Introduction

A recessed vulva is a conformational abnormality that is characterized by excessive perivulvar skin folds. This condition increases local skin friction and moisture accumulation, predisposing affected dogs to perivulvar dermatitis, vaginitis, and urinary tract infection.¹ In some cases, perivulvar folds can obstruct the vulvar opening, trapping urine in the vestibule and vagina, leading to ascending urinary tract infection and clinical signs of apparent urinary incontinence.²

Episioplasty is recommended to correct this conformational abnormality when medical management of recurrent dermatitis or urinary tract infections has failed.³ The pathogenesis of perivulvar dermatitis and associated urinary tract infections in affected dogs is likely multifactorial.^1,4 In one study evaluating dogs with lower urinary tract disease (urinary tract infections, urinary incontinence, vaginitis, and perivulvar dermatitis), 8/20 dogs presented for episioplasty had an intrapelvic bladder, and 5/20 were diagnosed with vestibulovaginal stenosis.⁵ However, only 4/8 dogs with an intrapelvic bladder and 1/5 dogs with vestibulovaginal stenosis had subjective improvement of their clinical signs with episioplasty.⁵ This differs from results described by previous studies that showed resolution of chronic urinary tract infection in 84%⁴ and 100%¹ of dogs undergoing episioplasty. The results described in Crawford and Adams’s study suggestthata complete evaluation of theurogenital tract is indicated in dogs presenting for episioplasty to diagnose concurrent abnormalities of the urogenital tract that may predispose affected dogs to recurrent urinary tract infections and limit the effectiveness of episioplasty.⁵ However, a study evaluating the relationship between vestibulovaginal stenosis and the presence of urinary tract infection found no significant difference in the vestibulovaginal ratio in female dogs with or without urinary tract infections.⁶

Vaginocystourethrography and cystoscopy can be used to evaluate the urogenital tract for anatomic abnormalities.^7–9 Vaginocystourethrography is a useful and readily available tool for diagnosing anatomic abnormalities in the lower urinary tract such as ectopic ureters, pelvic bladder, vestibulovaginal stenosis, and diverticuli.^5,7,8 Cystoscopy allows for direct visualization of the urogenital tract lumen, biopsy and culture sampling, and definitive treatment of anatomical abnormalities such as intramural ectopic ureters and vaginal septae at the time of evaluation.¹⁰ The objective of this study was to describe the type and prevalence of urogenital abnormalities visualized by cystoscopy in dogs presenting for episioplasty.

Materials and Methods

Medical records from the University of Pennsylvania School of Veterinary Medicine from 2011 to 2019 were searched for dogs that had an episioplasty performed. Dogs that had prior or concurrent cystoscopy were included in the study. Age, breed, physical examination findings, body condition score (1–9), presenting complaint, duration of clinical signs, previous diagnostics, previous culture results and antibiotic therapy, culture results from time of surgical consultation or procedure, and cystoscopy findings (based on procedure reports) and treatment(s) were recorded.

Cystoscopy was performed with the patients in dorsal recumbency using a Storz rigid 30-degree cystoscope^a and corresponding sheath (1.9 mm scope/9 Fr sheath), 2.7 mm scope/11 Fr or 14 Fr sheath, and 4 mm scope/17 Fr sheath) with saline ingress for distension, based on patient size. Episioplasty was performed as previously described.^1–4

Results

Twenty-nine dogs were included in the study. Twenty-seven dogs were spayed, and 2 dogs had ovariohysterectomy performed at the same time as the episioplasty procedure. Affected breeds included English bulldog (n = 3), golden retriever (n = 2), American Staffordshire terrier (n = 2), basset hound (n = 2), pug (n = 1), German shepherd dog (n = 1), bichon frise (n = 1), Australian cattle dog (n = 1), Spanish water dog (n = 1), Brittany (n = 1), shih tzu (n = 1), Great Pyrenees (n = 1), mastiff (n = 1), Pembroke Welsh corgi (n = 1), French bulldog (n = 1), Newfoundland (n = 1), and Labrador retriever (n = 1); 7 dogs were mixed breeds. Ages ranged from 9moto13 yr (median = 4yr). Dogs’ body condition scores (BCSs) ranged from 4/9 to 8/9 with a median of 5/9. Twelve dogs had a BCS of 5/9, 8 had a BCS of 6/9, 3 had a BCS of 7/9, 3 had a BCS of 4/9, and 1 dog had a BCS of 8/9.

