Blood tests

Analysis of blood samples can help determine the state of your pet’s health and assist your veterinarian in diagnosis of illness or injury. There are some blood tests that your veterinarian may want to perform during your pet’s regular checkups. Minimal risk is associated with performing the tests, and the information gained is invaluable.

Blood testing is commonly used to help diagnose disease in animals. It can also help determine the state of your pet’s health during regular check-ups. Although a complete blood count (CBC) or a chemistry profile can be performed separately, these tests are frequently done at the same time. When the results are interpreted together, they provide a good overview of many of the body’s functions. Your veterinarian will combine this information with physical examination findings, medical history, and other information to assess your pet’s health status and determine if additional testing should be recommended.

Complete blood count

The CBC involves counting the numbers of different types of cells in the blood. This can be very useful in many ways, including identifying if the pet is dehydrated, anemic (having inadequate numbers of red blood cells), or dealing with an infection. The CBC measures the numbers of different types of cells but an examination of a blood smear provides additional information about the form of the red blood cells, white blood cells, and platelets. The CBC results may list abbreviations for the various tests included in a CBC:

• HCT is the hematocrit, which indicates how many red blood cells are present. A low HCT might indicate anemia, and a high HCT could indicate dehydration.
• Hgb is the quantity of hemoglobin within each red cell, which can help determine how well the red blood cells will carry oxygen to the body’s tissues.
• WBC is the total white blood cell count. Certain types of white blood cells may increase in number when there is infection or inflammation in the body. If the total number is low, it could mean several things, including a severe infection that has overwhelmed the body, or a bone marrow problem that is limiting production of white blood cells. There are several different types of white blood cells, which respond to different events in the body. EOS (eosinophils) are white blood cells that tend to increase in number when the body is dealing with an allergy or some parasites.
• PLT is the quantity of platelets (also called the platelet count). Platelets are involved in the body’s blood clotting process.

Chemistry Profile

The chemistry profile measures a variety of chemicals and enzymes (proteins that are involved in the body’s chemical reactions) in the blood to provide very general information about the status of organ health and function, especially of the liver, kidneys, and pancreas. The chemistry profile also shows the patient’s blood sugar level and the quantities of important electrolytes (molecules like sodium, calcium, and potassium) in the blood.

Chemistry values that help provide information about the liver include ALKP (alkaline phosphatase), ALT (alanine aminotransferase), AST (aspartate aminotransferase), and TBIL (total bilirubin).

Chemistry values that help evaluate the kidneys include the BUN (blood urea nitrogen) and CREA (creatinine). Of these two values, creatinine is a more sensitive indicator of kidney damage. There should be concern even if it’s only slightly elevated.

AMYL (amylase) and LIP (lipase) are enzymes produced by the pancreas.

To perform a CBC and chemistry profile, your veterinarian must first obtain a small blood sample from your pet. This may take only a few seconds if the patient is well prepared and the veterinary team has established a safe and comfortable environment, taking into consideration your pet’s preferences. For patients that are very frightened, your veterinarian may want to prescribe medication to minimize your pet’s anxiety for you to administer at home prior to attempting to draw blood. If your pet is frightened or panicked, being physically restrained will only intensify their fear and make the next visit or even at home care more difficult. Plus, the fear your pet is experiencing can also affect the blood sample test results. In some cases, your veterinary team might suggest, in conjunction with event medications, working with a qualified animal trainer to help teach your pet become more comfortable with veterinary care.

Some veterinary practices have in-house blood analysis equipment, so they can perform a CBC and chemistry profile in the practice and have results the same day. Other surgeries send blood samples to an external laboratory for these tests to be performed. If an external laboratory is used, results are generally available within 1 to 2 days.

Following a meal there are changes to a number of the constituents of blood and these may affect the results of a chemistry profile, your veterinarian may recommend that your pet is fasted for 8 to 12 hours before blood is drawn. In most cases, water can still be offered. Please let your veterinarian know if this temporary fast will be a problem for you or your pet.

You must also tell your veterinarian about any medications or supplements that your pet is receiving, as some products can alter the results of a chemistry profile.

When a pet presents with clinical signs indicating an illness, a CBC and chemistry profile is often performed very early during the diagnostic process. Even if results of this initial testing are all “normal”, this information can rule out a variety of medical conditions. If results of a CBC and chemistry profile are abnormal or inconclusive, your veterinarian may recommend additional testing to get closer to a diagnosis.

A CBC and chemistry profile is also part of routine blood work that may be performed before a pet undergoes general anesthesia for a surgical procedure. If test results are abnormal, your veterinarian may recommend additional precautions to help ensure your pet’s safety during the procedure. Your veterinarian may also recommend postponing the procedure or choosing an alternative treatment option.

Depending on your pet’s age and health history, additional tests (such as thyroid testing or urinalysis) may also be recommended as part of wellness testing. For elderly or chronically ill pets, your veterinarian may recommend blood work more frequently. Wellness blood work screens for many medical conditions, including diabetes and kidney disease. In many cases, early diagnosis and management can improve quality of life and the long-term prognosis for pets with chronic illnesses.

Performing a CBC and chemistry panel poses minimal risk for your pet, and in many cases, the information your veterinarian gains from this testing is invaluable.