcinoma is exposure to the sun. This type of skin cancer is likely to be found in the following breeds:
- Bull Terriers
- Basset Hounds
- Standard Poodles
Incompletely removed tumors need to be exposed to radiation therapy to prevent them from growing again. Dogs that spend a lot of time outdoors and dogs with light skin and a thin coat are at a higher risk of squamous cell carcinoma.
Fibrosarcoma in Dogs
Fibrosarcoma is a tumor of the connective tissue in the skin and beneath the skin. It is caused by a variety of factors, such as genetics and environmental factors. It is considered to be a slow-growing tumor, except in some rare cases, where fibrosarcoma can affect the jaw bone or the leg bone, it can grow rapidly.
The following breeds have a higher risk of developing this disease:
- Doberman Pinschers
- Golden Retrievers
- Brittany Spaniels
- Irish Wolfhounds
- Gordon Setters
Since these tumors are most commonly found on the limbs, the symptoms may include the following:
- Difficulty walking and getting up
- Swelling of the area
- Loss of appetite
Fibrosarcomas are usually diagnosed by fine-needle aspiration. The content from the aspiration is then examined and the tumor is graded. The usual treatment for this tumor is surgical removal, but it can sometimes be impossible because of the location and the invasive nature of the tumor.
Malignant Melanoma in Dogs
Malignant melanoma is a fast-growing skin tumor, which can appear as small, dark-pigmented masses, or in some cases, as large, wrinkled tumors. They can grow rapidly and quickly spread to nearby lymph nodes or to the lungs. Malignant melanoma occurs less frequently than benign melanoma. Some breeds, like Miniature and Standard Schnauzers, are at higher risk of malignant melanoma cancer.
The type of most of these tumors is determined when they are removed. Benign tumors are cured with surgical removal, but malignant tumors may require further treatment, such as chemotherapy.
Not every little bump you feel on your dog is a malignant tumor. Actually, it’s more commonly benign. Those benign tumors are in most cases better left untreated, unless they make your dog’s life harder, for example, when he walks or sits. However, you should consult with your veterinarian as soon as you notice something unusual.
Bone Cancer (Osteosarcoma) in Dogs
Osteosarcoma is a type of cancer that mostly affects long bones, although it can also affect the jaw bone, pelvis, or hips. It can also affect other organs and tissue such as the liver, spleen, kidney, and mammary gland (extraskeletal osteosarcoma). Osteosarcoma or bone cancer can be caused by a variety of factors, such as genetics, environmental factors, and extra weight. Even the metal pins used in some orthopedic surgery can lead to osteosarcoma.
Large dogs are more susceptible to this type of cancer, as well as the following breeds:
- Labrador Retriever
- German Shepherd
- Great Dane
- The Great Pyrenees
- Irish Wolfhound
- Doberman Pinscher
- Irish Setter
- Saint Bernard
Dogs that don’t receive any treatment have a life expectancy of 2 to 4 months, and dogs that undergo chemotherapy and surgery have a life expectancy of 10 to 12 months.3Culp, W. T., Olea-Popelka, F., Sefton, J., Aldridge, C. F., Withrow, S. J., Lafferty, M. H., Rebhun, R. B., Kent, M. S., & Ehrhart, N. (2014). Evaluation of outcome and prognostic factors for dogs living greater than one year after diagnosis of osteosarcoma: 90 cases (1997-2008). Journal of the American Veterinary Medical Association, 245(10), 1141–1146. https://doi.org/10.2460/javma.245.10.1141
Symptoms of Bone Cancer in Dogs
Osteosarcoma can cause great damage to the bone, and it can be very painful. Symptoms may include lethargy, loss of appetite, and if osteosarcoma has affected a limb, it can cause difficulty while walking, swelling in the area, and even possible bone fractures.
Diagnosis and Treatment of Bone Cancer in Dogs
Dogs affected by osteosarcoma will usually have lameness of one limb, followed by swelling and the dog’s inability to run or even walk. The first step in diagnosing bone cancer in dogs is taking X-rays of the region suspected to be affected by cancer. If a dog has bone cancer, the affected bone will look moth-eaten on the X-ray, because the osteosarcoma is destroying the bone tissue.
