For many pet owners, it may seem as if their veterinarian is speaking a different language when discussing their pet’s needed diagnostic tests and health status. Similar to human physicians, veterinarians use a variety of diagnostic blood tests to evaluate your pet’s overall health. Additionally, blood tests can help identify the presence of disease like diabetes, or a toxin exposure. Many blood tests can be completed within a few minutes at your veterinary hospital while other tests may require an outside laboratory to complete the evaluation. Our Animal Emergency Care team wants to demystify your questions about blood work, so we answer common questions and discuss reasons blood work is a vital component of your pet’s health evaluation.  

What is a complete blood count in pets?

A complete blood count (CBC) is a routine test used to evaluate the amount and types of cells circulating in your pet’s bloodstream. A small amount of blood is collected from your pet and placed in a tube containing an anticoagulant. The blood sample then is placed in an automated blood analyzer to determine changes in the amount, shape, and size of blood cells which provide clues about your pet’s overall health, hydration status, immune function, infection status, and blood clotting ability. There are three main types of blood cells:

  • Red blood cells (erythrocytes) Red blood cells (RBCs) are responsible for the red color of your pet’s blood and carry oxygen throughout their body. Elevations in RBCs can be an indication of dehydration or certain bone marrow disorders. Decreased RBCs may indicate anemia from certain diseases or bleeding. 
  • White blood cells (leukocytes) Five types of white blood cells (WBCs) fight infection, including bacteria, viruses, and foreign materials. Changes in WBC levels can be an indication of severe inflammation, cancer, or bone marrow diseases. 
  • Platelets (thrombocytes) — These cells are vital for blood clotting and preventing excessive bleeding. Decreased platelets could be an indication of a congenital clotting disease, heatstroke, immune disorder, or other underlying disease. 

What is serum biochemistry blood testing in pets?

A serum biochemistry blood test is a chemical analysis of the yellow liquid portion of clotted blood, also known as serum. Similar to a CBC evaluation, the liquid sample is placed in an automated blood analyzer machine. Certain components such as proteins, enzymes, and hormones are evaluated for information about your pet’s organ function, digestive health, diseases, and toxin exposure. Numerous types of serum biochemistry tests exist and common parameters examined include:

  • Liver enzymes — Numerous enzymes are used to evaluate liver function including alkaline phosphatase (ALP) and alanine aminotransferase (ALT). Elevations in these enzymes may indicate stress, inflammation, organ damage, or toxin exposure.
  • Proteins Proteins including albumin and globulin provide information about organ function as well as about the presence of infection and some cancers. 
  • Kidney tests — Elevations in blood urea nitrogen (BUN) and creatinine indicate decreased kidney function and are used to determine renal failure severity.
  • Electrolytes — Changes in electrolytes including sodium and potassium can cause medical problems such as dehydration, digestive problems, and kidney disease. Electrolyte levels also are monitored when your pet is placed on intravenous fluid therapy and certain medications. 
  • Pancreatic enzymes — Enzymes including amylase and lipase may increase with pancreatic inflammation which may occur after ingestion of a fatty meal.

When does my pet need blood work?

Blood work is a minimally invasive cost-effective diagnostic tool that can provide a voluminous amount of information about your pet’s overall health. Annual or more frequent blood work is recommended in middle-aged and senior pets to monitor age-related organ changes and early disease signs. Other reasons your veterinarian may recommend blood work include:

  • Annual wellness examinations — Annual blood work can help identify underlying problems that may not be obvious during a physical examination. Starting blood work when your pet is young also will establish baseline values for comparison as they approach their grey muzzle years.
  • Presurgical evaluation — Before surgery, your veterinarian will run blood tests to ensure your pet’s liver and kidneys are healthy enough to process anesthetic agents. 
  • Medication safety — Serum biochemistry tests to evaluate your pet’s liver and kidneys are critical before starting a new medication such as a non-steroidal anti-inflammatory. Most medications are metabolized through the liver or kidneys and abnormal blood values will prevent the use of certain drugs. 
  • Disease or injury — Some illnesses or injuries such as internal bleeding after trauma may not be obvious during a physical examination. A CBC will provide clues that internal bleeding is present and a serum chemistry test will help identify organ damage or disease presence.  

Call your family veterinarian to schedule your pet for their annual blood work evaluation. If your pet needs help after hours contact Animal Emergency Care and bring them in for evaluation—which will most likely include blood work—and treatment. #AECprevents

Sources:

https://www.merckvetmanual.com/special-pet-topics/diagnostic-tests-and-imaging/laboratory-tests-routinely-performed-in-veterinary-medicine

https://vcahospitals.com/know-your-pet/complete-blood-count

https://veterinarypartner.vin.com/default.aspx?pid=19239&id=4952036

https://vcahospitals.com/know-your-pet/serum-biochemistry

https://www.merckvetmanual.com/special-pet-topics/diagnostic-tests-and-imaging/types-of-veterinary-medical-tests?query=cbc

https://www.aaha.org/aaha-guidelines/life-stage-canine-2019/diagnostic-testing-for-each-life-stage/