Laboratory Diagnostics

Laboratory tests are an essential part of every veterinary practice. They aid us in diagnosing illnesses in cats that are sick, and they help us confirm that a cat that appears healthy on physical examination is indeed healthy. As in human medicine, early detection of health problems the key to keeping cats healthy. Practicing prevention is always better than treating a disease already present. In the long run, preventive medicine improves quality of life and is more cost effective than waiting for problems to appear. A well-educated and proactive owner is the first step in optimal cat care.

A thorough physical exam and accompanying diagnostic tests may be recommended in middle aged and in elderly cats, to ensure that the early stages of disease are discovered and appropriate preventive measures and treatment plans instituted. The most common diagnostic tests performed include:

Complete blood count

In geriatric patients, anemia is not an uncommon finding. Red blood cell morphology can help determine if the anemia is acute, chronic or related to a neoplastic (cancerous) condition. The total white count is also noted, and increases may indicate inflammatory or infectious conditions.

Biochemical profile

The biochemical profile is a very valuable test. Information about the liver, kidneys, pancreas, blood sugar, and electrolytes is obtained through this important test.

Thyroid testing

Hyperthyroidism is a very common problem in older cats. The most common signs of hyperthyroidism are increased appetite and weight loss.


Analysis of the urine can help detect underlying urinary tract infection, kidney problems and diabetes. If the urinalysis is suggestive of a urinary tract infection, a urine culture may be recommended to confirm the infection and determine which antibiotics would be the best to prescribe.

Fecal examination

Since gastrointestinal parasites may be debilitating, a yearly fecal analysis is recommended. Additionally, some parasites have the potential to be transmitted to people, re-enforcing the value of yearly fecal exams. Routine fecal floatation is recommended, with specific tests for the protozoan parasite Giardia performed if necessary.

FIV (feline immunodeficiency virus) and FeLV (feline leukemia virus) testing

Both of these viral diseases may cause suppression of the immune system and can contribute to many other systemic illnesses. In cats that are at risk of exposure to these viral diseases (i.e. outdoor cats or cats that have contact with other cats) routine blood testing is recommended. If the viral status of a cat is unknown, testing is also advised. Cats who have previously tested negative and have had no possible exposure to other cats may not need this test.

laboratory test for cats in New York

Depending on physical examination and initial labwork findings, common additional testing might include:

Blood pressure measurement

Hypertension (high blood pressure) is an often overlooked and underdiagnosed problem in veterinary medicine. Usually, hypertension is associated with other disease conditions such as kidney failure and hyperthyroidism.

Aspiration of skin masses

A common finding on the physical examination of older cats is small masses in the skin. Many times these are benign tumors or cysts that grow slowly and rarely cause problems. However, cats do have a higher incidence of malignant skin tumors than do dogs. Because of this, it is usually recommended that skin tumors on cats be aspirated (a needle is inserted into the mass) and the recovered cells evaluated microscopically for evidence of malignancy. The size and location of all masses should be recorded in the medical record, so that changes in previous masses or the development new masses can be noted.


Radiographs (x-rays) may be advised based on the initial tests or physical exam findings. Chest radiographs are part of a cardiac work-up if a heart murmur is found and as a screening test for cancer. Abdominal radiographs might be needed if organ dysfunction is suspected or organ enlargement or masses is detected during the physical examination.

Cardiac (heart) evaluation

If there is indication of potential heart disease such as a newly discovered or a worsening murmur or a persistent cough, a more complete cardiac evaluation is indicated. Chest radiographs, an EKG and an echocardiogram will help better define the extent and cause of potential cardiac disease and whether treatment is necessary.

Abdominal ultrasound

Abdominal ultrasound offers a non-invasive method of visualizing masses and organs within the abdomen. Generally, more detail and structure can be obtained with an ultrasound than with radiographs.


Evaluating the stomach and initial part of the small intestines through the use of endoscopy is a valuable diagnostic tool. A common problem that some middle aged and older cats have is inflammatory bowel disease (IBD). Cats with IBD usually have vomiting and or diarrhea as symptoms, but sometimes present with weight loss as the only complaint. Endoscopy offers a relatively non-invasive method of obtaining gastrointestinal biopsies for establishing a diagnosis.