Urinary Catheterization

Urinary catheters are placed for several reasons. Catheterization can be used to obtain a urine sample. Indwelling catheters can be placed in recumbent patients unable urinate on their own. Catheters are also placed in cases of urinary obstruction.

Summary of the Procedure:

Indications Obtaining a urine sample for urinalysis, determining patency of urethra, relief of urethral obstruction, biopsy of bladder mass, contrast radiography of urinary tract, long-term urine collection to facilitate nursing care and for renal function testing.
Limitations May introduce blood and epithelial cells into urine sample.

More difficult in female dogs.
Complications Urethral irritation, urinary tract hemorrhage, infection, ruptured bladder/urethra, incontinence (chronic catheterization).
Contraindications Rarely identified.
Supplies/instruments Flexible to rigid urinary catheters (3.5 French typically used for urethral obstruction in cats; 3.5-5 French as indwelling catheter in cats)

If indwelling catheter is being placed – a urine collection bag to attach to the catheter

Sterile lubricating jelly (+/- lidocaine)

60 mL syringes

Saline

Sedation, if needed.
Position Lateral or dorsal recumbency (male)

Sternal recumbency with hind legs extended over edge of table (female – typically need sedation).
Restraint Manual, sedation, anesthesia.

Use of lidocaine lubricant in the female dog is helpful.

Landmarks:

Male dogs:

  • To expose penis place middle finger between prepuce and ventral abdominal wall and index finger on ventral aspect of prepuce (or use index finger and thumb, respectively) and retract prepuce caudally while using other hand to push penis forwards.

 

Female dogs:

  • Identify clitoral fossa. Insert gloved, lubricated finger above the fossa into the vulva. The urethral papilla is palpated as either a small depression or bump on floor of the vulva, approximately 2-4 cm in depending upon the size of dog (which corresponds to the first to second joint of your finger).  Occasionally a ring sensation is felt, which marks the remnants of the vaginal septum. Alternatively an otoscope can be used to visualize the papilla which appears as a small rosette or orifice.

Details of the Procedure:

  • Determine the length of catheter necessary to enter the bladder and lubricate well with sterile jelly.
  • Gently wash penis/vulva.
  • To collect urine, or place an indwelling catheter, advance the catheter to pre-measured length. Urine usually flows through the catheter once it is in the bladder.
  • In male dogs slight resistance may be encountered just beyond the os penis and at the prostate.
  • In male cats, pull penis straight back in caudal direction (penile urethra is parallel to spine) to reduce the curvature of the urethra.
  • To relieve urethral obstruction in cats: if resistance is met during catheter placement, flush small amounts of saline while passing catheter to help relieve blockage.
  • Aspirate urine.
  • If leaving catheter in place, attach catheter to closed urinary collection system.

Video of a Feline Male Urinary Catheter Placement:

 

Video of Canine Male Urinary Catheter Placement:

Female Urinary Catheterization – Details of the Procedure:

  • See landmarks above.
  • Place patient in ventral recumbency, with hind legs over the edge of the table. A rolled towel under the caudal abdomen helps position the vestibule a bit more dorsally and also stabilizes the patient.
  • Clip long hair around vulva (do not clip down to skin as this will cause irritation)
  • Cleanse vulvar region.
  • Place a few mL of viscous lidocaine gel into the vestibule/vagina
  • Place gloved index finger* of non-dominant hand through the vulva and into vestibule, then palpate the ventral vestibule midline for a subtle raised area over a small opening. This is the urethral papilla and opening. Place finger tip gently on top of the papilla, taking care to not press too firmly otherwise you will close the urethral opening.
    • Some will opt to use an otoscope or vaginal speculum placed into the vestibule to aid in the visualization of the urethral opening.
    • The urethral opening is on the ventral aspect of the vestibular floor, just caudal to the vestibulo-vaginal stenosis. You will likely be able to palpate the pubis through the ventral aspect of the vestibule- this will be cranial to the urethral opening.
  • Place the catheter into the vestibule, and advance it towards the urethral opening under your fingertip. You will use your finger tip to help direct the catheter ventrally into the urethral opening.
  • If you detect the catheter passing past your finger, the catheter has likely missed the urethral opening and you will need to re-attempt placement.
  • Once catheter has entered the urethral opening, continue advancing the catheter until the bladder is reached.
Cross section of the urogenital tract of the female dog. Note the placement of the urethral opening on the ventral aspect of the vestibule, caudal to the pubis.
Image from: Clinical Techniques in Small Animal Practice
Volume 20, Issue 1, February 2005, Pages 2-10.

(*Note that some clinicians and technicians will opt to surgically scrub their hands and not wear gloves for this procedure, as they find that they can more easily detect the urethral opening without gloves. This is ultimately up to the primary clinician, but note that if you use well-fitted gloves, you should be able to palpate the opening properly).

Video of Canine Female Urinary Catheter Placement:

 

License

VETM 4540: Medical Procedures Copyright © by Shauna L. Blois; Anthony Abrams-Ogg; and Alice Defarges. All Rights Reserved.

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