Cancer is a common canine concern. Dog cancer affects an estimated 25% of all dogs and 30% of dogs over 7 years old, according to the AKC Canine Health Foundation (CHF). It’s the leading cause of death in older pets, with as many as 50% dying from cancer.
The shock of a cancer diagnosis for your pet can bring with it a lot of questions. What options are there for dogs with cancer? Is chemotherapy one of them? What’s involved in chemo treatment, and is it worth it? We spoke to Dr. Diane Brown, DVM, Ph.D., DACVP, the Chief Executive Officer and Chief Scientific Officer of AKC CHF, to answer these canine chemotherapy questions.
What Is Chemotherapy for Dogs?
As with humans, chemotherapy for dogs is a series of drug treatments. Chemotherapy works to stop or slow the growth of rapidly spreading cancer cells by preventing them from dividing and multiplying. Chemo can sometimes help slow the progression and spread of cancer throughout your dog’s body, reduce tumor size before surgery, and improve the dog’s response to other anti-cancer treatments.
How Does Canine Chemotherapy Differ From Human Treatments?
Veterinarians administer the same types of chemo drugs to dogs that doctors administer to human cancer patients. In humans, drug doses are high, and treatment is aggressive. While chemotherapy can cure cancer or extend a person’s life, it usually results in severe side effects.
Chemo treatment for dogs involves significantly lower doses of drugs. On its own, chemo for dogs isn’t likely to cure your pet. However, chemo can help your dog enjoy many more months (or even years) of comfortable life without suffering from severe side effects.
What Types of Canine Cancer Does Chemotherapy Treat?
There have been significant advancements in chemotherapy treatments for dogs in recent decades. However, chemotherapy doesn’t work to treat all canine cancers. For example, oral melanomas are resistant to chemotherapy treatment. Even when studies show positive results, chemo benefits depend on various factors. These include the cancer type, the stage of its development, other available treatments, and your dog’s age and overall health and well-being.
Some canine cancers your vet might discuss the possibility of treating with chemotherapy include osteosarcoma, transitional cell carcinoma, hemangiosarcoma, and lymphoma.
There are over 30 types of canine lymphoma, and studies show chemo is the most effective treatment for most of these. In many cases, treatment results in the disease going into remission, with no detectable signs of the cancer being in the body for an extended period. Treatment often involves administering a combination of chemo drugs overall several months.
A veterinarian or a veterinary oncology specialist will recommend treatment options for the type, grade, and stage of cancer. These and other factors will also help determine if other treatment options, such as surgery, radiation, immunotherapy, complementary therapies, or a combination of therapies, are a fit,
How Are Chemo Treatments for Dogs Administered?
How a dog receives chemo treatment depends on the type and severity of the cancer. Often veterinarians administer the drugs intravenously to your dog as a day patient. Occasionally veterinarians inject the medication directly into the tumor, a muscle, or a body cavity, like the abdomen. Other times, owners can dispense oral medication at home.
How Long Does Chemo Treatment for Dogs Last?
“It’s very individualized based on the type of cancer, the stage, and the treatment that’s recommended,” says Dr. Brown. “So, there’s no single one answer.” A course of chemo typically involves multiple treatments. Some are administered daily, some weekly, and others every few weeks. Some dogs may stay on chemo for the rest of their lives. Others may receive sporadic treatment or end treatment altogether if their cancer clears up or goes into remission.
How Much Does Chemotherapy for Dogs Cost?
There’s also not one answer to the question of cost, as this also varies by type of cancer and stage. However, chemotherapy treatment for dogs can be expensive and pet insurance doesn’t always cover it. Costs range from $150 to about $600 per dose, according to the Veterinary Cancer Society. This means treatment could set you back anywhere from several hundred dollars to several thousand (or more).
What are the Side Effects of Chemotherapy for Dogs?
Side effects vary widely. Much depends on the type of treatment, the dose, and the dog’s overall health and individual reaction.
Dogs tolerate chemo much better than humans, with side effects usually being mild and manageable at home. Adverse effects typically only affect 20 to 25% of patients. Some of the most common symptoms include:
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Gastrointestinal issues: Most commonly, dogs suffer from symptoms such as nausea, vomiting, or diarrhea. These usually only last for a few days after treatment and are controllable with medication and diet adjustments.
