Cancer in dogs | Symptoms and treatment | Blue cross (2023)

Just like humans, dogs are prone to cancer, especially as they get older. By far the most commonly affected areas are the skin, digestive system and chest, which is most common in bitches.

The vet says my dog ​​has a tumor - is it cancer?

The language surrounding cancer can be confusing and the definitions difficult. Tumors (also called growths) can be cancerous or non-cancerous, depending on what they do in the body.

A tumor is an uncontrolled growth of microscopic body components (known as cells). This causes disease, often by forming knots in the body's organs and disrupting their normal arrangement so that they cannot function properly. Some tumors remain in the tissue where they originated; they are generally described as "benign" and are not actually cancer. Others may spread throughout the body; they are called "malignant" and are called neoplasms.

What causes cancer? Is there anything I could have done to prevent this?

There seem to be several things that increase the likelihood of developing cancer, and statistically certain breeds seem to be more susceptible to certain types of cancer. It is known that neutering bitches before the age of two reduces the risk of mammary cancer, but the direct connection with diet and lifestyle has not yet been fully investigated in dogs.

What are the symptoms?

They can also be symptoms of many other diseases, so it pays to take your pet to the vet. Although tumors can grow slowly, they can sometimes cause sudden symptoms of the disease.

What happens then?

Usually, a veterinarian cannot tell if a pet has cancer just by looking at it. Blood tests to detect cancer are still in their infancy. Additional tests, such as blood tests and X-rays, are often required.

An ultrasound or MRI may be suggested. They can help detect whether the cancer has spread to other areas of the body - a process vets call "staging". They can also indicate your pet's overall health, which affects his ability to withstand treatment.

A biopsy (taking a small sample for examination under a microscope) can help identify the tumor and see if it is cancerous. Achieving a definitive diagnosis can sometimes be difficult; for example, biopsies do not always contain sufficient material of good quality when examined under a microscope.

What is the treatment?

There are many types of cancer, and treatments are available for non-cancerous tumors and even for some malignant tumors. For an isolated lump that has not spread throughout the body, surgery may provide a cure. But it depends on where the tumor grows. Even a benign tumor in an area such as the brain cannot be easily removed in animals. If the cancer has spread inward, treatment options depend on the exact type of cancer and the extent to which it has spread. However, quality of life is important, and if your pet is in severe, unrelenting pain, your vet will likely encourage you to euthanize.

There are three basic types of treatment - surgery, chemotherapy and radiation therapy. Several other new therapies are sometimes available, such as photodynamic therapy or immunotherapy. Some forms of treatment require frequent visits to your own veterinarian or specialists, and it may be important that you receive treatment at certain intervals.

Surgery is often chosen for skin tumors or internal growths that look different. A lump removed during surgery usually needs analysis to determine if it is likely to have spread. Occasionally, for internal growths where the size of the tumor is the cause of the disease, surgery can relieve symptoms, but the risk of recurrence remains.

Chemotherapy is suitable for several types of cancer. Veterinary chemotherapy usually has few or no side effects because the doses used are lower than those used in humans. Unfortunately, it usually does not cure cancer - the goal is to slow down the cancer process and relieve symptoms.

Chemotherapy is sometimes given after surgery if the entire cancer has not been removed to try to slow down recurrence. It is also used for large tumors that cannot be removed with surgery, such as tumors that affect white blood cells (leukemia). Some types of chemotherapy may be available from your vet; others are carried out only by experts.

Regular visits to the vet for treatment are usually necessary, and sedation may be required during treatment. Tablets may also be needed. Possible side effects of chemotherapy include a short period of decreased appetite, vomiting, or diarrhea. Sometimes medications cause the number of white blood cells to drop, which can make infection more likely, so blood tests are usually done during treatment to check for this.

Radiation therapy is only available in a few specialized centers. Again, it usually does not heal and often requires regular visits for a period of time. Since the animal must be completely still during the procedure, a short general anesthesia is given for each procedure.

Is it fair to treat a pet for cancer?

Veterinarians are aware of the importance of keeping animals pain-free, and current pain relievers are very effective. Unfortunately, for all animals with terminal cancer, there will come a time when they will suffer and lose their quality of life. You and your vet should work together to recognize when this is happening and then choose euthanasia. However, most veterinarians agree that a healthy, happy pet should not be euthanized, even if the dog is suffering from an incurable disease.

How long will my pet live?

This is something that cannot be predicted with certainty. The type of cancer and its stage at diagnosis give an idea, and for some types of cancer there are more specialized tests that help determine the prognosis. But like all other diseases, cancer does not necessarily follow a steady course. Unfortunately, there can be a sudden deterioration.

Specific types of tumors and tumors

The information below is not exhaustive, but it gives you a general idea of ​​how to treat the different types of cancer commonly found in dogs.

Hudtumorer

Many skin nodules are benign and can be surgically removed. Occasionally, there may be obstacles to removal if the lump is very large or is in an area where it is difficult to repair the surgical wound. This is something your vet will talk about. Unfortunately, there are some types of cancer that recur in the same place, and some that spread to other places in the body. Biopsies can be useful because if an aggressive tumor is identified, surgical removal of a larger area of ​​skin can reduce the likelihood of recurrence or spread.

Breast tumors

Dogs have five breasts on each side of the abdomen, visible as two rows of nipples, and bumps may be present in one or more of them. About half of these tumors are benign, while the rest are malignant. The options for surgery are to remove the lump itself or to remove some or all of the remaining breast tissue. Removing more tissue does not seem to prevent the tumor from spreading inward. They often spread to the lungs, so a chest x-ray is indicated before surgery, although early spread may not be visible. Spaying a bitch during or after mammary surgery can reduce the risk of recurrence.

Leukemia or lymphoma

It is a cancer that affects the white blood cells. A special type of white blood cell, called lymphocytes, is usually involved. Lymphocytes circulate in the blood and also in the lymphatic system, which is a system of vessels and centers (swellings called lymph nodes are often called glands). This is where the body checks for infections and other foreign bodies that might try to enter the system.

When lymphocytes become cancerous, their number increases uncontrollably. The number of lymphocytes in the blood can increase, but often the lymphocytes sit in one place and multiply. This can cause one or more lymph nodes to enlarge and form lumps in the neck or other parts of the body, or it can affect internal organs such as the liver, spleen or intestines. Cancerous lymphocytes can easily spread to other parts of the body through the bloodstream or lymphatic system (the tubes that connect the lymph nodes).

Because lymphoma is usually widespread, surgery alone is usually not appropriate. If untreated, the median survival time from diagnosis is approximately two months. This can be extended with chemotherapy (in some cases to 12 months or sometimes longer), although unfortunately not all lymphomas respond successfully. Survival expectations are something you should discuss with your vet as they vary depending on which part of the body is affected.

Warning signs that your pet may be in pain

• Changes in behavior
• Lost appetite
• Difficulty moving and walking
• Anxiety, difficulty in feeling comfortable
• Your pet may appear withdrawn or tense
• Occasional wagging of the tail does not mean that the animal is not in pain
• Behavioral improvement with pain medication (give only pain medication prescribed by your vet)