Results of Vulvoplasty for Treatment of Recessed Vulva in Dogs
The results of vulvoplasty were evaluated in 34 dogs that underwent surgery at the University of Wisconsin Veterinary Medical Teaching Hospital between 1987 and 1999. Case records were evaluated, and clients were interviewed by telephone. The most common clinical signs of a juvenile or recessed vulva at initial examination were perivulvar dermatitis in 59% (20/34) of dogs and urinary incontinence and chronic urinary tract infection (UTI), each present in 56% (19/34) of dogs. Other common complaints included pollakiuria, irritation, and vaginitis. Most dogs developed clinical signs before 1 year of age. All dogs except one bichon frise were medium to giant breeds, suggesting that vulvar conformation may be related to growth rate or body conformation; prior ovariohysterectomy did not appear to be an influencing factor. Eighty-two percent of owners rated the outcome of the surgery as at least satisfactory. The incidence of urinary incontinence was reduced by vulvoplasty; however, it remained the most common residual sign after surgery, suggesting a multifactorial etiology. The incidences of UTI, vaginitis, and external irritation were greatly reduced after surgery.
Introduction
Older veterinary surgery textbooks indicate that ovariohysterectomy (OHE) performed in dogs prior to the completion of puberty decreases the release of estrogen, preventing normal development of secondary sex characteristics.1 Although never proven, it has been postulated that one result of this process may be a recessed, juvenile vulva.12 In obese, ovariohysterectomized female dogs, a recessed vulva in conjunction with redundant vulvar skin folds may prevent complete elimination of urine and vaginal secretions. Retention of fluid combined with frictional irritation predisposes the area to bacterial growth, infection, and ulceration.3 In addition, urine dribbling has been reported in these dogs, possibly as a result of urovagina due to the conformation of the vulva and overlying skin folds that act as a dam to retain urine within the vagina.4 Affected dogs may exhibit perivulvar dermatitis, pollakiuria, urinary incontinence, licking or other signs of irritation, chronic urinary tract infection (UTI), or vaginitis with or without discharge. In extreme cases, chronic perivulvar dermatitis leading to hyperpigmentation has been associated with neoplasia of the canine vulva.2
Many treatments have been used to palliate conditions that result from abnormal vulvar conformation, including weight reduction, regular cleaning of the affected perivulvar tissue, and various topical or systemic medications to control dermatitis or urinary incontinence. Of the various techniques used, the most successful appears to be removal of redundant tissue overlying the vulva (i.e., vulvar folds), a procedure referred to as episioplasty or vulvoplasty.2 However, little information is available regarding the outcome of vulvoplasty in dogs. This procedure increases exposure of the external genitalia and eliminates redundant skin folds that overly the vulva, which reportedly helps to eliminate primary clinical signs such as dermatitis and urine dribbling, as well as secondary signs such as licking and self-induced trauma.25
The primary purpose of this report was to evaluate the outcome of vulvoplasty by retrospectively reviewing clinical records and contacting clients to determine the resolution or persistence of original complaints subsequent to performance of vulvoplasty in dogs. Secondarily, the authors examined the relevance of possible predisposing factors to juvenile vulva, such as breed and age at which OHE was performed.
Materials and Methods
Case selection criterion was defined as a patient that had undergone vulvoplasty to correct a clinical abnormality. Cases were identified by internal search of the University of Wisconsin Veterinary Medical Teaching Hospital (VMTH) computer records and by manually reviewing surgical logs from 1987 to 1999.
Vulvoplasty was performed in all dogs as described previously.25 Briefly, dogs were placed in ventral recumbency with the hind limbs elevated. Concentric, crescent-shaped incisions were made between the vulva and the anus to remove redundant skin. These incisions extended laterally on either side of the vulva and met at a point ventral to the vulva. If insufficient skin was removed initially to satisfactorily improve the conformation of the vulva, additional skin was removed to achieve the desired effect. Closure of the resultant skin defect eliminated the fold of skin, which previously lay over the dorsal aspect of the vulva, and also removed the depressions lateral to the vulva. Although removal of too much skin may complicate wound closure, failure to remove enough skin may result in persistence of the recessed conformation of the vulva.5 Review of surgical reports indicated that technical performance of surgery was satisfactory in all dogs included in this study except in one dog in which too much skin was removed and dehiscence occurred.
