Common Chemotherapy Side Effects


Vomiting: Withhold food and water for 12 hours, and then offer small amounts of water. If your pet does not vomit after drinking the water, offer small amounts of bland foods such as boiled chicken or boiled hamburger with boiled white rice. If still no vomiting, gradually reintroduce the pet’s normal diet in about three days. Call your veterinary hospital or an emergency veterinary service if the vomiting is severe or is accompanied by a fever greater than 103°F or persists longer than 24 hours.


Diarrhea: Offer your pet bland, easily digestible foods such as cottage cheese, boiled chicken or hamburger and white rice. Gradually reintroduce your pet’s normal diet. Pepto-Bismol can be given at one tablespoon per 15 pounds of body weight (dog) three times a day (every 8 hours) or ½ a tablet per every 7 pounds of body weight two times a day (every 12 hours). Call your veterinary hospital or an emergency veterinary service if the diarrhea persists for more than 48 hours or if it is associated with a fever greater than 103°F.
Dehydration: Dehydration can develop following vomiting, diarrhea, excessive urination or fever and may result in a prolonged recovery. Your pet’s gums should be moist and the skin should feel soft and compliant. If your pet is not vomiting, fresh water should always be available. Call your veterinary hospital or an emergency veterinary service if gums are persistently dry or if the skin does not feel normally supple. Fluid administration may be necessary to speed recovery.


Low White Blood Cell Count: The white blood cell count is expected to drop below normal after treatment, but will return to normal by the next treatment. This should not cause a problem unless the white blood cell count drops too low. When the white blood cell count drops too low, the body has difficulty fighting off infections. Infections may occur between 7-21 days after the drug is given. If this happens, symptoms may include a fever (temperature >103°F), lethargy (tiredness), vomiting, diarrhea, and a poor appetite. Some oncologists obtain a blood sample to be evaluated at the 7 day time point following treatment. If the blood count is low they may dispense antibiotics to prevent an infection.
If your pet shows any of the symptoms mentioned above, take your pet's temperature if you can (normal temperature is 100-102.5°F). If the temperature is greater than 103°F or if you cannot take the temperature, you should call your veterinary hospital or an emergency veterinary service. Your pet may need to be admitted to the hospital.


Bladder Irritation: Some anticancer drugs can cause irritation to the bladder called cystitis. This irritation can cause the urine to be bloody which is called hemorrhagic cystitis. Your pet may appear uncomfortable when passing urine, and strain frequently to pass only a small amount. Call your veterinary hospital or an emergency veterinary service if your pet has bloody urine or is straining to urinate. The doctor will most likely have you bring your pet in for a urine sample to determine the cause (drug reaction or bladder infection). If it is determined that the drug is the cause of the bloody urine, that drug will be stopped and another drug may be substituted. Your pet will be treated for the cystitis with antibiotics and anti-inflammatories.