Veterinary care should include diagnostic tests to determine the underlying cause of the diabetes and help guide subsequent treatment recommendations. Diagnostic tests are needed to recognize DM and exclude other diseases. These tests may include: Complete medical history and physical examination. Particular attention will be given to your assessment of changes in eating and elimination activities. Changes in weight or general behavior will also be noted. The abdomen will be carefully palpated (probed by touch) to feel for changes in the size of the abdominal organs.
Analysis of the urine. This will allow your veterinarian to check for the presence of glucose or ketones (an acid produced by the body when insulin is absent), as well as for signs of urinary bladder infection, a common complication of DM.
Biochemical analysis of the blood. This test will allow confirmation of elevated blood glucose (sugar) concentrations. Elevated blood glucose is the hallmark of DM. In addition, these tests will allow some assessment of kidney and liver function and of the acidity (pH) of the blood. Results of biochemical analysis may reveal complications of DM and can often reveal the presence of concurrent diseases as well.
Blood glucose concentrations may be measured more than once. Stress, a recent meal or certain drugs may cause mild to moderate elevations in blood glucose in the absence of DM. Persistent elevations in blood glucose, particularly after a fast, often suggests DM.
Additional tests may be recommended on an individual basis. These tests include:
Glycosylated hemoglobin, the product of the cumulative effect of blood glucose on red blood cell hemoglobin, is measured by sending blood to a special laboratory. This test allows the veterinarian to get an idea of what the blood glucose concentrations are like over the course of several days instead of at one brief instant. The response of the patient to treatment must be followed.
Serum fructosamine measurements are used in the same way that glycosylated hemoglobin measurements are. Fructosamine, is the product of the effect of blood sugar on the blood protein albumin. This level is generally monitored every 3 to 6 months after diabetic control is attained.
Urine culture may confirm the presence of a urinary bladder infection, prove what type of bacteria is causing the infection and tell the veterinarian which antibiotics should be effective in treating it (and which ones will not).
Complete blood count (CBC) can discover anemias (too few oxygen-carrying red blood cells), abnormal platelet numbers (too few or too many blood clotting cells) and abnormal white blood cell counts (too few or too many infection-fighting cells). Infections are a common complication of DM.
Abdominal radiographs (X-rays) may be requested to rule out changes in size of organs like the liver or kidneys or to look for evidence of abdominal tumors. Kidney disease, intestinal disease, disease of the adrenal gland or certain abdominal tumors may be present and have signs very similar to DM.
Abdominal ultrasonography uses sound waves to evaluate the contents of the abdominal cavity. A specialist often performs the test in which the fur is shaved and a probe is held against the abdomen (this is the same test given to many pregnant women to visualize the fetus). This test can reveal many of the same things as abdominal radiographs, but provides a more detailed examination along with views of the inside of organs rather than just the shadow of the organ.
Specific endocrine tests including an ACTH stimulation test, low and/or high dose dexamethasone suppression test, or urine cortisol/creatinine ratios may be requested if hyperadrenocorticism is suspected (generally in older cats). Hyperadrenocorticism complicates both the diagnosis and treatment of DM.