What is Chemotherapy?
Chemotherapy treatments are drugs used to destroy tumor cells. They attack rapidly dividing cells common in most types of cancer. Most chemotherapy agents are injectable medications that have to be administered by specially trained veterinary professionals. Others are oral medications that can be given at the hospital or even at home in some cases.
At our hospital, we have a specialized area to treat our chemotherapy patients. This area is separate from the rest of the hospital to ensure safety as well as provide a calming environment for your pet. We also have specialized equipment to keep us, your pet, and you safe while administering chemotherapy.
Are there any side effects with chemotherapy?
The most important thing to remember about chemotherapy is that in animals we use relatively low doses as compared to those used in people. This causes our rate of side effects to be much lower than those you may have heard about or seen in friends or family members receiving chemotherapy.
- Only about 20% of animal patients have side effects from chemotherapy.
- Only about 5% will have severe side effects that could potentially put them in the hospital.
- About 15% will have side effects that are mild enough that they do not need hospitalization and can be treated at home with oral medications. These medications include anti-nausea medications, anti-diarrheal medications, appetite stimulants, and antibiotics.
What are the side effects of chemotherapy?
Chemotherapy attacks all of the rapidly dividing cells in the body. These include the cancer cells as well as the lining of the intestines and the bone marrow. When the intestines are affected, we can see decreased appetite, nausea, vomiting, or diarrhea. This usually happens between 3 and 5 days after treatment and can be treated with medications if symptoms are mild. If side effects are severe, your pet may need to spend a few days in the hospital getting IV fluids to prevent dehydration as well as other medications until they are eating and drinking again well on their own.
When the bone marrow is affected, we can see a low white blood cell or platelet count. This can cause lethargy, decreased appetite, diarrhea, fever and/or an infection. Even if the white blood cell count is very low, most patients do not show any symptoms, and oral antibiotics at home are the only treatment needed. If the white blood cell count is very low and your pet has a fever or feels sick, a stay in the hospital for a day or two on IV fluids and antibiotics until they are feeling better may be needed. The white blood cell count is routinely checked one week after chemotherapy administration, when the white blood cell count is at its lowest, to monitor for these problems and be proactive in treating this side effect.
How is chemotherapy given?
- Injectable chemotherapy is almost always given IV (in the vein) through a temporary catheter.
- Some treatments are given over a few minutes, some over 20-30 minutes, and some over several hours.
- Each chemotherapy drug has a specific way in which it needs to be administered.
- Oral chemotherapy is either given every few weeks at the hospital or daily to every other day at home by you.
Am I at risk if my pet has chemotherapy?
With most chemotherapy agents there are byproducts that are processed by the body and eliminated either through stool or urine. Most are processed to the point that they have little to no affect on other animals or people. However, there are some medications that can potentially cause harm to humans and other animals when eliminated from the body. Your pet’s oncologist will let you know what precautions to take and if you are at risk.
If any precautions should be taken, they are usually to pick up stool right away and limit any exposure of stool and urine from pregnant or nursing women. A few oral medications should be given with gloves and it is always a good habit to wash your hands immediately after giving any of these medications.
What type of cancer is treated with chemotherapy?
Most cancers can be treated with chemotherapy, however your pet’s oncologist will determine what type of treatment is indicated for your pet’s specific diagnosis. Every pet is different and it is important that each pet is evaluated on a case by case basis to ensure superior care. You will work directly with your pet’s oncologist to determine what the best treatment options are for your pet and your family. A list of cancers that may be treated with chemotherapy is below.
- Multiple myeloma
- Mast cell tumor
- Bladder cancer
- Mammary cancer
- Anal sac tumors
- Histiocytic sarcoma
- Injection site sarcomas
- Additional types of tumors