Chemotherapy in Pets – Frequently Asked Questions
Will chemotherapy make my pet sick like it does people?
In general, dogs and cats do not have as severe side effects from chemotherapy as people do. Our goal is to maximise quality of life as much as possible and many pets have no significant side effects from chemotherapy at all. Approximately 10% or less have side effects severe enough to need to be seen by a veterinarian. Approximately 1% or less have life-threatening side effects. Individual drugs may have varying side effects. If you have any concerns about your pet following chemotherapy, please call us to discuss, or have your pet seen by a veterinarian.
The most common side effect is mild lethargy for a day or two after chemotherapy. Gastrointestinal side effects (nausea, vomiting, diarrhoea) can also occur in some patients, usually starting a few days after chemotherapy. In some cases they can happen sooner (within a day) or later (a week or more) after treatment.
Chemotherapy can also cause low white blood cell and platelet counts. The timing depends on the drug and can vary from a few days to up to a couple of weeks after treatment. We check a complete blood count (CBC/haemogram) after each chemotherapy treatment at the time white blood cells are most likely to be low. In most cases, low white blood cell counts and platelet counts are not concerning and recover without any treatment. If the white blood cell count gets very low, pets may pick up an infection since their immune system cannot function normally. This may show up as lethargy (not wanting to move as much, not as interested in food, not wanting to get up and play), with or without other signs. In most cases this will be associated with a fever (rectal temperature above 39oC). This is an emergency and if this happens, your pet should be seen at once. Platelets are cells that help with blood clotting, and if platelets become very low then pets may be at increased risk of bruising under the skin or bleeding (e.g. from the nose, gums or in the urine or feces), however any significant bleeding is uncommon.
Most animals do not lose a lot of hair with chemotherapy, though hair that is shaved can take a long time to grow back, dogs with ‘feathers’ on their legs and tails will often lose these, and most dogs and cats will lose whiskers. Dogs with constantly growing hair (e.g. Poodles, Bichon Frise) will often lose quite a lot of hair. Rarely, coat can change color after chemotherapy treatment.
What should I do if my pet has chemotherapy side effects?
We send home anti-nausea (e.g. metoclopramide, ondansetron, Cerenia) and anti-diarrhoea medications (e.g. metronidazole, Tylosin) at the first chemotherapy treatment so that you have these on hand if needed. After some chemotherapy treatments, we may send home additional anti-nausea medication and have you start giving this straight away for a few days.
When pets are nauseated, they may not want to eat as much or may eat more slowly than usual, they may drool or lick their lips excessively or they may turn away from food when offered. If you see any of these types of behaviors, you can start the anti-nausea medication straight away – you do not need to see your pet vomit in order to start. Similarly, if you see
that their stool is becoming softer, even if it is not obvious diarrhoea, you can go ahead and start the anti-diarrhea medication. If the medications are not helping within 24 hours, please call us to discuss. There are often other medications that we can prescribe or call in for you.
In cases of low white blood cell counts and fever, this situation can be an emergency and pets should be seen as soon as possible. Usually pets are admitted to hospital for intravenous fluids and antibiotics and are able to go home in 1-2 days.
If there is reduced food intake (<50% of normal) for three days or more, there is ongoing vomiting or diarrhoea despite medications, significant lethargy, fever, or you are concerned at any time, please call to discuss. In most of these cases, we recommend evaluation by a veterinarian.
Why does my pet need blood tests during chemotherapy?
Because of the potential for chemotherapy side effects such as low white blood cell counts, we check a blood test before each treatment, and often after treatment as well. Some chemotherapy drugs can also cause liver or kidney problems and in those cases we also check a serum biochemistry panel before each treatment. The blood tests immediately before chemotherapy are typically done here on the morning of the scheduled treatment. In some cases, we may get results from those tests which mean we do not give the scheduled treatment (e.g. white blood cell count is too low). Blood tests after chemotherapy can be done here or with your regular clinic, and the results faxed (9731 2377) or emailed (email@example.com) to us. If your pet
is not feeling well or you have questions for a doctor, please call before bringing your pet in for a routine post-chemotherapy blood test.
Can my regular veterinary clinic do the chemotherapy treatments?
Some primary care clinics can do chemotherapy treatments, though many cannot. We are happy to offer general advice regarding cancer care and treatment to your regular clinic, but we cannot give specific advice regarding protocols, drug dosages and management during a chemotherapy protocol.
Why are there so many treatments? Can we stop chemotherapy early?
Chemotherapy protocols involve multiple treatments to give us the best chance of controlling cancer for as long as possible. We may recommend stopping chemotherapy if it is not working or if side effects are not tolerable, but otherwise we do not recommend stopping early. Even if remission has been achieved, in many cases the cancer is still active at a microscopic level and stopping early may mean that it will progress more quickly. However, you are under no obligation to continue a chemotherapy protocol if it is not working for your family for whatever reason.
What if I need to delay a treatment?
We sometimes delay chemotherapy treatments if there are side effects, but otherwise do not recommend delays. If a delay is unavoidable (for example due to travel), then postponing one treatment for a short period of time is unlikely to have a significant impact on the outcome of treatment. However, multiple delays may reduce the efficacy of treatment.
Can I feed my pet the morning before chemotherapy?
In general, it is fine to feed and give medications as normal before chemotherapy treatments. If sedation is needed for any reason (for example, an ultrasound) then we ask that you do not feed your pet breakfast that morning. In this situation, you can give medications in a very small amount of food (e.g. small piece of cheese or hot dog) if needed. There is some data that fasting prior to chemotherapy (up to 24 hours) may reduce the severity of gastrointestinal side effects of chemotherapy, so this may be something to consider for dogs who are having nausea after chemotherapy treatments.
