24/7 Emergency
The American Veterinary Medical Association estimates one dog in four will develop some form of cancer, including half the dogs who live longer than 10 years. Less data has been collected about cats, though the cancer center at Colorado State University estimates the rate at one in five. Sometimes surgery can help. Sometimes cancer moves so rapidly and widely that nothing will stop it. But in recent years, pet chemotherapy has become a valuable solution, especially as most animals tolerate it well.
Pet chemotherapy works differently from chemotherapy for humans, partly because the veterinarian wants to preserve quality of life for as long as possible rather than aggressively seeking a complete cure. But a pet owner whose animal has been diagnosed with cancer needs to be aware of the terrain.
Reasons for Cancer Frequency
Some dog breeds – for example, golden retrievers, boxers and Bernese Mountain Dogs — have a higher genetic predisposition to cancer. Some cats, especially purebreds such as Siamese, also have genetic predispositions, though less pronounced than in dogs.
Cancer risk increases with age, due to the accumulation of genetic mutations. As pets live longer because of better care and veterinary advances, their likelihood of developing cancer rises.
Environmental factors such as exposure to pesticides, secondhand smoke or certain chemicals increase risk. Hormonal Influences play a role in certain cancers, such as mammary tumors in unspayed female dogs and cats.
Chronic inflammation or infections, such as feline leukemia virus or feline immunodeficiency virus in cats, can increase the risk of certain cancers. As in humans, poor nutrition and obesity contribute to cancer risk by causing chronic inflammation and influencing hormone levels.
Treatment Options
Pets’ treatments must be tailored to their specific type, stage, and overall health and quality of life of each pet. Here are the main types of treatments:
- Surgery can remove or debulk tumors; it’s often used as the primary treatment for solid tumors that are detected by a biopsy and can be removed with clear margins and no evidence of spread.
- Radiation therapy may kill cancer cells or shrink tumors that are difficult to remove surgically or are highly sensitive to radiation, such as nasal tumors, brain tumors or soft tissue sarcomas.
- Immunotherapy, such as a melanoma vaccine for dogs, can boost the body’s immune response against cancer cells. In targeted therapy, drugs specifically target cancer cell pathways while minimizing damage to normal cells.
- Palliative care or nutritional therapy focuses on managing symptoms and improving quality of life with pain management, anti-nausea medication, appetite stimulants, steroids and changes to diet. Steroid therapy may be added to reduce inflammation, shrink certain tumors and improve appetite and comfort.
- In many cases, however, chemotherapy – using drugs to kill cancers and slow their growth — may be the right choice, especially for systemic cancers such as lymphoma, leukemia, or high grade and metastatic cancers. Doses are adjusted to minimize side effects in pets.
When to Use Pet Chemotherapy
Veterinarians base this decision on several factors, including the type of cancer, the animal’s overall health, expected quality of life and goals of treatment. The decision to proceed is made collaboratively between the veterinary oncologist and the pet owner. It must balance medical recommendations with the owner’s capacity to manage the treatment. Here are the key considerations:
Type and stage of cancer
Some cancers, such as lymphoma, osteosarcoma, and certain mast cell tumors, respond well to chemotherapy, while others do not. Staging (how advanced the cancer is) helps determine if chemotherapy would be effective.
Prognosis and treatment
Goals can range from attempting to cure the cancer to simply improving quality of life by reducing tumor size or slowing progression. Chemotherapy is often considered when it can extend survival with good quality of life.
Overall health
Veterinary oncologists assess the animal’s age, general health and any underlying conditions that might affect the ability to tolerate chemotherapy.
Potential side effects
Pet chemotherapy is generally aimed at minimizing potential side effects. Owners may encounter gastrointestinal upset, lethargy or immunosuppression.
Owner’s goals and commitment
Owner preferences, financial considerations and willingness to manage side effects play a significant role. Veterinary oncologists discuss expected outcomes and provide an overview of the treatment process to help owners make informed decisions.
Quality of life considerations
Maintaining or improving the pet’s quality of life is a priority. If chemotherapy is likely to cause more discomfort than benefit, alternatives such as palliative care may be considered.
Response to previous treatments
If the pet has undergone surgery or radiation, chemotherapy might be recommended as an adjunct to reduce the risk of recurrence or manage residual disease.
Charlotte Animal Referral and Emergency operates like a human-style medical center for pets, running 24 hours a day, 365 days a year. CARE provides every type of treatment, from emergency room intervention to board-certified specialty work after a referral from your primary care veterinarian. You can take a visual tour of the practice at carecharlotte.com/tour.
