Urethral Catheterization Procedure in Animals

Urinary bladder catheterization involves the passage of a man-made (usually polypropylene) urinary catheter via urethra. A urinary catheter is a long, thin tube that is inserted into the bladder through the external urinary opening. A syringe is attached to the external opening of the catheter, and the urine is aspirated,3 (a procedure called cystocentesis). Females can be catheterized with the aid of a vaginoscope.4 Locating the urethral opening in some animals such as ferrets is a challenge in both males and females. Male ferrets present more often in an emergency situation due to urethral obstruction from prostatic disease caused by adrenal gland problems or cystic stones.5

Advantages of the procedure include giving diagnostic information about urinary tract obstruction, allowing urine collection without the need to await spontaneous voiding; allowing monitoring urine output; facilitating diagnostic imaging procedures such as contrast radiography, and to facilitate relief of lower urinary tract obstruction.2 These include the need of heavy sedation or general anesthesia in many animals (essentially in cats and female dogs.), equipment and time costs, the risk of contamination of samples and urinary bladder with bacteria from the external genitalia, and finally the risk of trauma caused by passage of the catheter.

When an animal has a urethral obstruction, it is impossible to urinate, and this is a life-threatening situation. Generally, a pet owner should immediately seek veterinary care to relieve obstruction. Urinary catheterization is not without risk. While passing a urinary catheter is often the only option when a cat becomes obstructed, damage to the urethra may occur which leaves the animal more likely for repeated obstruction in the future. Immediate blockage may occur due to urethral swelling, and later blockage may occur due to the formation of scar tissue that forms after a urethral trauma.1

Indwelling urinary catheters are placed after major surgical procedures to assess urine output. The routine use of catheters after surgery allows easy nursery in the first 12-24 hours, avoids urine soaking of the animal, and avoids distress in animals that need to urinate but unable to go outside. They may be placed in animals with spinal disease that are unable to urinate, to divert urine after urethral surgery or trauma, or after an episode of urethral obstruction in male cats.

References

  1. Homeopathic care for cats and dogs: small doses for small animals. Donald Hamilton
  2. Textbook of veterinary medical nursing. Carole Bowden, Jo Masters
  3. Tasks for the veterinary assistant. Paula Pattengale
  4. Textbook of veterinary surgical nursing. Carole Martin, Jo Masters
  5. Exotic animal medicine for the veterinary technician. Bonnie M. Ballard, Ryan Cheek