Further diagnostics could be done by fine-needle aspiration. The treatment will be based on how much cancer has spread. If it is still localized, amputation is the only surgical option and provides a good prognosis. If the cancer has spread, amputation and radiation therapy are required.
Breast Cancer in Dogs
Breast cancer is a result of a fast replication of the cells in breast tissue. These mammary tumors can be diagnosed as benign or malignant. In dogs, more than half of these tumors are malignant. The cause of breast cancer, among other things, is believed to be the hormone progesterone, which stimulates breast cells to replicate.
Dogs that are spayed have a lot lower chance of getting breast cancer. Dogs spayed before their first heat have a risk of only 0.5%, while after their first or second heat, the risk goes up to 8 – 26%. Some breeds like Yorkshire Terriers, English Setters, Boxers, Cocker Spaniels, Dachshunds, Poodles, Brittany Spaniels, and Chihuahuas have a higher risk of having breast cancer.4Stoewen, D., Pinard, C. Malignant Mammary Tumors in Dogs. VCA Hospitals. Retrieved 14 April 2021.
Signs of Breast Cancer in Dogs
If a dog has breast cancer, a veterinarian should be able to find one or more palpable masses under the skin of the abdomen during a clinical examination. The shape and the size of the masses may vary, but the tumor can get very big, causing the mammary gland to discharge. The skin above the tumor can also open, causing bleeding. If the tumor has spread to other organs, other symptoms such as lethargy, chronic weight loss, and generally bad health may appear.
Diagnosis and Treatment of Breast Cancer in Dogs
The diagnosis of breast cancer is fairly simple. With firm nodular tumors, another examination is required to determine whether they are benign or malignant. A veterinarian may use fine-needle aspiration and evaluate the content under a microscope. In some cases, the whole tumor needs to be taken out and examined by a veterinary pathologist.
Treatment for benign breast tumors is usually just surgical removal, but for malignant cases that may have spread to other areas, other treatments, such as chemotherapy, may be required.
About 50% of dogs with malignant mammary tumors have a good prognosis, even after only going through surgery.5Canine Mammary Tumors. VNC State Veterinary Hospital. Retrieved 14 April 2021.
Dog Mouth Cancer (Oral Cancer)
Oral cancer in dogs usually affects older dogs. Dogs with dark pigmented tongues and gums, such as Chow Chows, are also at a higher risk. There are two types of oral tumors: benign and malignant. A benign tumor mostly has marked edges and is easily cured by surgical removal, and it does not spread to nearby organs or tissue. However, malignant oral tumors are more common than benign, and there are three types: squamous cell carcinoma, fibrosarcoma, and malignant melanoma.
Signs of Mouth Cancer in Dogs
It is important to know the signs of oral cancer in dogs so you can detect it early and have a better chance of successful treatment. The signs will vary depending on the location, growth, and type of the tumor, as well as how far and if it spread. The signs typically include:
- Pain (especially noticeable when eating)
- Bad breath (halitosis)
- Loss of teeth
- Enlarged lymph nodes
- Loss of appetite
- Visible mass in the mouth
Diagnosis and Treatment of Mouth Cancer in Dogs
Mouth tumors are diagnosed by using a needle and a syringe and by taking a sample of the cells from the tumor (FNA – fine needle aspiration). That sample is then examined by a veterinary pathologist. However, results from FNA may not be enough for a final diagnosis, so a biopsy is required. The biopsy can also help determine what type of a tumor it is, and it can help with further treatment.
Surgical removal is the most common treatment for most oral tumors. Prior to any treatment, CT scans of the neck/head are usually performed, to determine the extent of damage caused by the tumor, and for planning further surgical procedures. The veterinary surgeon may remove local lymph nodes if they are affected, or even as a preventive measure.
Liver Cancer in Dogs
If a dog is diagnosed with liver cancer, it can either mean that the cancer started in the liver, or that the dog has another type of metastatic cancer that has spread to the liver.
The most common type of liver cancer in dogs is hepatocellular carcinoma, but there are others, such as a neuroendocrine tumor, mesenchymal tumor (sarcoma), and bile duct carcinoma.