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Blood marrow suppression: This results in a decrease in white blood cell counts, leading to a greater risk of contracting infections. Stay vigilant to early signs of infection which would typically occur around seven days after chemo administration. These include a high temperature, vomiting, lack of appetite, weakness, increased heart rate and rapid breathing. When counts are particularly low, your vet might prescribe antibiotics as a preventive measure and recommend avoiding a raw food diet during treatment.
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Coat changes: Unlike with humans, hair loss is rare. However, it is more likely to affect breeds with continuously growing hair, like Poodles or Maltese. Other dogs may experience changes in coat texture or color.
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No appetite, weight loss: Vets can offer medication to help stimulate your dog’s appetite.
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Urinary tract infections: Again, these can be cleared up with medication from your vet.
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Lethargy
Your dog will attend regular check-ups during chemotherapy treatment, and your vet can adjust the protocol if side effects are severe. If your dog experiences any out of the ordinary, worrisome, or prolonged clinical signs, always discuss these with your veterinarian.
Safety Considerations During Canine Chemotherapy
The risk to you or other family members is small. However, avoiding unnecessary exposure to chemotherapy drugs is a sensible precaution. Your vet will talk you through specific handling guidance, but some general safety measures include:
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Feces and urine contain traces of chemo drugs for 72 hours to several weeks after treatment. However, the highest concentrations are present within the first few days. Where possible, avoid contact with feces and urine during that time.
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If your dog urinates, vomits, or has diarrhea in your home, use gloves to clean it up and wash your hands thoroughly afterwards.
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Avoid cleaning up feces or urine if you are pregnant, trying to conceive or breastfeeding.
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Wash soiled bedding separately on a hot cycle twice.
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Pick a no- or low-traffic space to allow your pet to go potty to prevent unnecessary exposure for other pets and people.
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Use gloves to administer oral medications and wash hands after.
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Supervise your pet’s interactions with children, and always wash hands after contact.
Is Chemotherapy Worth it For Your Dog?
While the overriding factor of whether chemotherapy treatment is right for your dog relates to their quality of life, other factors can also influence your decision. These include:
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The type of cancer: Some cancers, like lymphoma, respond very well to chemo treatment. The UW-25 protocol is a common lymphoma treatment which lasts six months. As many as 80% of dogs on this protocol will go into remission, and it can be over a year before they require further treatment.
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The stage of cancer: If your dog has cancer that has aggressively metastasized (spread into various parts of the body) and shows signs of pain and discomfort, chemo treatment may not help improve or extend their quality of life.
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Financial considerations: Non-curative and expensive chemo treatments can be a significant commitment.
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Your dog’s age and health: Does your dog have other health issues, like heart or kidney disease? Ask about these and other factors affecting your dog’s overall comfort.
Learning about cancer and chemo can be overwhelming and raise a lot of questions. To ensure you get all the answers you’re looking for and to help you make a decision on the way forward, Dr. Brown recommends:
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Ensure you receive a definitive diagnosis: This will involve testing (such as X-rays and a biopsy), getting results, and determining if additional diagnostic testing is needed (such as an MRI).
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Figure out a timeline: In some cases, there may not be much time to research your options. Therefore, make sure you have a plan in place for different scenarios.
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Get all the guidance you need: One way to do this is by having open discussions with your veterinarian. Additionally, consider seeking counsel from a canine oncologist.
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Learn from others going through the same thing: Support groups may be available near you for families with dogs with cancer.
To learn more, including how you can help fight canine cancer, get involved in supporting canine cancer research for dogs through the CHF’s Canine Cancer digital resource.
This article is intended solely as general guidance, and does not constitute health or other professional advice. Individual situations and applicable laws vary by jurisdiction, and you are encouraged to obtain appropriate advice from qualified professionals in the applicable jurisdictions. We make no representations or warranties concerning any course of action taken by any person following or otherwise using the information offered or provided in this article, including any such information associated with and provided in connection with third-party products, and we will not be liable for any direct, indirect, consequential, special, exemplary or other damages that may result, including but not limited to economic loss, injury, illness or death.