Chemotherapy Treatment for Dogs

February 8, 2019
If your pet has cancer, you'll probably want to try every single option so he'll recover as soon as possible. One of these options is chemotherapy for dogs.

If your dog is diagnosed with cancer, you’ll want to make sure that he suffers as little as possible from the onslaught of this disease. Chemotherapy treatment for dogs is an option that the veterinarian might suggest. Also, it’s usually less aggressive than the treatment that humans receive. Here’s more about it.

The most common types of tumors in dogs

Lymphosarcoma and mastocytoma are the most common cancers that dogs can suffer from. They’re also the ones that are most often treated with chemotherapy. 

The first, lymphoma, occurs when there’s a malignant lymphocyte neoplasm that originated in an organ. These include:

  • Lymph nodes
  • The liver
  • The spleen
  • Other organs with lymphoid tissue
A dog getting chemotherapy.

This type of disease has nothing to do with lymphoid leukemias since those originate in the bone marrow.

As for mastocytoma, it’s the most common skin cancer in dogs, but it can also spread to the internal organs. In most cases, surgical treatment combined with pharmacological treatment will allow the affected animal to maintain a good quality of life.

Chemotherapy for dogs with cancer is an option that veterinarians may suggest for some cases. It’s usually less aggressive than the chemotherapy that humans receive. 

Chemotherapy treatment for dogs, an option to treat cancer

Chemotherapy treatment for dogs is an exceptional treatment that could cure the animal; it’s really the only treatment that’s available.

The treatment is more effective when the tumors are small or when they have a high proliferation capacity. That’s because they’ll have a high number of rapidly dividing cells, which are the ones that chemotherapy destroys.

When the tumor has grown too large, the cancer cells will stay at rest. Because of this, the chemotherapy will be less effective.

Questions to consider before deciding on chemotherapy treatment for dogs

After diagnosing your pet with cancer, the vet will tell you the different treatment options.

If chemotherapy is one of these options, then the vet will need to thoroughly evaluate your pet’s health before starting the treatment.

For example, it’s not recommended for animals with advanced stages of cancer, with metastasis and with any deterioration in their vital organs (kidney, liver, etc.). In these cases, instead of improving his quality of life, it will actually further deteriorate his health.

Chemotherapy uses, depending on the type of cancer

Depending on the type of cancer your pet is diagnosed with, the vet will evaluate the best way to administer the chemotherapy treatment.

If he has tumors in his lymphatic system, chemotherapy is the only option since the vet won’t be able to operate on neoplasms that are spread throughout his entire body.

Once the vet locates the tumors, he can take different measures:

  • If they result in metastases: First, he’ll operate on the tumor. Then, he’ll apply the chemotherapy as a way of delaying the appearance of malignant cells in other organs.
  • If he cannot completely remove them through surgery: Chemotherapy can destroy the malignant cells that remain in the body.
  • If the tumors are too large to be removed via surgery: They are treated with chemotherapy to try to stop the growth and, if possible, to reduce the size.

Side effects of chemotherapy for dogs

A sad looking dog.

According to statistics, less than 5 percent of dogs that receive chemotherapy suffer serious side effects.

In most animals, if there are any side effects, they are just mild or transient. For example:

  • Loss of appetite
  • Sickness
  • Vomiting
  • Diarrhea
  • Weakened defenses

Whatever the situation, the veterinarian has different tools to prevent or stop the side effects that chemotherapy for dogs can cause. 

  • Dhaliwal, R. S., Kitchell, B. E., & Messick, J. B. (2003). Canine lymphosarcoma: Clinical features. Compendium on Continuing Education for the Practicing Veterinarian.
  • Peters, J. A. (1969). Canine mastocytoma: Excess risk as related to ancestry. Journal of the National Cancer Institute. https://doi.org/10.1093/jnci/42.3.435