Are there diet restrictions for pets receiving chemotherapy like there are for people?
We do not recommend raw diets for animals receiving chemotherapy. Some animals require prescription diets for specific conditions. Otherwise, we recommend your pet is eating a good quality, balanced diet that he/she enjoys. If you are interested in home-cooking for your pet, we recommend a consultation with our nutrition service.
Do animals need to be sedated for chemotherapy treatments?
Usually not. Most chemotherapy drugs are given by short intravenous injection and so once an IV catheter is placed the treatment is very brief. For longer infusions (e.g. doxorubicin/Adriamycin) pets need to stay still for longer (20-30 minutes) and in some cases sedation is needed.
What can my pet do during chemotherapy? Can I take them to a boarding facility/day care/dog park/on holiday/dog show while they are receiving chemotherapy? In general, pets can do all of their normal activities during their chemotherapy treatment e.g. going for walks, running, swimming if they are feeling well. It is also fine for them to travel or mix with other dogs. If their white blood cell or platelet counts are low or are expected to be low after treatment, we may recommend that they do not travel or mix with other dogs as much to reduce potential risks – though in reality the risk is likely very low. With regard to boarding, please discuss with your boarding facility well in advance since close monitoring or medications may be needed.
Are there any risks to myself, my family or other pets from the chemotherapy my pet is receiving?
While there is limited data available, we do know that chemotherapy drugs can be present in small quantities in urine, faeces, vomit, and saliva of patients that have received chemotherapy. Although the risk to your family from potential exposure to chemotherapy is thought to be very low, this has not been directly studied. The clearing times for these drugs can be anywhere from 15 minutes to a couple of weeks. It is always recommended to limit direct contact with bodily fluids/excretions (including urine, faeces, vomit and saliva) in the days directly following chemotherapy treatments. Always wear gloves when cleaning up waste. Faeces can be picked up and discarded in the rubbish by double-wrapping in plastic bags. Urine or vomit should be mopped up with paper towels and the dirty paper towels should be discarded, double-wrapped in plastic bags. If your pet urinates on a hard surface, it should be diluted with plenty of water and cleaned as above. If you have another dog that tends to eat faeces then you will need to be vigilant about immediately cleaning up after defecation. Avoid being licked by or kissing your pet after chemotherapy, and wash your hands after playing with your pet. If you have kids at home, make sure to speak to them about how to handle your pet. Similarly, inform any visitors if you do have a dog that is very social.
When we prescribe chemotherapy tablets or capsules to be given at home, the medication should be stored out of reach of children or other pets and away from food/other medications. Gloves should be worn at all times when handling chemotherapy medications and the packaging. These tablets should not be split or crushed and capsules should not be opened. Keep the medication in its original packaging and return any unused medication to use for safe disposal.
Watch your pet ingest the tablet or capsule - do not just put it in the food bowl. NOTE: You may wrap a small amount of food (cheese, sausage, butter, peanut butter etc.) around the medication. In cats we recommend that you give the medication (wrapped or not) directly into the mouth. A good video on how to give oral medication in cats can be found here: http://partnersah.vet.cornell.edu/pet-owners/pill
Give 2-5 ml water slowly with a syringe, or a small amount of tempting food, after the medication, to make sure that the medication has been completely swallowed.
Pregnant or breast-feeding women should not handle chemotherapy medications and should avoid contact with the urine, faeces and vomit of pets receiving chemotherapy.
Can my pet have vaccinations while they are receiving chemotherapy?
We generally recommend holding off on routine vaccinations for animals receiving chemotherapy, as cancer and chemotherapy may mean your pet is less likely to mount an effective immune response to the vaccine. If your pet is not feeling well for any reason, vaccination is not recommended.
Can my pet have flea/tick/heartworm prevention medications while receiving chemotherapy?
Regular flea prevention and heartworm medication is recommended, as directed by your regular veterinarian, and does not interfere with the chemotherapy treatments. Bathing and grooming your pet as you have in the past is fine as well.
How do I schedule chemotherapy appointments?
After you have decided to begin chemotherapy for your pet, please call us to schedule. We will work with you to pick a day of the week that works best with your schedule and will schedule all following appointments to fall on the same day of the week. Chemotherapy treatments are generally scheduled Tuesday-Thursday.
What happens when I bring my pet in for chemotherapy treatments? Your pet needs to be dropped off between 7:30 and 9:00 am on the day of their scheduled chemotherapy. You will briefly meet with one of the nurses to discuss any concerns you may have about your pet’s condition. If there are concerns about your pet during the day or if you have specific questions prior to pick-up, the vet taking care of your pet for that day will call you to discuss. Otherwise, we will call you to set up a time in the afternoon for discharge, or if you need to pick up your pet later in the day the vet will call with any instructions.
Once your pet is dropped off, the technicians will do a brief physical exam and draw any necessary blood samples. The vet overseeing your pet’s care for that day will then perform a thorough exam on your pet. While here, your pet will have access to water at all times and will be walked outside. If there is medication or food that needs to be given at a specified time, you may drop it off with your pet. Please make sure all medications are in their original container with a label. Once as the blood test results for all chemotherapy patients are back from the lab and reviewed by the vets, the chemotherapy drugs are prepared and the chemotherapy treatments are given in the afternoon.