Liver cancer most often affects older dogs, but that does not mean it can’t occur in younger dogs too. In most cases, there is no clear cause of this cancer.
Dogs with a history of chronic liver inflammation or liver damage are more prone to liver cancer. So far, no breeds have been named as having a predisposition to liver cancer.
Symptoms of Liver Cancer in Dogs
Unfortunately, the symptoms of liver cancer stay hidden until a later stage of the disease, so prevention and early detection are almost minimal. Some of the symptoms include vomiting, diarrhea, swollen abdomen, lethargy, weakness, yellowness of the skin (jaundice), weight loss, excessive thirst (polydipsia).
Diagnosis and Treatment of Liver Cancer in Dogs
Liver cancer can be complicated to diagnose. A chemical blood profile, a complete blood count, and some more laboratory tests are required to look for signs of liver damage or dysfunction.
Radiographs and ultrasounds may be needed to confirm the size of the tumor and to look if it has spread to other organs as well. If any of these tests are not conclusive, a sample of the tumor will be taken by fine-needle aspiration or biopsy. That will allow the veterinarian to diagnose what type of tumor it is and to come up with the best treatment.
In most cases, surgical removal is the best treatment for liver tumors. Prognosis depends on a variety of factors, such as the dog’s overall health, the extent of tissue involvement, treatment options, and the success of the surgery.
Lung Cancer in Dogs
There are two types of lung cancer in dogs: primary and secondary (metastatic). Primary lung cancer is a tumor that starts in the lung, and metastatic lung cancer is a tumor that started somewhere else in the dog’s body but spread to the lung by the bloodstream.
The exact cause for lung cancer is still unknown, but some factors, such as genetics, environmental factors, living in urban areas with high levels of pollution, inhaling smoke, or other toxic gases, may contribute to the development the illness. Some breeds like Golden Retrievers, Irish Setters, Australian Shepherds, Boxers, Doberman Pinschers, and Bernese Mountain dogs are at a higher risk of developing lung cancer.
Symptoms of Lung Cancer in Dogs
Some of the symptoms include the following:
- Abdominal and chest pain
- Weight loss
- Loss of appetite
- Unwillingness to walk or run
- Coughing up blood
- Fast and labored breathing
- Shortness of breath
Even though most of the symptoms won’t appear until later stages of illness, it’s important to try to spot symptoms of lung cancer early so the chance for a successful treatment is higher.
Diagnosis and Treatment of Lung Cancer in Dogs
Some lung tumors are diagnosed accidentally when dogs are brought in for X-rays of some part of the body. That’s why veterinarians recommend yearly X-rays for senior dogs.
A veterinarian will most likely take an X-ray of the dog’s chest if it has symptoms of respiratory problems.
If X-ray results are not conclusive, a CT scan may be required. Also, lung cancer can be diagnosed by fine-needle aspiration or a lung tissue biopsy.
Treatment of lung cancer in dogs depends on the stage of the illness, as well as the dog’s overall health. If the dog is healthy enough for surgery, a surgeon will remove the tumor from the lung and get a chance to explore the dog’s chest to see if the cancer has spread.
After surgery, if cancer has spread, or the surgeon was not able to remove some parts of the tumor, radiation and chemotherapy will be required. The same goes for dogs that were not healthy enough to undergo surgery.
Hemangiosarcoma in Dogs
Hemangiosarcoma is a cancer of the blood vessels, and the primary sites for this cancer are the spleen, the heart, and the skin. This cancer affects blood-rich areas the most, and that’s why it is classified as one of the most dangerous cancers. Even though the exact cause is not known, it is believed that environmental factors and genetics play a role.
Hemangiosarcoma can affect dogs of any age, but it is more commonly found on older dogs, and at-risk breeds such as Golden Retrievers, Labrador Retrievers, and Portuguese Water Dogs.