Forty-six vulvoplasty surgeries were performed at the VMTH between July 1987 and August 1999, and data was obtained from these records. Clinical records were evaluated for signalment, clinical signs at the time of initial examination, duration of these signs prior to examination at the VMTH, presence or absence of UTI, prior treatment, and pertinent laboratory data, including urine or vaginal culture.
Clients were contacted by telephone to obtain further information regarding the outcome of treatment. Information was available for 36 dogs. Two surgeries were performed to treat neoplasia, and these dogs were eliminated from the study. The range of time between surgery and contact at this time was 3 to 152 months, and the mean interval was 41 months. All 34 owners of the remaining dogs in the study reported that a veterinarian had examined their pet at least once every year after the surgery. Clients were asked for the primary reason why their dog was evaluated prior to surgery, the duration of clinical signs before surgery, and age at which the animal underwent OHE. They were then asked to subjectively rate the success of the surgery using a scale of “1” to “4,” with “4” indicating resolution to the owner’s satisfaction and “1” signifying complete failure to resolve clinical signs. Owners were subsequently asked to describe any postsurgical complications or continued problems. Finally, owners were asked whether any treatments or surgeries were attempted after the primary procedure and the outcome of these adjunctive therapies.
Results
Age at time of surgery for the 34 dogs ranged from 0.2 to 15.0 years (mean, 3.7 years). Twenty of 34 dogs had shown clinical signs since an early age (<1.0 years). For the remaining 14 dogs, the mean duration of clinical signs prior to surgery, as estimated by owners, was 1.3 years (range, 0.2 to 4 years). Seven (20.5%) dogs in this study were intact when first examined, compared with 28.4% of all female dogs examined at the VMTH. Of the 20 patients whose age at OHE was known, the mean age at time of OHE was 0.8 years. Four dogs underwent OHE ≥1 year of age. It was not possible to compare the age at which OHE was performed in the dogs of this study with the average age at OHE in dogs of the general VMTH population.
Twenty breeds were represented, and all were medium, large, or giant breeds, except one bichon frise. The only breeds represented by more than three dogs were German shepherd dog, golden retriever, and Labrador retriever (five cases each). All three of these breeds are among the four most common breeds examined at the VMTH.
Clinical signs described when the animal was first examined at the VMTH are presented in the Table. Nineteen (56%) dogs had a history of recurrent UTI, and 18 (53%) dogs had a history of vaginitis. Nineteen (56%) dogs had urinary incontinence, and 20 (59%) dogs suffered from perivulvar dermatitis. Abdominal radiographs were made of 18 of the 19 dogs with urinary incontinence. Pelvic bladder, which has been associated with urethral sphincter mechanism incompetence in female dogs,6 was observed in seven (21%) dogs, and six of these dogs exhibited urinary incontinence. The presence of pelvic bladder was confirmed by positive-contrast cystography in all seven dogs. Eleven (32%) dogs had vaginal stricture diagnosed by either digital vaginal examination or positive-contrast vaginourethrography. Only four of these dogs exhibited signs of vaginitis. All dogs with urinary incontinence had failed to respond to medical therapy (i.e., estrogen or phenylpropanolamine) prior to surgery. All dogs with vaginitis or perivulvar dermatitis had received some form of treatment (e.g., systemic antibiotics, vaginal douching, local application of antibacterial ointment, etc.) prior to surgery, but vaginitis or dermatitis persisted in all these dogs.
When asked to rate the success of the surgery on a four-point scale, with “4” being the best result and “1” being a complete failure, 26 (76%) owners rated the outcome of the surgery as fully successful (“4”). Two (6%) owners rated the surgery a “3,” no owners rated the surgery a “2,” and six (18%) owners rated the surgery as having failed (“1”). The rating assigned to the outcome of treatment by the owner was based on the response of the animal to overall treatment, which included medical therapy (i.e., estrogen or phenylpropanolamine) in nine cases.
Persistent urinary incontinence was present after surgery in five of the six dogs for which the owners rated the surgery a failure. Pelvic bladder was identified preoperatively in four of the five dogs with urinary incontinence, which were rated by the owners as treatment failures. Vulvoplasty failed to completely correct incontinence in 13 of the 19 dogs with incontinence postsurgically, but urinary incontinence was controlled medically in nine of these dogs after surgery. In three of the four remaining cases of uncontrolled postsurgical incontinence, the owners did not seek other treatment (e.g., colposuspension surgery or treatment with estrogen or phenylpropanolamine). One dog developed occasional incontinence (rated “3” by the owner) within a year after surgery, with no history of incontinence prior to surgery.