Physical examination findings and historical complaints included recessed vulva (29/29), presumed or documented recurrent urinary tract infection (29/29), perivulvar staining (12/29), urinary incontinence (10/29), perivulvar dermatitis (8/29), and vaginal discharge (1/29). The duration of clinical signs ranged from 2 mo to 11.5 yr (median = 12 mo). None of the dogs had records of a diagnosed endocrinopathy that may have contributed to their clinical signs.

Diagnostic tests performed before cystoscopy evaluation included abdominal ultrasound (n = 14), abdominal radiographs (n = 5), vaginoscopy (n = 1), and computed tomography (n = 1). Three dogs were previously diagnosed with bilateral intramural ectopic ureters via abdominal ultrasound and cystoscopy and were corrected with laser ablation before presentation for episioplasty. Episioplasty was performed 4, 5, and 20 mo after ectopic ureter laser ablation. One dog had a revision laser ablation 10 mo before episioplasty and had a cystoscopy performed again in conjunction with episioplasty. The remaining two dogs did not have cystoscopy repeated in conjunction with the episioplasty procedure.

All 29 dogs had had urine cultures performed before presentation; results were available for 25/29 dogs. One to 4 previous culture results were available for each of these dogs. All 25 dogs had positive cultures. Bacterial isolates included Escherichia coli (n = 13), multidrug resistant Ecoli (n = 6), Enterococcus faecalis (n = 8), Proteus mirabilis (n = 7), Staphylococcus pseudintermedius (n = 3), methicillin-resistant Staphylococcus aureus (n = 2), Klebsiella pneumoniae (n = 1), multidrug resistant Kpneumoniae (n = 1), methicillin-resistant S pseudintermedius (n = 1), Pseudomonas aeruginosa (n = 2), methicillin-resistant Staphylococcus schleiferi (n = 2), Citrobacter freundii (n = 1), and Escherichia fergusonii (n = 1). Six of the 25 dogs had cultures with two isolates, and 19 cultures had a single isolate. Twenty-eight dogs were treated with one (n = 10), two (n = 5), three (n = 8), four (n = 2), five (n = 2), and seven (n = 1) different antibiotics before presentation for documented or presumed urinary tract infection or perivulvar dermatitis. Antibiotic treatment before presentation was unknown in 1 dog. Fourteen of 29 dogs were on antibiotic therapy at presentation for episioplasty.

Eleven dogs (38%) had anatomical abnormalities found on cystoscopic examination. One dog was diagnosed with an os clitoris while under general anesthesia during a digital vaginal examination before a cystoscopy was performed. Eight dogs had a single abnormality (bilateral ectopic ureters [n = 1], urethral papilla mass [n = 1], short urethra [n = 2], urethral stricture [n = 1], persistent paramesonephric septal remnant [PPSR; n = 2],osclitoris[n = 1)). Three dogs had two abnormalities (ectopic ureter and PPSR in all 3 cases), and 1 dog had 3 abnormalities (ectopic ureters, PPSR, and a short urethra). Cystoscopy was performed before presentation for episioplasty in 3 cases previously treated for intramural ureteral ectopia (one of these cases had a cystoscopy repeated in conjunction with episioplasty). The remaining cases had cystoscopy performed in conjunction with episioplasty. Anatomic abnormalities included a PPSR (n = 7; three of which were diagnosed and treated with laser ablation before episioplasty), bilateral intramural ectopic ureters (n = 4; three of which were diagnosed and treated before episioplasty), a short urethra¹¹ (n = 3; one of which was diagnosed before episioplasty and was also confirmed to have a pelvic bladder via contrast fluoroscopy), a unilateral intramural ectopic ureter (n = 1), a mass on the urethral papilla (n = 1), and a urethral stricture (n = 1).

