In the Literature
Abrams BE, Selmic LE, Howard J, et al. Randomized controlled trial to evaluate a novel two-catheter technique for urethral catheterization in anesthetized healthy female cats and small dogs. Am J Vet Res. 2020;81(5):448-452.
The Research …
Passage of a urethral catheter in female cats and small female dogs can sometimes be challenging due to patient size. This study describes a novel technique in which a large catheter (ie, 10 Fr in most cats, 18 Fr in dogs) is sterilely passed into the vagina of anesthetized female cats and small female dogs (<22 lb [10 kg]) until the tip can no longer be advanced cranially. The open end of the catheter is then reflected dorsally and held in place while a smaller catheter (ie, 5 Fr in cats, 8 Fr in dogs) is inserted beneath the larger catheter and directed along the midline of the vestibule ventrally at an ≈45-degree angle until the catheter advances through the urethral orifice.
The study included 24 cats and 15 dogs anesthetized for ovariohysterectomy. Patients receiving treatment for urinary tract infection, emaciated or obese patients, and patients with abnormal external genitalia were excluded. Catheterizations were performed on a single patient by a board-certified veterinary surgeon with experience in the novel procedure, a board-certified veterinary surgeon with no prior experience using the novel procedure, or a veterinary surgical intern with no prior experience using the novel procedure. Placement of a urethral catheter was also attempted using standard techniques for comparison. The order in which the 2 techniques were performed was randomized. The time required to achieve catheterization was recorded and limited to ≤3 minutes in both techniques. Inability to place the catheter within the timeframe was considered a failure of that technique.
The novel technique was successfully used for urethral catheterization in 19 cats and 12 dogs, with an overall success rate of 31 out of 39 patients. The median time for placement of the urethral catheter was 48 seconds. Urethral catheters were successfully placed in 12 cats and 5 dogs using standard techniques, with an overall success rate of 17 out of 39 patients; catheters were passed in a median time of 41 seconds. The overall success rate for traditional methods was significantly lower than that of the novel catheterization technique. There were no differences in success or time required to place catheters relative to clinician experience.
These results suggest that use of the novel technique for urethral catheter placement in female cats and small female dogs should be considered.
… The Takeaways
Key pearls to put into practice:
Placement of a urethral catheter in female cats and small female dogs can be difficult. Multiple unsuccessful attempts to pass a catheter can be frustrating and can cause irritation or damage to the urethra or vagina.
Results of this study suggest that a novel technique could be successfully performed with minimal prior training. However, it is preferable to practice this technique prior to performing it.
If urethral catheterization is unsuccessful in female cats or small female dogs, further investigation (eg, contrast vaginourethrogram, ultrasonography, endoscopy) should be performed to rule out anatomic barriers to the passage of the urethral catheter.