Symptoms of Hemangiosarcoma in Dogs
In the early stages of the disease, the tumor may not be visible, so it’s important to know the clinical signs of hemangiosarcoma for a higher chance of diagnosing the tumor early. Some of the symptoms may include the following:
- Abdominal swelling
- Pale colored gums
- Difficulty breathing
- Lack of desire to play
- Visible bleeding (sometimes nosebleeds)
Diagnosis and Treatment of Hemangiosarcoma in Dogs
Diagnosis of hemangiosarcoma can sometimes be difficult. It starts with a physical examination of the dog, checking for pale gums and abdominal swelling, among other things. The next step is performing x-rays of the abdominal region and checking for tumorous masses to see if any other organs are affected by the tumor. Blood tests, urinalysis, thoracic radiography, and ultrasonography may also be required. A definitive diagnosis of hemangiosarcoma is done by biopsy.
The treatment of hemangiosarcoma depends on the location of the tumor. If the tumor is located in the skin, surgical removal is the best treatment. If the surgeon was not able to remove the tumor completely, or if he suspects that some cancerous cells have spread to the nearby area, chemotherapy may be required. If the tumor is located in the internal organs of the dog, the standard treatment becomes a combination of surgery and chemotherapy.
Stomach Cancer in Dogs
Stomach cancer can be a devastating disease, primarily because in most cases, it shows no symptoms until later stages. The exact cause for this disease is still unknown, but it is more common in older male dogs of 9+ years. Some at-risk breeds are Chow Chows, Staffordshire Bull Terriers, Rough Collies, and Belgian Shepherds.6Canine Stomach Cancer: Symptoms, Treatments and Prognosis. Blue Pearl Vet. Retrieved 14 April 2021.
Symptoms of Stomach Cancer in Dogs
Although it is difficult to notice the symptoms of stomach cancer in dogs early on, it is necessary to pay attention to certain signs such as vomiting and black or coffee-colored stool. Other symptoms may include weight loss, loss of appetite, abdominal pain, excessive salivation, and nausea. In most cases, the symptoms become pronounced when the disease reaches an advanced stage.
Diagnosis and Treatment of Stomach Cancer in Dogs
Diagnosis of stomach cancer in dogs can be started based on past information, such as excessive vomiting, weight loss, and loss of appetite. An X-ray of the abdominal region may be required, as well as an endoscopy (inserting a flexible tube with a small camera on top and passing it through into the dog’s stomach). If a tumor is seen, a biopsy may be required, and it can be done during the endoscopy.
The best treatment option is a combination of surgery, used to remove affected parts of the stomach, with radiation and chemotherapy.
Dog Nose Cancer (Nasal Cancer)
Dog nasal cancer is a local aggressive cancer, which means that it does not spread fast, but it causes destruction of the nasal cavity tissue and bone. A nasal tumor begins with the fast uncontrolled growth of the cells that line the nasal cavity. The exact cause for this cancer is unknown, but environmental and genetic factors, living in urban environments, and inhaling secondhand cigarette smoke can play a huge role.7Buzhardt, L. The Effects of Second-hand Smoke on Pets. VCA Hospitals. Retrieved 15 April 2021.
Symptoms of Nose Cancer in Dogs
Most of the symptoms of nasal cancer can stay hidden until later stages of the disease.
Some symptoms may include nasal discharge (mucous, bloody, or pus), sudden snoring, excessive sneezing, and facial deformity.
Diagnosis and Treatment of Nose Cancer in Dogs
Diagnosis of dog nasal cancer can require several steps, including a full physical examination to look for facial abnormalities, blood tests, rhinoscopy, CT scan, nasal radiographs, tissue biopsy, and fine-needle aspiration.
Due to the location of the tumor, surgery is often too difficult to perform, so radiation therapy is the preferred treatment for dog nasal cancer.
Prostate Cancer in Dogs
The most commonly diagnosed prostate cancer in dogs is prostatic adenocarcinoma. This cancer can be highly aggressive and in most cases, it metastasizes to other parts of the body before it is even diagnosed. It can affect both neutered and intact male dogs of any breed, although it is more commonly found in large breeds, such as Doberman Pinschers, Airedale Terriers, and German Shorthaired Pointers, and in older dogs around 10 years of age.
