Cystocentesis is a common veterinary procedure that involves collecting a sterile urine sample directly from an animal’s bladder. This method minimizes the risk of contamination that can occur with other collection techniques, such as mid-stream collection or catheterization. Obtaining a clean sample is important for accurate diagnosis of various conditions affecting the urinary system.
Reasons for Performing Cystocentesis
Veterinarians frequently perform cystocentesis to diagnose urinary tract infections (UTIs). A sample obtained via cystocentesis is sterile, allowing for accurate urine culture and sensitivity testing. This identifies the specific bacteria causing an infection and determines which antibiotics will be most effective.
The procedure also helps identify bladder stones, known as urolithiasis, and crystals within the urine, called crystalluria. These can indicate underlying metabolic issues or predispositions to stone formation. Cystocentesis can also assess other bladder conditions, such as inflammation or the presence of abnormal cells. In some situations, it may serve a therapeutic purpose by decompressing an overly full bladder in cases of urinary obstruction, providing immediate relief to the animal.
What to Expect During the Procedure
During a cystocentesis, the pet is gently restrained, often lying on their back or side. The veterinarian locates the bladder, typically using an ultrasound machine. Ultrasound guidance provides a real-time image, allowing for precise needle placement and increased safety.
Once the bladder is located, a small, sterile needle attached to a syringe is quickly inserted through the abdominal wall directly into the bladder. The veterinarian then gently draws urine into the syringe. The process is generally very quick, often taking only a few seconds, and most animals experience minimal discomfort, comparable to a routine injection. After the sample is collected, the needle is swiftly removed, and the urine is transferred to a sterile container for laboratory analysis.
Potential Risks and Safety
Cystocentesis is generally a very safe procedure when performed by experienced veterinary staff, though rare complications can occur. The most common minor side effect is temporary blood in the urine (hematuria), which usually resolves on its own if a tiny blood vessel is nicked during needle insertion.
More severe complications are extremely uncommon but can include accidental puncture of an organ other than the bladder, such as the intestines, or, in very rare instances, leakage of urine into the abdominal cavity, which could potentially lead to infection. Bladder rupture is also an extremely rare risk, typically only occurring if the bladder is severely distended and diseased. The procedure might not be recommended for animals with bleeding disorders, those that are extremely agitated and cannot be safely restrained, or those with a very small or empty bladder, as these conditions increase the potential for complications.
Interpreting the Urine Sample
Once the sterile urine sample is collected, it is sent to a laboratory for comprehensive analysis, including urinalysis and urine culture with sensitivity testing. Urinalysis evaluates the physical and chemical properties of the urine, such as its color, clarity, specific gravity (concentration), and pH.
The urinalysis also checks for the presence of various components like protein, glucose, blood, cells (red and white blood cells), crystals, and bacteria. If a bacterial infection is suspected, a urine culture identifies any bacteria present, and sensitivity testing determines which antibiotics will be effective. These detailed test results provide veterinarians with precise information for accurate diagnosis and effective treatment.