Laboratory and Blood Tests

The results of blood tests will help guide treatment, as they can help diagnose diseases such as diabetes, kidney failure, and urinary tract infection. Most blood samples will be sent to an outside laboratory, but we do have the ability to run the most common tests in-house for sick patients, since they will benefit from immediate results. Below we discuss some of the tests often seen on a routine lab panel.

Many of these blood values are affected by multiple organs in the body. It is important to evaluate a change in one value with respect to all other blood test findings, as well as the overall health of your pet.

Complete Blood Count (CBC)

White blood cells (WBC): These cells are critical for the immune system to fight off infection and inflammation. A mild elevation may sometimes be due to stress, but a large increase can be due to infection or cancer.

Hematocrit (HCT): This is a measure of red blood cells, which carry oxygen to the rest of the body. A drop in this number indicates anemia, which has many causes. An elevation can be due to dehydration.

Platelet (PLT): These cells are needed to form blood clots. When platelets drop too low, a pet may no longer be able to form the clot needed to prevent bleeding after an injury.

Chemistry

Albumin: This protein is made by the liver and helps maintain blood volume. A low albumin can sometimes indicate inflammation, liver or kidney disease, cancer, or bleeding.

Globulin: This protein is important in inflammation and fighting off infection.

ALT: An elevation of this liver enzyme may indicate liver damage or liver disease.

ALP: An elevation of this liver enzyme can be due to liver disease, but it may also be influenced by problems in other areas of the body such as Cushings disease or hyperthyroidism. Puppies normally have a high ALP due to active bone growth.

Urea Nitrogen (BUN): This is one of the kidney values. When this value is increased, it most often indicates kidney disease, but an elevation can also be due to dehydration, urinary obstruction, or liver disease.

Creatinine: This measures kidney function more directly than BUN. While a mild elevation can be due to dehydration, it is most often due to kidney disease or failure.

Glucose: This is the blood sugar level. While a slight increase can be due to stress, a very high number most often indicates diabetes mellitus. Too low of a value can be seen in younger dogs not eating frequently enough, or in older dogs with a tumor. An extremely low glucose can cause seizures.

Calcium: Changes in calcium can be due to kidney disease, a tumor, or hyperparathyroidism. An elevation may be grounds for follow-up testing depending on your pet’s symptoms.

T4: Also known as thyroxine, this is a thyroid hormone. Low values in dogs could indicate hypothyroidism, but may also be due to other non-thyroidal illnesses. High T4 in a cat indicates hyperthyroidism.

Sodium, Potassium, and Chloride: These electrolytes can be outside their normal range due to vomiting, kidney disease, Addison’s disease, and more. A severe increase or decrease in potassium can affect heart function.

Urinalysis

Specific Gravity: This indicates the concentration of urine, which is affected by kidney function, as well as how much water your pet recently drank.

Glucose: There should normally be no glucose in the urine, and a positive result may indicate diabetes.
Ketones: This is also a marker for diabetes, and shows a more advanced stage of the disease.

Crystals: These can act as a precursor for bladder stones. There are several kinds of crystals that can form, some of which may be related to a urinary tract infection. If your pet has a persistently high crystal count, your veterinarian may discuss a diet change.

Bacteria: Usually indicate a urinary tract infection. Repeated UTIs may warrant a urine culture, a more extensive test in which the bacteria are allowed to grow and multiply in the laboratory, and then tested against different antibiotics. This allows us to determine which antibiotic may be the most effective treatment.

Protein and UPC: A high protein reading may trigger a urine protein: creatinine ratio (UPC) test. If the UPC is elevated, this may indicate a particular type of kidney disease called glomerulonephritis.

ProBNP

This test measures a protein level that increases with stretch and stress of the heart muscle. An abnormal result indicates a high likelihood of heart disease. This test may be recommended based on our exam findings. It is also included in our pre-anesthetic screening for all cats who will be undergoing surgery.