Some of the other breeds at risk of developing prostate cancer are listed below:
- Miniature Poodle
- Scottish Terrier
Signs of Prostate Cancer in Dogs
Because of the location of the tumor, the most common signs of prostate cancer in dogs include the following:
- Inability to urinate
- Blood in the urine
- Excessive drinking
- Loss of appetite
- Weight loss
- Change in posture due to pain in the lower back or the abdomen
Because the colon can be affected too, problems such as slower bowel movements may appear.
Diagnosis and Treatment of Prostate Cancer in Dogs
A veterinarian may be able to find an enlarged prostate during a physical examination, which can be a sign of prostate cancer. With this discovery, further examination like X-rays, blood work, catheterization (insertion of a catheter through the urethra to the prostate), and using an ultrasound to perform fine-needle aspiration may be required.
For the treatment of prostate cancer in dogs, surgery is sometimes difficult to perform due to the chance of damaging the urethra. Other options like radion therapy or chemotherapy may be pursued.
Testicular Cancer in Dogs
This type of cancer is thought to be the most common in older, intact male dogs. There are three types of testicular cancer:
- Interstitial cell tumors
- Sertoli cell tumors
Although the exact cause is unknown, there are indications that some environmental and genetic factors play a role. Certain breeds like the Maltese, Afghan Hounds, Boxers, German Shepherds, Collies, and Weimaraners are at a higher risk of developing testicular cancer.
Signs of Testicular Cancer in Dogs
Testicular cancer sometimes doesn’t have any obvious clinical signs, except for masses in the scrotum region or generalized swelling of the scrotum (testicles).
Sertoli tumors can produce estrogen and cause hyperestrogenism (higher levels of estrogen), which results in signs of feminization; enlarged nipples and mammary glands, hair loss, and hyperpigmentation.
In cases where testicular cancer has spread to nearby organs, then the symptoms will change according to the organ system affected, such as weight loss, lethargy, loss of appetite, or vomiting.
Diagnosis and Treatment of Testicular Cancer in Dogs
A veterinarian may be able to find an abnormal testicle during a physical examination. With that in mind, a veterinarian can do an abdominal ultrasound to look for abnormal testicular masses. Further diagnostic testing may include fine-needle aspiration and histopathology.
The most commonly recommended treatment for testicular cancer is the surgical removal of the testicles. If the tumor has spread to other parts of the body, chemotherapy or radiation therapy can be the next step in the treatment of testicular cancer in dogs.
Bladder Cancer in Dogs
The exact cause for bladder cancer in dogs is unknown. There are indications that genetic predisposition and environmental factors play a huge role. Compared to cancer in other locations in the body, bladder cancer is unusual in dogs; it makes up for 2% of cancer cases in all dogs.8Knapp, W. Deborah. Canine Bladder Cancer. College of Veterinary Medicine – Purdue University. Retreieved 15 April 2021.
There are two types of dog bladder cancer:
- urothelial carcinoma (UC)
- transitional cell carcinoma (TCC)
The most common type of bladder cancer in dogs is TTC. TCC is thought to be a deadly form of cancer because of how quickly it metastasizes. This means that cells start growing in the bladder, but soon start spreading to the lower parts of the urinary tract of the dog. Then after spreading to nearby lymph nodes, cancer spreads to other parts of the body through lymph nodes.
Some breeds like Scottish Terriers, Shetland Sheepdogs, Wire Hair Fox Terriers, West Highland White Terriers, and Beagles are at higher risk of bladder cancer.
Symptoms of Bladder Cancer in Dogs
It’s important to notice the symptoms early, so the chance for successful treatment is higher. The symptoms of dog TCC may include the following:
- Painful urination
- Repeated frequent attempts of urinating
- Blood in the urine
However, these are similar symptoms of a urinary tract infection, so these symptoms alone don’t mean the dog has TCC. In some rare cases when TCC spreads to nearby bones, dogs experience lameness.
Diagnosis and Treatment of Bladder Cancer in Dogs
Several other conditions such as bladder infection, bladder inflammation, or bladder stones can cause similar symptoms to TCC. These conditions can also create “masses,” which can be seen on ultrasound or radiographs and be mistaken for TCC. The best diagnosis of bladder cancer is tissue biopsy, which is mostly done by surgery.
