Approximately 1 in 4 dogs will, at some stage in their life, develop cancer. Almost half of dogs over the age of 10 will develop cancer. Dogs get cancer at roughly the same rate as humans, while there is less information about the rate of cancer in cats. Some cancers, such as lymphoma, are more common in cats than in dogs.
Some cancers, such as skin tumors, can be completely removed via surgery. These are the most common cancers we see and perform these surgeries on a daily basis. Others, such as generalized lymphoma, must be treated with chemotherapy. Chemotherapy in our pets is much different than the experiences we are familiar with in humans. We use much smaller drug doses than in humans, thus leading to less side effects. Our goal is to improve quality of life primarily and to hopefully get some bonus months with our pets after their diagnosis. You can read testimonials in a blog post from other pet parents about their experiences with NAAH and chemotherapy.
The prospect of chemotherapy for your pet may be intimidating or even scary. The good news is that pets typically handle chemotherapy much better than people. Knowing how chemotherapy drugs work and what to expect from the treatments can help you decide whether this therapy is right for your pet. The following represent some of the most common questions relating to chemotherapy for pets with cancer.
WHAT IS CHEMOTHERAPY?
Chemotherapy is drug therapy designed to kill or slow the growth of cancers. Many of the drugs used to treat cancer are derived from natural substances such as plants, trees or even bacteria and are often the same drugs used in people. Some drugs have a broad spectrum of activity, while others are more targeted.
WHEN DO WE USE CHEMOTHERAPY TO TREAT PETS WITH CANCER?
Chemotherapy may be used as the primary treatment for certain cancer types, or may be used in combination with other treatments such as surgery and radiation therapy. In some cases, chemotherapy can be used to try to shrink large tumors prior to surgery, or to help eliminate microscopic cancer cells that cannot or have not been completely removed surgically. For cancers that are at high risk for spread, chemotherapy can be used after surgery to help delay or prevent the appearance of cancer in other parts of the body.
WHAT IS THE GOAL OF CHEMOTHERAPY?
The goal of chemotherapy is to control or eliminate the cancer while still providing the highest quality of life to your pet. Chemotherapy drugs sometimes do not cure cancer but rather control the cancer by killing cells and slowing the progression of the disease.
HOW IS CHEMOTHERAPY GIVEN?
There are different formulations of chemotherapy. Some drugs must be given intravenously (IV), others may be given under the skin or into a muscle. In some cases the drug may be injected directly into the tumor itself. Some chemotherapy can be given orally in pill form.
WHAT SORT OF SIDE EFFECTS MAY MY PET HAVE WITH CHEMOTHERAPY?
The highest quality of life for your pet is our goal, but to be effective in controlling a devastating disease like cancer, chemotherapy drugs are very powerful. Fortunately, pets don’t have as many side effects as humans going through chemotherapy do. In fact, 70% of pet patients face few, if any side effects. Hair loss is common in humans but rare in dogs. It is seen mainly with breeds that have constantly growing hair (poodle, shih tzu, cocker spaniel, etc.). Cats generally do not lose body hair, but often lose their whiskers. Other potential side effects include nausea, vomiting, diarrhea – most of which are readily controlled with medications/diet change and only last for a day or two. A common side effect with many chemotherapy treatments is a decrease in the white blood cell count. This could make your pet more susceptible to contracting infections if the decrease is severe. We will check this in our laboratory before each chemotherapy.
HOW LONG WILL MY PET RECEIVE CHEMOTHERAPY?
Many chemotherapy protocols involve a series of treatments, followed by a period of careful observation. However, in some patients with advanced disease, chemotherapy may be continued as long as it is controlling the cancer.
WHAT HAPPENS WHEN CHEMOTHERAPY NO LONGER CONTROLS THE CANCER?
Cancers can be initially very sensitive to chemotherapy drugs. Unfortunately, the cancer may return weeks, months or years later. In such cases, the cancer cells have become resistant to the drugs in a similar way bacteria become resistant to antibiotics. When resistance to one drug occurs, we can often use other drugs. However, each time resistance develops it becomes more difficult to find a drug that the cancer will respond to. In some cases, cancer develops resistance to all drugs. At this point, we will discuss with you ways to keep your pet comfortable for the remainder of their life.