For many people, chemotherapy is a very emotive subject. Chemotherapy is defined as the treatment of disease using chemical substances; however, it is usually used more specifically to refer to the treatment of cancers using powerful medications. In humans these treatments are often associated with some pretty debilitating side effects; including severe fatigue, vomiting, loss of appetite and infertility. It’s understandable, therefore, that many owners worry when faced with the decision of whether they should put their beloved pet through a course of these powerful drugs.

What is chemo used for in dogs?

In dogs, the main cancers treated with chemotherapy include cancers that affect the whole body such as lymphoma (cancer of the lymph glands); cancers that are difficult to remove fully with surgery, such as bladder tumours; or cancers that are metastasising, or spreading, to other parts of the body. 

Prior to commencing a course of chemotherapy your vet will want to conduct tests to try and reduce the risk of serious side effects. The exact tests will vary depending on the specific medications, but may include a blood test or scans to check that your pet’s body is up to dealing with these medicines. These tests will often be repeated at regular intervals throughout the chemotherapy course.  

How is it given?

Chemotherapy medications can either be given as an injection or infusion carried out by a trained veterinary surgeon. Or sometimes via a tablet that owners will give at home. Frequently two or three types of chemotherapy medication will be given at the same time to try and make the treatment more effective.  

Is it as bad as in humans?

While veterinary chemotherapy certainly has some similarities to chemotherapy in human medicine there are some important differences. The biggest of these is that as veterinary surgeons we prioritise quality of life over quantity. What this means in practice is that the types of drugs we use and the doses that they are used at are less likely to cause the severe side effects that are tolerated in human medicine. 

This means that if side effects are seen, in most cases they are relatively mild. Your dog may be prescribed medications such as anti-sickness tablets or their chemotherapy doses may be reduced or delayed. The payoff for this is that unfortunately our success rates and chances of a cure are reduced. Despite this most vets agree it would be unethical to make a pet feel extremely unwell for a protracted period of time due to a treatment that we give. 

Is chemotherapy the right choice for my dog?

Chemotherapy certainly can be a good choice for some pets and owners. But it will still not be right for every dog. Your pet is likely to need frequent blood tests and procedures. Such as placement of an intravenous cannula so that the medication can be given directly into the bloodstream. If they dislike vet visits, find medical procedures stressful or needles very painful, you may need to consider whether this is the right course of therapy for them. The medications used for chemotherapy can be very expensive. And in addition may require lots of time consuming trips to the vets which may not be achievable for every owner. 

There is also the subject of human safety that should be considered. The chemotherapy drugs given to our pets are excreted into their bodily fluids including saliva, vomit, urine and faeces. This means that owners can potentially be exposed to them when caring for their pets. Extra care needs to be taken when dealing with urine or faeces, separate cleaning of food and water bowls is necessary, and soiled bedding needs to be washed separately from normal laundry. Owners who are pregnant, breastfeeding, trying to conceive or who have young children are at higher risk for problems. They need to carefully consider whether these risks can be safely managed.  

It is important to carefully consider whether chemotherapy is the right choice for your pet

If you do decide to go ahead, talk to your vet about any concerns that you have and follow their advice closely to minimise the risk to your pet and yourself. There are different types of chemotherapy available and your vet can discuss what each involves as well as how successful they are likely to be in treating your dog’s condition. Chemotherapy can help prolong your pet’s life and give you more precious time with your beloved animal. You can feel safe in the knowledge that your veterinary surgeon will not recommend any treatment that would cause undue suffering. 

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