The treatment of bladder cancer will depend on the dog’s overall health and the progression of the disease. Some of the treatment options are the following:
- Radiation therapy
- Use of NSAIDs (non-steroidal anti-inflammatory drugs)
- Surgical removal (surgery is not always an option because sometimes the tumor can be located in an area where surgery could create even bigger problems, like the urethra)
Lymphoma Cancer in Dogs
Lymphoma is a wide term for a group of cancers that originate from lymphocytes—cells that are involved in the immune response of the body. The lymph nodes, the spleen, and bone marrow are the organs that are most concentrated with lymphocytes. These organs tend to be the most affected by lymphoma.
The exact cause of lymphoma cancer is still unknown, but some breeds like Scottish Terriers, Bullmastiffs, Golden Retrievers, Boxers, Bulldogs, and Airedale Terriers have a higher risk of developing lymphoma.
Symptoms of Lymphoma Cancer in Dogs
The symptoms of lymphoma cancer in dogs can change depending on which part of the body the lymphoma has affected, but some of the symptoms may include the following:
- Enlarged lymph nodes
- Loss of appetite
- Weight loss
- Shortness of breath
- Excessive urination
Diagnosis and Treatment of Lymphoma Cancer in Dogs
The most common diagnostic tool in dog lymphoma is fine-needle aspiration of the affected organ. The sample is then taken for microscopic examination, and a veterinarian will look for signs of cancer cells. If this test is not conclusive, a biopsy of the lymph node may be required. Blood tests also may be required.
The treatment of lymphoma cancer in dogs depends on how far the disease has spread. The most common treatment for dog lymphoma is chemotherapy. In some cases, surgery or radiation therapy is required.
Early detection of cancer in dogs increases the chances of successful treatment, so it is important that you take your dog for veterinary check-ups at least once a year. If you have an older dog or a dog breed that has a higher risk of developing cancer, it would be wise to visit the veterinarian at least once every 6 months and that you are informed about possible symptoms of cancer so you can detect the disease as early as possible.
Since there are different types of cancer that can develop in dogs, symptoms can vary depending on the type of disease. Some of the major symptoms of cancer in dogs include unexplained bleeding, strange odor, persistent diarrhea or nausea, abnormal discharge from any body opening, loss of appetite and weight loss, weird bumps or lumps, enlarged lymph nodes, lethargy, persistent or abnormal swelling of a certain area, difficulty breathing, defecating, or urinating.
These symptoms can also occur due to other, less severe diseases, so it doesn’t necessarily mean that they are cancer-related. Even if they are, it could be benign. Don’t jump to any conclusions, and take your dog for an examination, as only a vet can determine the right cause.
All tumors are defined by an abnormal growth of cells in our body. Not every tumor has to be malignant; in fact, according to research, as much as 80% of all tumors are benign. Benign tumors consist of cells that resemble the normal cells of the organ in which they are found. Even though benign tumors are usually harmless, their location can present a difficulty for the dog, which then requires surgical removal.
The type of cancer treatment will depend on what type of cancer has occurred, but also on some other factors, such as the dog’s age, his general health, the stage of cancer, etc.
Treatment options for both malignant and benign tumors may include surgery, chemotherapy, and radiation therapy. Surgery is used to remove as much of the tumor as possible, and it is usually a part of any cancer treatment whenever possible. Sometimes surgery is the only option for cancer treatment, but in many cases, it is often used before or after radiation therapy or chemotherapy.
In some cases, for example in cases of dog nose cancer, surgery may not be possible, because of the localization of the tumor. If and when surgery is not possible, radiation therapy may be suggested by your veterinary oncologist. In some cases, if cancer has spread to different parts of the body, chemotherapy may be the preferred option, or a combination of chemotherapy and radiation therapy.
Since with most cancers, the cause is unknown, it’s not possible to suggest any specific preventive measures. However, there are some environmental influences that can contribute to the development of cancer, such as exposure to cigarette smoke, pesticides, herbicides, and other toxins.9Buzhardt, L. The Effects of Second-hand Smoke on Pets. VCA Hospitals. Retrieved 15 April 2021. To reduce the risk, keep the dog away from the mentioned harmful substances, maintain regular check-ups, and spay or neuter the dog at an appropriate age.