Educational Articles

Dogs + Diagnosis

  • Many problems can lead to vomiting, some easier to diagnose than others. Simple acute vomiting with no other clinical signs may not require diagnostic testing, but if vomiting is ongoing or your pet is showing other clinical signs, then baseline diagnostic testing including complete blood count (CBC), biochemistry profile, urinalysis, and fecal testing may be recommended. Additional diagnostic testing may be required depending on the results of these tests.

  • Pets that feel weak often have difficulty getting to their feet and move slowly or unsteadily. Other signs include shaky muscles, fainting, or collapse. You may find your pet does not want to exercise, seems dull, and does not respond when you call.

  • Weight loss in dogs can be caused by many conditions including inadequate intake to meet energy requirements, poor quality nutrition, and many different medical conditions. Testing for weight loss starts with a thorough history and physical exam. If the cause of weight loss is not clear, then screening tests including a CBC, biochemistry, urinalysis, and fecal tests are performed to further investigate. Based on the results of these tests, more specific diagnostic tests such as imaging, bile acids, or ACTH stimulation may be needed to determine the reason for the weight loss.

  • Diagnosis of hypothyroidism includes a complete blood count, biochemistry profile urinalysis and thyroid-related hormones. Anemia, elevated cholesterol and mild liver enzymes are supportive of a diagnosis of hypothyroidism. Assessing thyroid hormone output can be difficult as other diseases and medications can suppress blood thyroxine levels. A combination of measurements of total T4, free T4 by equilibrium dialysis, and thyroid stimulating hormone (TSH) is generally used to confirm a diagnosis. Measurements of total T4 may be used to monitor thyroid levels if your dog requires hormone replacement therapy.

  • Trypsin-like immunoreactivity (TLI) is a blood test that measures the amount of a pancreatic proenzyme called trypsinogen. This measurement correlates with the amount of pancreatic enzymes released into the intestine to aid in digestion. A low measurement indicates exocrine pancreatic insufficiency. Concurrent pancreatitis or tests done shortly after a meal may temporarily increase this measurement to a normal value (false negative).

  • Ultrasound uses the reflection of sound waves to generate an image of internal structures allowing for identification of masses, pregnancy diagnosis, abnormal heart function and muscle size, abnormalities of the orbit, and abnormal appearance of abdominal organs. It cannot be used to identify abnormalities in areas of air such as the lungs, or areas surrounded by bone. B-Mode generates a 2-dimensional image, while M-Mode can be used to trace structures in motion and is often used in ultrasound evaluation of the heart. Doppler can be used to identify speed and direction of fluid flow such as blood flow. Anesthesia is generally not needed unless tissue biopsies are planned. Shaving of fur is recommended to allow best contact of the probe with the skin to produce the most diagnostic images. Ultrasound results can be analyzed in real time; however, assessment by a radiologist may take several days. Ultrasound is an invaluable tool to detect problems in a non-invasive fashion.

  • Urinalysis is an important part of any comprehensive workup or health screen as it provides information on the urinary system including the kidneys and bladder and also can support diagnosis of metabolic disease such as diabetes mellitus. Urine collection methods include cystocentesis, catheterization, or mid-stream free flow, each of which has their own pros and cons. Urine samples are assessed using the following parameters: appearance (color and turbidity), concentration assesses how the urine has been concentrated by the kidneys, urine dipsticks (assess pH, glucose, protein, blood, ketones, urobilinogen, and bilirubin), and microscopic exam of sediment (may reveal the presence of abnormal cells including red blood cells, white blood cells, and tissue cells or crystals). A cytological preparation of sediment may be recommended to look at tissue cells in more detail.

  • Cortisol is a stress hormone that is excreted from the body in the urine. Creatinine is a product of muscle metabolism and it is normally lost in the urine at a relatively steady rate. The ratio of cortisol to creatinine in the urine can be used to account for the effect of urine concentration. Urine cortisol/creatinine ratio is usually evaluated in animals suspected of having Cushing's disease. This test involves the collection of a single urine sample, taken first thing in the morning. Ideally, this sample should be collected at your home, to minimize the effects of stress.

  • The presence of protein in urine is called proteinuria. This may indicate that the kidneys are not working properly. In some situations, it may even be a sign of kidney failure; however, bleeding or inflammation in the urinary system is a far more common cause of proteinuria. If proteinuria is not due to inflammation or bleeding in the urinary system, then it is more likely to be a sign of true kidney disease. Your veterinarian may recommend further testing if the urinalysis reveals inflammation or bleeding.

  • The urine protein:creatinine (UPC) ratio is a simple test that measures how much protein is being lost through the kidneys. Creatinine is a substance that appears in the blood as the result of muscle activity and is excreted by the kidney at a constant rate. The urine protein:creatinine ratio measures whether the excretion of protein is greater than expected when compared to the excretion of creatinine. Before the protein:creatinine ratio can be interpreted, two other measures of kidney function should be taken. These are blood urea nitrogen (BUN) and serum creatinine. In order to make a definitive diagnosis of kidney disease, repeat tests of protein:creatinine ratio and urinalysis on at least three consecutive urine samples taken at 2-week intervals is recommended.