FAQ-Cancer Resource Center-Lab Work

Blood work is done to monitor the effects of the chemotherapy, not necessarily monitoring the cancer (with a few exceptions such as leukemias). Blood work being normal does not mean that the cancer is gone, only that the treatment is not harming the body.


For most patients, as long as they start antibiotics within 24 hours of getting the chemotherapy, it should not make a difference.

Why is this important?
Chemotherapy kills the rapidly dividing cells in the body. There are 3 groups of rapidly dividing cells in the body--the cancer cells, the bone marrow cells and the cells lining the gastrointestinal tract. When chemotherapy kills some of the bone marrow cells, they tend to kill the cells that make white blood cells (WBC). These WBCs are the cells that protect pets from infection. If the WBC count gets too low, infections can occur. We therefore recommend antibiotics to try and prevent infections from taking hold and therefore preventing your pet from feeling ill due to the low WBC/infection.

How do doctors check for low WBC counts?
A simple blood test, either run in the hospital or sent to a lab is a complete blood count (CBC). This blood test indicates the number of red blood cells, white blood cells and platelets that your pet has. These tests are very routine and are run before each and every time your pet receives chemotherapy.

What are the signs of infection?
The most common signs of infection are fever (high temperature--in dogs and cats the normal temperature is 100-102.5). The other common signs are lethargy (loss of activity level), anorexia (loss of appetite) and sometimes diarrhea and nausea.

When will my pets WBC count drop?
This low WBC counts may occur anytime from 1 to 14 days after chemotherapy, depending on the drug.

Where should I go if my pet shows greater than mild signs of infection?
If your pet is showing any of the above signs and they seem more than just mild to you, please contact The VCC, your local veterinarian or the closest 24 hour emergency center.

It is common in cancer patients receiving IV treatment to see scarring of the veins due to repeated injections. In order to preserve the integrity of the veins of the legs for chemo injections, blood draws should ideally be pulled from the jugular vein in the neck.