Ultrasound-Guided Cystocentesis in Dogs

If your dog is suddenly asking to go outside much more often to urinate but only passes small amounts each time, a urinary tract or bladder infection may be the cause. Other signs can include drinking more frequently and having urinary accidents in the home. Your pup should see a vet. Once the vet collects a urine sample from you dog through ultrasound-guided cystocentesis, and results come back from a laboratory, your veterinarian can make a definitive diagnosis and get her started on the proper antibiotic to clear up her infection and her discomfort.

There are four ways a veterinarian can collect a urine sample from your dog. If she voids her bladder on the examination table, the urine can be taken up with a syringe. Another method involves a veterinary assistant taking your dog for a walk to perform a free catch, which means slipping a pan under your dog as she urinates to collect a sample in midstream. A third method is to insert a urinary catheter into the bladder. The fourth and preferred method for urine collection iscalled cystocentesis. This procedure enables the veterinarian to collect a urine sample directly from the bladder, ensuring that the sample is not tainted by contaminants from the environment or from the lower urinary tract. Despite the lengthy name of ultrasound-guided cystocentesis, this procedure is extremely quick.

A cystocentesis is a needle tap of the bladder through the abdominal wall. Your dog will be positioned to lie on her back. Since she is not in her favorite locale, and lying on her back is a submissive position, she may protest this positioning far less than the test itself. Next, the veterinarian will palpate your dog’s abdomen to find her bladder and hold it in place. Alcohol sterilizes the area, and the vet inserts a needle attached to a syringe into her abdomen and straight into her bladder. As soon as the urine sample is drawn and the needle is pulled out, your dog will be eagerly prancing back into the examination room to rejoin you.

To help facilitate the process of finding the exact location of your dog’s bladder, an ultrasound may serve to guide the needle exactly where it needs to go. For a number of reasons, your veterinarian may not be able to readily palpate the bladder. If only a small amount of urine is in her bladder, for instance, it will be smaller and less prominent. If your dog is a full-figured gal, feeling the bladder through her abdomen will be difficult. By using an ultrasound, the veterinarian can visualize your dog’s bladder on a monitor screen while using the location of the wand to guide the needle. This allows for a single, quick and clean stick, and it also means less time that your dog has to remain immobilized on her back.

Once urine has been collected into the syringe, the veterinarian will impregnate a culturette with some of the urine. A bacterial culture and sensitivity will be performed on the urine, during which the bacteria are grown over a couple of days. This enables the laboratory technician to determine which type of bacteria is present so your veterinarian can make the appropriate antibiotic choice that will be most effective at combating the bacteria. The urine that remains in the collection syringe is injected into a urine sample tube for a urinalysis. This test detects the presence of white blood cells or red blood cells in the urine, which are indicative of an infection. The urinalysis also evaluates your dog’s kidney function and rules out other conditions that can present symptoms of increased thirst and urination.