Wellness Checkup for Cats - Understanding the CBC Results

We've talked about the importance of taking your cat to the vet for wellness checkups in addition to times when she may be ill. A normal wellness checkup will include taking measurements of weight and temperature; examination of the ears, eyes, and teeth; and necessary vaccinations. Many vets will request blood tests for your cat. What do the results of these tests tell you?

Truffle in her Sleepypod® on the way to the veterinary hospital

Your vet may recommend a blood test which includes a Complete Blood Count (CBC) and a Blood Chemistry Panel.

The CBC provides information about different cell types in the blood and can indicate the presence of many forms of infection, inflammation, and disease, such as anemia and leukemia. A CBC provides information about the three types of cells found in the blood: red blood cells, white blood cells, and platelets (Ruotsalo, 2015). The Superchem Blood Test is a comprehensive blood chemistry panel that provides a good overview of many of the body's functions of your feline. Your vet will receive a detailed analysis of these two tests and will combine the information with physical examination findings, your cat's medical history, and other information to assess your cat's health status and determine if additional testing should be recommended. 

This post is the first of a two-part series discussing the results of the CBC and the Blood Chemistry Panel.

Analysis of Results

Brulee getting her vaccination at her recent wellness checkup and
the results of her Superchem and CBC blood tests

Complete Blood Count (CBC)

There are several words and acronyms listed on a CBC report. The photo above shows Brulee's recent CBC test on April 3, 2019 during her wellness checkup. What do all of these represent?

There are three main categories in the CBC report: Total White Blood Cells (WBC), Platelets, and Red Blood Cells (RBC).

White Blood Cells (WBC)

The White Blood Cells numbers measures immune cells and tells how many of each type of white blood cells are present and whether the count is normal, low, or high. White blood cells help to fight infection in your feline's body. If there is a severe infection or bone marrow disorders, the white blood cells can decrease. White blood cells can increase if there is inflammation or infection. Cats who have allergies or parasite infections may have increased Eosinophils.

• Neutrophils (2500-8500). The most common white blood cell in dogs and cats. The neutrophils are the body's "first responders" (Giese, 2015) and arrive quickly to the scene of an injury or infection and release signals to other white blood cells and healing agents to a site of inflammation. An increase may signal an inflammatory response, while a decrease may indicate a viral disease, toxins, or an overwhelming infection.
• Lymphocytes (1200-8000). The second most common white blood cell in the body that are important for immune response. Lymphocytes are triggered into action when they encounter antigens, which are specific proteins on the surface of an invading microorganism. An increased number could mean there is an immune response which could be related to a vaccination or indicate a fear or excitement response. A decrease in numbers can indicate a stress response or increased levels of cortisol.
• Eosinophils (0-1000) A type of white blood cell that is particularly involved with defense against parasites, such as heartworms, roundworms, and hookworms. They also play a role in allergic reactions. Eosinophils are increased especially during hypersensitivity responses. 
• Basophils (0-150). Basophils are similar to eosinophils, but are present in much smaller quantities. They would also increase during an allergic or parasitic response.
• Monocytes (0-850). Monocytes develop and are stored in the spleen and bone marrow. Monocytes have the ability to "eat" foreign material such as infectious organisms. The monocytes numbers do not vary much unless there is a cancerous leukemia condition.
• Platelets (190-800). Platelets serve a vital function in the formation of clots. If platelet numbers decrease, it may mean that the body has either used up a large quantity of the available cells in clot formation or that your feline is at great risk if bleed occurs in the future.

Truffle being examined by Dr. Boyette during her 6-month checkup wellness visit

Red Blood Cells (RBC)

The main function of red blood cells is to carry oxygen to the tissues in the body. Oxygen is carried within red blood cells by molecules called hemoglobin. "The metabolism in a cat is geared to protect both the red blood cells and hemoglobin from damage, interference with the formation or release of hemoglobin, the production or survival of red blood cells, or their metabolism causes disease" (Cotter, 2019). Anemia occurs if the red blood cells is too low. Animals can be weak and fatigued is their red blood cell count is low. Polycythemia occurs if an animal has too many red blood cells. Polycythemia causes the blood to become too thick which can impair the ability of the heart to deliver oxygen throughout the body.

• Red Blood Cell Count - RBC (6.1-11.9). The Red Blood Cells (RBC) measures the number of circulating red blood cells. The RBC may increase with stress. 
• Hematocrit - HCT (29.0-50.0). The HCT measures the percentage of red blood cells in the blood to help detect anemia and dehydration. HCT may increase with stress.
• Hemoglobin - HGB (9.3-15.9). Hemoglobin delivers oxygen to the cells and tissues of the body. If your feline has anemia, she will suffer from symptoms related to lack of oxygen.

Your vet should share these results with you when you take your feline in for a wellness checkup (or any bloodwork). It's important to discuss any variances in the results from year to year and any extremes in values. Many vets like to get bloodwork to establish a baseline for future visits. Vets like to have CBC done to better equip them to determine the overall health of your cat. The CBC can help determine if an infection is present and differentiate if it is viral, bacterial, or parasitic (some vets will do different tests to determine the type of bacterial infection to better treat with the appropriate antibiotic.) A CBC can also diagnose or help confirm if other disorders are present, such as allergies, autoimmune diseases, anemia, leukemia, and others.

Resources

Cotter, Susan M. Red Blood Cells of Cats. MERCK Manual Veterinary Manual. 2019. https://www.merckvetmanual.com/cat-owners/blood-disorders-of-cats/red-blood-cells-of-cats.

Foster, Race, DVM. Blood Cells & Complete Blood Counts (CBC) in Animals. PetCoach. 2019. https://www.petcoach.co/article/blood-cells-complete-blood-counts-cbc-in-animals/.

Giese, Melissa. White Blood Cells in Dogs and Cats. Illinois College of Veterinary Medicine. July 12, 2015. https://vetmed.illinois.edu/pet_column/white-blood-cells-in-dogs-and-cats/.

Ruotsalo, Kristiina. Complete Blood Count. VCA Hospitals.com. 2015. https://vcahospitals.com/know-your-pet/complete-blood-count. 

Superchem Blood Test. Vetstreet.com. November 4, 2011. http://www.vetstreet.com/care/superchem-blood-test.

Blood Analysis and Testing. ANTECH Diagnostics. 2008. EDP200FEMB.

Bloodwork Meanings and Reference Ranges. The Cat Practice. 2019. http://www.thecatpracticepc.com/documents/BloodworkMeaningsrevised.pdf.