Merck Manual

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Pet Owner Version

Detecting Disorders of the Kidneys and Urinary Tract in Dogs


Sherry Lynn Sanderson

, DVM, PhD, DACVIM-SAIM, DACVIM-Nutrition, Department of Biomedical Sciences, College of Veterinary Medicine, University of Georgia

Reviewed/Revised Jun 2018 | Modified Oct 2022

Your veterinarian can diagnose many common problems with the urinary system by taking a history of how your dog has acted in the days prior to its becoming sick, performing a physical examination, and performing tests on the dog’s blood and urine. The history that your veterinarian takes might include information regarding changes in how much water your pet drinks, how often it urinates, how much urine it produces, how the urine looks, and how your pet behaves. Your veterinarian will also need information about what medications your pet has taken or is currently taking, your pet’s appetite and diet, changes in body weight, and previous illnesses or injuries.

When performing the physical examination, your veterinarian will feel your dog’s kidneys and bladder, examine its genitalia and, sometimes, its rectum. In both male and female dogs, examining the rectum allows your veterinarian to feel the urethra. In male dogs, it also allows your veterinarian to examine the prostate. If your pet has trouble urinating, your veterinarian may also want to perform a neurologic (nerve and brain) examination. There are many other tests a veterinarian might perform in the case of a urinary disorder. These include blood tests, blood pressure tests, urinalysis and other urine tests, x-rays, contrast x-rays (tests in which a special dye is given to outline the urinary tract on the x-ray), ultrasonography, biopsies, and cystoscopic tests. Cystoscopic tests involve inserting a small tube with a camera on the tip into the urethra. This allows the veterinarian to view the inside of the urethra and the bladder. Your dog will be anesthetized or given a tranquilizer for such a test.

Urinalysis is a laboratory test that evaluates urine. It is one of the most important tools a veterinarian can use to diagnose urinary tract problems. Many tests are performed as part of a urinalysis. These include urine specific gravity, which is an indication of how concentrated the urine sample is; color; turbidity or cloudiness of the urine; and pH (how acidic or alkaline the urine sample is). Urinalysis also tests for the presence of certain chemicals or substances in the urine, such as sugar, ketones (a byproduct of the body’s processing of fat), bilirubin (a pigment produced when the liver processes waste), blood, and protein. The urine sediment is also examined under a microscope to look for things such as red blood cells, white blood cells, other cells, bacteria, crystals, and renal casts (tube-shaped particles that come from the kidney). Urinalysis is best performed on fresh urine samples because delays can cause inaccurate results. If you collect a urine sample from your dog, keep the sample refrigerated and let your veterinarian know what time it was collected.

If a urinalysis finds protein in the urine, an additional urine test called a urine protein:creatinine ratio may be necessary. If your veterinarian suspects your dog may have a urinary tract infection, a bacterial culture may be performed instead of, or in addition to, urinalysis. Cystocentesis (removing urine directly from the bladder by use of a needle inserted through the abdomen) is the preferred way to collect urine for a bacterial culture.

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