Before we begin, a very brief lesson in cancer. Also known as neoplasia, cancer is the uncontrolled division of cells within the body. Any type of cell can potentially become cancerous. There are many reasons cancer occurs, including viral infections, exposure to carcinogens, which are cancer-causing substances (toxins, chemicals, cigarette smoke etc), genetics, age, and diet, to name a few.
Common terms used in cancer:
- Tumour - A growth, it may be cancerous or non-cancerous.
- Benign - A growth which doesn't spread to other parts of the body.
- Malignant - A growth caused by out of control cells which can spread to other parts of the body.
- Oncology - Referring to cancer and its treatment.
- Metastasis - Cancer which spreads to other parts of the body.
What is chemotherapy?
Chemotherapy is a drug used to treat cancer, it works by targeting rapidly dividing cells. Unfortunately, chemotherapy drugs don't discriminate and any cells which are rapidly dividing can be affected. This is why hair falls out in people undergoing chemotherapy. In adults, cell growth is reasonably slow, so not many 'normal' cells will be affected by the drugs.
Chemotherapy is usually used in conjunction with surgery and/or radiation therapy. It can be used in several ways:
- Prior to surgery to shrink the tumour.
- After surgery to kill any cancerous cells left behind.
- In some kinds of cancers (such as cancers of the blood or cancers which can't be surgically removed), chemotherapy may be the only treatment.
- To treat cancer that has spread (metastasized).
There are several types of chemotherapy drugs which will be selected according to the type of cancer your cat has. In some cases, a combination of drugs will be used. Chemotherapy isn't always going to cure your cat of cancer, but it can slow down the progression of the disease and buy your cat more time. For example, I had a cat with inoperable bone cancer, we always knew that the cancer would kill her, but giving her chemotherapy meant that we were able to have a few more months with her.
How is chemotherapy given?
Chemotherapy is given via injection or tablet. Not all veterinarians can administer chemotherapy in their practice, and you may be referred to a veterinary specialist centre for treatment. Most chemotherapy is administered via intravenous injection. Oral chemotherapy drugs are administered by the pet owner at home.
Prior to your cat receiving chemotherapy, he will have routine bloodwork done to check his white blood cell count, red blood cell count, and platelet counts. If any are too low, chemotherapy will be delayed.
Are there any side effects to chemotherapy in cats?
Chemotherapy doesn't have as many side effects in cats as it does in humans. They don't lose their hair like we do. As we have already mentioned, chemotherapy drugs target rapidly growing cells, and not only is the cancer affected, but also other cells which grow rapidly such as those in the gastrointestinal tract and the bone marrow.
However, some side effects can occur, these may include:
- Gastrointestinal upset such as vomiting and diarrhea are quite common. Both usually resolve within a day or two.
- Weakened immune system due to decreased white blood cell count, this can make your cat more vulnerable to infection.
- Lethargy (I always found my cat would be quite lethargic for 1-2 days after she had received chemotherapy).
- Dehydration can occur if your cat is experiencing vomiting and/or diarrhea.
- Loss of appetite.
- Some hair loss can occur in cats but it isn't as severe as experienced in people undergoing chemotherapy.
Keep a close eye on your cat and if you notice any symptoms, seek veterinary advice immediately.
Is chemotherapy expensive?
Yes, it can be. Prices vary from clinic to clinic, the type of drugs being administered and of course the frequency.
How often is chemotherapy treatment?
This varies depending on the type of cancer and the treatment options but it can range from weekly to every month or so.
Should I give my cat chemotherapy?
This is a tricky one and it is up to you and your veterinarian to decide. There are several factors at play. Is the cancer one which can easily be treated (some types of cancer are more aggressive than others), the overall health of your cat, and his age.
It is extremely important to find a veterinarian you can trust and who can guide you. They can't make decisions for you, but they can give their opinion on what they feel is the best and kindest course of action to take. In some cases, where the cancer is advanced, treatment may not be in your cat's best interests.
Sadly, sometimes the cost also factors into your decision. Chemotherapy isn't cheap and not everybody can raise the funds. I spent approximately $3,000 having my cat diagnosed and then treated for cancer, that was in 2003, so I would imagine it would be a lot more now. Of course, the type of cancer and the stage all come into play, some cancers are easier to treat than others, but certainly, the cost can come into play.
Is there any special aftercare once my cat had undergone chemotherapy?
He may not feel well for a day or so, so a bit of extra care won't hurt. Be mindful that he may not feel like eating and try to encourage him to do so with special treats such as cooked chicken, this is particularly good because it is reasonably bland too. Warming up his food may also encourage him to eat.
The drugs are excreted from the body via the urine, so care should be taken when cleaning out litter trays. Always use rubber gloves when handling the litter tray. Pregnant or lactating women and children should avoid cleaning out litter trays anyway, but particularly in cats who are undergoing chemotherapy. Any dirty litter should be disposed of in the garbage.
It is also recommended that pregnant and lactating women avoid contact with their cat for 2-5 days after treatment.
Your veterinarian may also have prescribed painkillers and/or antibiotics while your cat is undergoing treatment. Always follow the instructions.