Bloodwork

Written by Kathy Dvorak

Why do we do blood work? Simply stated, because our dog cannot describe symptoms to let us know what might be wrong. Diagnosing an illness in a dog, as in humans, can be difficult and often requires many laboratory tests including blood work. Blood work is also important to establish a "baseline" for health care (i.e. comparison of our dog when (s)he is well versus when a situation arises). And last, but certainly not least, it is used to monitor dog's that are on anti-convulsant drugs.

The Hemogram or Hematology test, also referred to as Complete Blood Count, or CBC, is an essential component of the initial diagnostic evaluation for almost any type of illness. It provides an inside look at both the cellular and fluid components of the blood itself. Abnormalities can indicate the presence of a disease, inflammation, stress or an inability to fight infection.

Red Blood Cells (RBC's) are responsible for carrying oxygen throughout the body.
White Blood Cells (WBC's) are the body's primary means of fighting infection.
Platelets play an important role in blood clotting and are critical in helping the body to stop bleeding. They are the smallest cells in the blood.
Noncellular Elements measured in the blood include proteins and other substances within the fluid portion of an unclotted blood sample.

The blood, one milliliter (ml), is drawn into a tube for a Hemogram (CBC). The tube contains an anticoagulant which is a chemical that prevents blood from clotting. The contents of the tube can also be referred to as plasma, which is blood fluid with clotting factor proteins intact.

The Chemistry panel or Blood Chemistry test or Serium Chemistry test is often included along with the Hemogram but it is wise to ask just to be sure. It provides an inside look at a large amount of information pertaining to different major vital organ functions. Abnormalities can point to damage or dysfunction involving the kidneys, liver, muscles, glandular or digestive functions, and various other aspects of body metabolism.

The fluid that remains after the fluid portion of a blood sample has been allowed to clot is known as serum. This is what is used for the Chemistry panel.

Two other very important tests to mention here are:

Phenobarbital (PB) level test and Potassium Bromide (KBr) level test. If your dog is on either or both of these anti-convulsant drugs, these tests will play an important role in the management of your epileptic dog.

The one really important thing to point out is, PB and KBr may play havoc with some of your dogs test results. It is so very very important to work with your veterinarian in understanding the different levels and what they mean. A higher than normal Alanine aminotransferase (ALT) or Alkaline Phosphatase (ALKP) level may be acceptable in a dog taking anti-convulsant drugs. Comparing your dog's numbers to another dog in your household is unfair especially if the one is on anti-convulsant drugs. A better way to monitor this might be creating a spread sheet and actually tracking the results of each dog. Knowledge of what the blood work indicates is your key in identifying a situation before it is really a problem.

Instead of listing each of the different components of the blood work and what it means, I would like to refer you to some very good web sites that provide excellent explanations of this. They follow below:

http://www.ighawaii.com/naturally/newsletter/lab.html
http://www.executec.com/labtest.htm
http://www.cardogz.com/columns/vet/archive/1998_12_30.shtml

References:

Gronowski PHD, Ann M.
Lab Work - A guide to common blood tests
Dog Fancy Magazine

IDEXX Laboratories, Ltd
Facts about Blood Testing

Seigal, Mordecai, editor, Faculty and Staff, School of Veterinary Medicine
UC Davis School of Veterinary Medicine Book of Dogs
Complete Medical Reference Guide for Dogs and Puppies
HarperCollins Publisher, NY 1995

Page last update: 05/19/2011