Disorders of the urinary system in dogs are diagnosed with the help of blood and urine tests, as well as a physical examination by the veterinarian. The behavior of the dog in the days preceding the illness is also taken into consideration. The veterinarian may enquire about the fluid intake of the dog, the frequency of urination, the color and amount of urine produced, and the behavior of the dog while urinating. The details of the dog’s diet, recent changes in appetite or body weight, and the drugs the dog is taking at present, as well as those taken previously, may be required as well. Any injuries or illnesses the dog has had should also be reported.
The physical examination includes examining the external genitalia and the rectum in addition to feeling the bladder and the kidneys. By conducting a rectal examination, the veterinarian can feel the prostate gland in male dogs, while the urethra can be felt in both sexes. If the dog has difficulty in passing urine, a neurologic examination to test the involvement of the brain or nerves may be done.
The other tests done in order to diagnose urinary system disorders include testing the blood pressure, laboratory analysis of blood and urine, x-rays, and ultrasound scans. Sometimes contrast x-rays are taken after introducing a radioopaque dye to get a clearer image of the urinary tract. Cystoscopic tests and biopsies may also be done if necessary. In cystoscopy, a tiny camera attached to the tip of the cystoscope is inserted into the urethra to get a direct view of the urinary tract and the bladder. The dog has to be tranquilized or anesthetized during this procedure.
Urine analysis is the most important test for detecting the diseases of the urinary tract. A sample of the urine is tested for various parameters such as color, specific gravity, turbidity and pH value. The specific gravity indicates the concentration of the urine, while the pH value shows the acidity or alkalinity of the urine. Presence of abnormal substances in the urine is detected by urinalysis. They may include glucose excreted by the kidneys when the blood has high sugar content, ketones produced by the breaking down of body fat, and bilirubin excreted as a waste product of the metabolic activity of the liver. Traces of proteins and blood may also be present. The sediment of the urine is checked for bacteria, RBCs, WBCs and crystal deposits.
If a bacterial infection of the urinary tract is suspected, a culture and sensitivity test may be done to detect the pathogen causing it and to determine the suitable antibiotic drug to eliminate it. To check for infections within the urinary bladder, a sample of urine is drawn directly from the bladder by inserting a needle abdominally. This procedure is called cystocentesis. This avoids the contamination of urine sample in the urinary passage.