P. 653

S. Ettinger1
Top Tips for Managing Chemotherapy Patients in Your Practice
Sue Ettinger, DVM, DACVIM (Oncology)
Dr Sue Cancer Vet PLLC and Animal Specialty & Emergency Center Wappinger Falls, NY, USA
“Cancer” is a scary word that is often equated with death. There is often a visceral fear of cancer, and pet owners think cancer equals pain and suffering. There are many myths and misconceptions about chemotherapy in pets. Owners think cancer treatment will just make the patient sicker.
Metronomic chemotherapy
In contrast to MTD chemotherapy, metronomic chemotherapy is pulse or low-dose continuous chemotherapy. This is typically administered daily or every other day. The target is endothelial cells in that line tumor blood vessel. The goal may be tumor is stabilized, but this prevents further growth and spread. Common chemotherapy drugs include Palladia, cyclophosphamide, and chlorambucil and also with NSAIDS. There is still much to be learned including best drugs, dose, schedule, tumor types, and toxicity. This can be considered for some dogs and cats with advanced metastatic disease.
Alopecia (hair loss) is due to damaging the rapidly dividing hair follicle. In dogs, potentially affected breeds have continuously growing coats and include Poodles, Scottish Terriers, and Westies. In cats, alopecia is
rare, but shaved areas tend to grow back more slowly (limb catheters, abdominal ultrasounds). Cats more commonly lose their whiskers. The good news is that hair and whiskers will re-grow once the treatments have completed. Occasionally, hair will grow back a different texture or color. In cats it is typically softer, aka the “chemo coat”. It is important to remember pets do not care about this cosmetic side effect, and it does not impact the quality of life. However, pet owners like to be advised about the whiskers and coat so they are not surprised.
Gastrointestinal (GI) toxicity
Gastrointestinal (GI) toxicity includes vomiting, diarrhea, decreased appetite, nausea. It typically 1 to 5 days after chemotherapy and is self-limiting – lasting on average 2-3 days. These side effects are less common in feline chemotherapy patients than dogs. I recommend being very proactive with nausea/anti-emetic drugs.
I often will use Cerenia or mirtazapine preventatively and as needed. I recommend giving Cerenia at administration with the following drugs: doxorubicin, vincristine, vinblastine, carboplatin, mitoxantrone, dacarbazine, and the MOPP protocol. If the pet has nausea/vomiting event within 24 hours of administration, I will add Cerenia SQ or IV at the time of administration at the subsequent treatment. For oral chemotherapy being given at home,
I advise the owner give oral Cerenia 1 hour before chemotherapy pill dosing.
I always recommend oral Cerenia for 4 days after doxorubicin in dogs to prevent nausea and vomiting.
An Urban Experience
But cancer is not a death sentence. With treatment, many cancer patients are not only living longer, but living well. Chemotherapy is well tolerated in the majority of dogs and cats undergoing treatment. Whether you are directly managing chemotherapy patients or sharing cases with an oncologist, there are simple tips and tricks to improve quality of
life and minimize side effects in chemotherapy patients.
Conventional Chemotherapy
Conventional chemotherapy is typically given at high dosages, known as maximum tolerated dose, or MTD. The goal is to kill the rapidly dividing cancer cells. But some normal cells that also have high turnover often can be temporarily damaged by MTD chemotherapy. The normal tissues that typically are most sensitive
to chemotherapy are the bone marrow, hair follicles (alopecia), and the gastrointestinal lining. This is often referred to as “BAG”. As a result there is a break period to allow these cell populations to recover. MTD is typically given weekly to every 3 weeks.
The overall toxicity rate is very low in veterinary chemotherapy patients. In my experience, only 15-20% experience side effects, and this is even less common in cats than dogs. The primary goal is to provide the best quality of life possible for as long as possible. As I say, live longer, live well. Most side effects are mild and medically manageable.

   651   652   653   654   655