In the 14 dogs in which UTI was confirmed by culture prior to surgery, the six most common bacterial isolates were Escherichia coli (E. coli) (n=6); Proteus spp., Pseudomonas spp., and beta-hemolytic Streptococcus spp. (n=2); and Klebsiella spp. and Enterococcus spp. (n=1 each). By comparison, the six most common isolates from canine urinary tracts at the VMTH from September 1998 to February 2000 were E. coli (53%), Enterococcus spp. (9%), coagulase-positive Staphylococcus spp. (7%), Proteus spp. (6.5%), alpha-hemolytic Streptococcus spp. (4%), and Pseudomonas spp. (4%). The incidence of UTI was reduced from 19 cases presurgically to three cases postsurgically. All 18 dogs with vaginitis showed improvement. One owner reported mild residual signs that were now more amenable to treatment.
There was one report of dehiscence due to removal of too much skin at the surgery site in a bullmastiff. Three additional surgeries were performed to close the wound; however, the final outcome rating in this dog by the owner was a “4.”
Discussion
Seven (21%) of 34 dogs were intact prior to performance of vulvoplasty, and five of 21 dogs in which the age at OHE was known underwent OHE at ≥1 year of age. This data suggests that early OHE is not the sole characteristic that predisposes dogs to an underdeveloped or recessed vulva and associated clinical signs. There is currently no evidence to support the theory that prepubertal OHE predisposes female dogs to urinary incontinence or perivulvar dermatitis.7 Of 21 dogs in which the age at OHE was known, only three underwent OHE prior to 6 months. In a previous study, subjective evaluation indicated little difference in vulvar conformation at 15 months of age between groups of bitches undergoing OHE at 7 weeks versus those undergoing OHE at 7 months.8 The vulvas of females from both groups that had undergone OHE appeared smaller than those of cohort intact females at 15 months of age.8 This suggests that OHE may affect vulvar conformation, but the age at which surgery is performed may be insignificant. Alternatively, the vulva may be larger in animals undergoing OHE at an older age, because they have experienced multiple estrous cycles. Obesity, a condition which may create extra folds around the vulva, is twice as likely to occur in dogs after OHE compared to female dogs which remain intact.9–11 Therefore, OHE may indirectly play a role in the development of recessed vulva by increasing the likelihood of obesity and subsequent development of extra vulvar folds. Unfortunately, because of the subjective nature of evaluation of obesity, insufficient information was available to assess the occurrence and severity of obesity in the cases included in the current report.
All of the cases in this survey involved medium- to giant-breed dogs, with the exception of one bichon frise. The reasons for this are unclear, but it is possible that growth rate or general body conformation may be related to abnormal vulvar development and the onset of clinical signs. The breed distribution of the current study reflects that of the general population of patients at the VMTH.
Urinary incontinence was a common complaint at the time of initial examination at the VMTH. Vulvoplasty appeared to contribute to resolution of urinary incontinence in some dogs. However, there are many factors involved in the development of urinary incontinence,6 and vulvoplasty only addresses one, the external conformation. Potential causes of urinary incontinence should be investigated thoroughly prior to performing any surgery, and persistent urinary incontinence after vulvoplasty is clearly a result of other causes. Prior to surgery, 19 dogs were incontinent. As presented in the Table, six cases resolved with vulvoplasty alone. Residual incontinence was observed after surgery in 13 dogs. No specific therapy for incontinence was instituted immediately after surgery. However, persistent urinary incontinence after surgery was controlled by adjunctive therapy (i.e., estrogen or phenylpropanolamine) in nine of these 13 dogs. It is of interest to note that none of these dogs had responded to medical therapy (in most cases, therapy identical to that instituted after vulvoplasty) prior to surgery.
Pelvic bladder was identified in six dogs with persistent incontinence after vulvoplasty, but medical therapy controlled incontinence in two of these dogs. Caudal displacement of the bladder neck into the pelvic canal is thought to contribute to incontinence from sphincter mechanism incompetence by shortening the urethra as well as preventing exposure of the urethral wall to intra-abdominal pressure.1213 Although caudal displacement of the bladder neck into the pelvic canal can be observed in dogs unaccompanied by urinary incontinence,14 when present in conjunction with urinary incontinence, the intrapelvic location of the bladder neck and proximal urethra is thought to contribute significantly to failure of the urethral sphincter mechanism.12 Correction of the caudal displacement of the bladder neck by colposuspension, a procedure which restores the bladder neck to an intra-abdominal position, has been recommended for treatment of sphincter mechanism incompetence in female dogs with pelvic bladder.12 This was recommended to owners of dogs with this disorder, but further treatment was declined.
