The solution to some chronic urinary tract infections is not always (or only) antibiotics. When female dogs present excessive or redundant skin folds dorsally and laterally to the vulva, a cascade of events can follow.
Common complaints from the owner include excessive licking of the vulvar area, scooting, malodor, hematuria and sometimes urinary incontinence. How can a simple skin fold cause so much trouble?
The redundant skin fold acts like a dam and enables urine retention. Moisture, body heat, darkness and accumulation of skin debris create a perfect environment for bacteria to proliferate and cause local infection.
Friction between the two skin surfaces causes microtrauma, which adds to self-trauma via licking and scooting. This leads to skin fold dermatitis or pyoderma. In turn, secondary vestibulitis, vaginitis or ascending UTIs have been reported. At worst, urinary incontinence can occur.
The poster child for this condition is an overweight female dog with a hypoplastic or recessed vulva. The mean weight was 71 pounds in one study (1). Another study reports the condition in medium to giant breeds, except for one bichon frise (2). The mean age was approximately 3.5 years in both studies.
The diagnosis is confirmed by careful observation of the redundant skin folds and the dermatitis. A good light source is important since sometimes, you can’t even see the vulva.
Redundant vulvar fold in a 6 yo Border Collie (can you see the vulva?)
Medical management entails using systemic antibiotics and topical treatments, as well as weight loss. The results are “generally palliative and unrewarding.” (1)
The definitive treatment is episioplasty or vulvoplasty, which is the surgical excision of the redundant perivulvar skin folds. This reconstructive procedure provides better ventilation of the perivulvar area.
A purse string suture may be placed around the anus to avoid fecal contamination of the surgical site. Two concentric crescent-shaped incisions are made laterally and dorsally to the vulva. The skin and the subcutaneous tissue are excised. The skin is sutured in a standard fashion, which eliminates the skin fold.
If you choose, you can use an intradermal suture pattern, which avoids the need for suture removal. A simple suture recheck is performed 14-21 days after surgery. Self-trauma is avoided by using an Elizabethan collar. Confinement is recommended for 2-3 weeks. Analgesics and antibiotics are prescribed for 7 days or so.
If the fold is not eliminated appropriately after suturing the skin, then too little skin was removed and a wider excision is performed. If too much skin is excised, tension will ensue. This can cause wound dehiscence. The treatment would be difficult, to say the least, in an area with little loose skin. This complication can be avoided by thoughtful surgical planning, which may include the use of a surgical marker.
After vulvoplasty the vulva is visible.
Two studies reviewed the results of the procedure. In one report of 34 cases, more than 80% of owners were satisfied with the results (2). The other study followed 31 cases: “Owner satisfaction was extremely high” as complete resolution was achieved in 100% of cases with only minor complications (1).
If urinary incontinence persists despite corrective surgery, another etiology should be investigated: pelvic bladder, hormonal deficiency, ectopic ureter, etc.
Bacterial culture most commonly reveals E. coli, but multiple other bacteria can be found.
Mean duration of symptoms was over 1 year in both studies, which confirms that this condition is easy to overlook and probably under-diagnosed. It is important to include it in the differential diagnosis of chronic UTIs.
Interestingly, the only recurrence was in a dog that gained 20 pounds. Weight loss solved the problem in that dog.
Although surgical treatment can be challenging, the prognosis of an episioplasty is excellent.
The two main challenges are:
1. Assessing precisely how much skin to remove (not too much, not too little), and
2. Closing the surgical site in a cosmetic manner.
Recognizing this fairly common problem in our ever-fattening canine population is the first step.
References:
1. BA Lightner et al. “Episioplasty for the treatment of perivulvar dermatitis or recurrent urinary tract infections in dogs with excessive perivulvar skin folds: 31 cases (1983-2000).” JAVMA 2001, Vol. 219, N. 11, p. 1577-1581.
2. AP Hammel and DE Bjorling. “Results of Vulvoplasty for Treatment of Recessed Vulva in Dogs.” JAAHA 2002, Vol. 38, N.1, p. 79-83.
Feel free to call should you have specific questions about these cases or any others in your hospital.
See you in the OR.