Blood work explained

Blood work is a commonly used to diagnose disease or to pinpoint injury in animals.  It can help determine the state of your pet’s health during its annual physical exam. 

Complete blood count (CBC)

The CBC can determine if the pet is dehydrated, anemic, or has an infection.  Vets also use it to see if the animal’s blood clots normally.  It measures the quantity and quality of red blood cells, white blood cells and platelets.  The CBC tests results may show an abbreviation for the specific tests.  Below is a guideline that will help you interpret each of the tests:

HCT is the hematocrit, which indicates how many red blood cells are present. If the number is low, the animal is anemic. If it’s high, the animal most likely is dehydrated.

Hb is the quantity of hemoglobin, which can determine how well the red blood cells are carrying oxygen to the body’s tissues.

WBC is the white blood cell count.  These cells increase when there is an infection. However, if the number is low, it can mean that the animal has an overwhelming infection.

EOS are the quantity of eosinophils. These cells increase in numbers in allergic reactions  or if the animal has parasites

PLT is the quantity of platelets. If the number is low, it can indicate that the animal has problems with clotting blood.

Chemistry Profile

The chemistry profile determines the status of organ function, especially liver, kidney, and pancreas. It also indicate electrolyte status and glucose level.

*  Tests that evaluate the liver include ALKP (alkaline phosphatase), ALT (alanine aminotranferase), AST (aspartate aminotransferease), and TBIL (total bilirubin). If these tests are elevated, liver damage is suspected.

*  Tests that evaluate the kidney include BUN (blood urea nitrogen) and CREA (Creatinine).  Creatinine is the most sensitive indicator of kidney damage. There should be concern even if it’s slightly elevated. Sometimes can have a high BUN without having kidney disease.  This often occurs when the animal is on a high protein diet. 

*  AMYL (amylase) and LIP (lipase) are often elevated when the animal has pancreatitis.

*  Electrolytes  are checked for quantity and for proportion to other electrolytes.  They include Ca (calcium), CI (chloride),  K (potassium), Na (sodium), and PHOS (phosphorus.)  Electrolyte abnormalities can cause many types of health issues.  For example, low calcium levels can result in tremors or seizures. High calcium levels can indicate in a condition called tissue mineralization. This causes pockets of calcium crystals to form in organs and cause damage.

How it is done?

As with human, the most accurate blood tests are taken after the patient has fasted for 8 to 10 hours.  When blood is drawn too soon eating, the fats levels in the blood drastically skew the test results.

The two basic blood tests that are routinely performed are the CBC and the Chemistry Profile. Both tests require a relatively small amount of blood. The blood is taken through venipuncture. The most common spots for drawing blood are the cephalic vein, located in the animal’s arm, and the jugular vein, located in the neck. 

The sample is taken with a needle pulling the blood through a vacuum and then emptying directly into special tubes. The veterinarian will deposit the sample into a lavender top tube containing an anticoagulant, which keeps the blood from clotting. The blood sample taken for the Chemistry Profile goes into a red top tube that does not contain an anticoagulant, and is allowed to clot. Then it is placed into a centrifuge, where the blood is spun and the blood cells are separated from a yellow blood fluid called serum.

Each sample is then place in a machine that analyzes the blood components. The vet may perform this test the veterinary clinic or send to an outside laboratory.

What is it used for?

CBC and Chemistry profiles are usually recommended during an animal’s annual wellness exam.  With seniors or chronically ill pets, your vet may recommend blood work every six months. Early diagnosis and appropriate treatment of disease can increase the chances of recovery.

 Bloodwork is recommended before a pet goes under general anesthesia for a surgical procedure.  If test results show the surgery or anesthesia could put the pet at risk, , the veterinarian may postpone the procedure or choose an alternative procedure. For example, if the tests show that the patient has limited blood clotting ability, surgery would need to be cancelled.