Chronic UTIs were eliminated in 84% of dogs with vulvoplasty surgery. One of the dogs in which UTI persisted after surgery had two infections over the course of 4 years. The other two dogs suffered repeated UTI despite appropriate antibiotic therapy, and owners of these dogs also reported signs of persistent incontinence, which suggests that infection may have contributed to apparent incontinence. The distribution of cultured isolates from the urine cultures in this study was similar to that obtained from all cultures performed on urine samples from dogs between September 1998 and February 2000 at the VMTH, consisting mostly of gastrointestinal flora rather than surface bacteria. The authors speculate that vulvoplasty reduces the pathogenic bacterial population in the perivulvar region as well as within the vulva and vagina, decreasing the likelihood for ascending migration of bacteria.
Vulvoplasty appeared to be highly successful in reducing clinical signs associated with chronic vaginitis due to poor vulvar conformation in 100% (18/18) of dogs. None of the dogs in this study appeared to have vaginitis after surgical correction; however, other factors unrelated to the vulvoplasty may have contributed to this success. Vaginal examinations, cultures, or both were not performed in all dogs postsurgically; therefore, the 100% success rate may be incorrect. Also, because the authors relied entirely on owner assessment of outcome, the data may be influenced by misinterpretation of vaginitis as UTI, incontinence, or other clinical conditions. Perhaps the best evaluation of external conformation repair would be resolution or persistence of perivulvar dermatitis. Owners in this study reported an 80% reduction in clinical cases of dermatitis, suggesting a high number of normalized conformations.
Vestibulovaginal stricture was diagnosed in 11 dogs using contrast vaginography. This was not corrected surgically in any dog, and prevalence of vaginal stricture did not correspond with surgical success or failure. Vestibulovaginal stricture is thought to be due to congenital causes and, although many dogs with vestibulovaginal stricture or stenosis are asymptomatic, surgical correction of vestibulovaginal stenosis has been recommended when observed in dogs with chronic UTI or vaginitis or mating difficulties.15 It is assumed that vaginal stricture may promote chronic UTI or vaginitis by causing urine to be retained in the vagina cranial to the urethral orifice. Vulvoplasty may palliate the effects of vestibulovaginal stenosis by decreasing back pressure caused by the folds of skin overlying the vulvar opening, reducing the potential for flow of urine in a cranial direction. Of the 11 dogs diagnosed with stricture preoperatively, all had presurgical urinary incontinence. Incontinence was resolved in 27% (3/11) of these dogs after vulvoplasty, and it is possible that urine retention in the cranial vagina contributed to signs attributed to incontinence. In one previous study, there was no correlation between vaginal stenosis and urinary incontinence in dogs as a result of sphincter mechanism incompetence;12 however, correction of vestibulovaginal stenosis has been recommended in dogs with persistent UTI or vaginitis,15 and this procedure could be considered if vulvoplasty fails to correct these disorders.
The amount of skin removed during surgery varies among dogs, but a primary goal of the surgery is to remove a sufficient amount of skin to eliminate redundant skin dorsal and lateral to the vulva. Wound dehiscence appeared to be an uncommon complication (seen in only one of 36 cases). However, in this dog (a bullmastiff), multiple reconstructive procedures were required to achieve satisfactory healing. Although large quantities of skin are usually available for closure of vulvoplasties, the conformation of the perineal region in this dog limited available skin and resulted in excessive tension on the wound. This case exemplifies the importance of assessing each animal individually when planning the surgery.
Due to the retrospective nature of this study, it was impossible to determine why clinical signs did not resolve in every case. Some signs may be the result of unrecognized anatomical or physiological abnormalities; but in all probability, clinical signs associated with these cases are multifactorial in origin. Vulvoplasty is a useful procedure for treatment of perivulvar dermatitis, vaginitis, and UTI, and may assist in treatment of urinary incontinence in dogs with juvenile or recessed vulvas. The pathogenesis of these disorders is often complex, and while vulvoplasty alone may not entirely resolve the problems, it frequently improves the outcome of treatment.
Contributor Notes