Eight of the 12 dogs with anatomic abnormalities had a reported history of incontinence. All dogs with intramural ureteral ectopia (n = 5) had history of incontinence, 1 of whom was diagnosed with ureteral ectopia alone, 3 of whom were diagnosed with a concurrent PPSR, and 1 of whom was diagnosed with a PPSR and a short urethra. The remaining 3 dogs with anatomic abnormalities and a history of incontinence were diagnosed with a short urethra alone (n = 2) and PPSR alone (n = 1). Four of the 12 dogs with anatomic abnormalities had no history of incontinence and were diagnosed with a urethral papilla mass (n = 1), osclitoris (n = 1), urethral stricture (n = 1), and PPSR (n = 1). Only 2 of the 17 dogs without anatomic abnormalities had a reported history of incontinence.

Ten of the 12 dogs that had anatomical abnormalities that were diagnosed via cystoscopy or vaginal examination (os clitoris) were corrected surgically or with cystoscopic assistance. Both the urethral papilla mass and the os clitoris were surgically resected. The remaining 8 cases had their anatomic abnormalities corrected via cystoscopy. Five dogs with intramural ectopic ureters (4 bilateral, 1 unilateral) had cystoscopic guided laser ablation to reposition the ureteral openings within the bladder trigone. Five dogs with PPSR were treated with laser ablation; two remaining cases with a PPSR had the structure disrupted with the cystoscope alone. The urethral stricture was ballooned under endoscopic and fluoroscopic visualization. The three dogs diagnosed with a short urethra had an episioplasty alone, and the short urethra was not addressed surgically.

Discussion

This study demonstrates that 12 of 29(41%) dogs who presented for episioplasty had concurrent urogenital anatomical abnormalities. Three of these cases had ectopic ureters and PPSR corrected before presentation for episioplasty. One of the 12 dogs was diagnosed with an os clitoris while under general anesthesia during a vaginal examination before cystoscopy was attempted. The remaining 11 dogs with diagnosed anatomical abnormalities in their lower urinary tract were diagnosed via cystoscopy (38%). Ten of the 12 dogs with anatomical abnormalities had corrective procedures performed, 8 of which were performed cystoscopically. The prevalence of concurrent PPSR and ureteral ectopy (4/5; 80%) was similar to that of a previous report (83%).¹² In addition, 8 out of the 10 patients with a history of urinary incontinence had anatomic abnormalities on cystoscopy. Although the clinical implications of the presence of an os clitoris or PPSR are unclear, the findings in this study highlight the effectiveness of cystoscopy as a diagnostic and an interventional tool for assessment and treatment of concurrent urinary tract abnormalities in dogs presented for episioplasty.

All the dogs included in the study had a history of recurrent urinary tract infection. A working group of the International Society for Companion Animal Infectious Diseases adopted the human medical definition of recurrent bacterial cystitis as three or more episodes of clinical bacterial cystitis in a period of 12 mo or two or more episodes in a period of 6 mo.¹³ The International Society for Companion Animal Infectious Diseases antimicrobial use guidelines for urinary tract disease states that repeated treatment with antimicrobial agents in cases of recurrent bacterial cystitis is not likely to provide a long-term cure, and, for this reason, an effort should be made in identifying the underlying cause of the recurrent infections.¹³ In this study, 18/28 dogs were treated with more than one antimicrobial agent, and 13/28 dogs were treated with more than two antimicrobial agents. Eight of 25 dogs were infected with an antibiotic-resistant bacterial strain. Cystoscopic urinary tract abnormalities were identified frequently in one study of female dogs with recurrent urinary tract infections.¹¹ Ninety-one percent of dogs had abnormalities, although these included mucosal edema and prominent lymphoid follicles, which occurred in 27% of cases.¹¹ Sixty-nine percent of these dogs also had a recessed vulva.¹¹ Our study focused on anatomical abnormalities, partially explaining the discrepancy in the results of the two studies. The pathogenesis of urinary tract infections in female dogs is clearly multifactorial, and not all dogs with a recessed vulva develop recurrent urinary tract infections. The prevalence of urogenital anatomic abnormalities in dogs with a recessed vulva that do not have recurrent urinary tract infections may be different from the prevalence reported in our study.

Common predisposing factors for bacterial cystitis include endocrinopathy, kidney disease, obesity, abnormal vulvar conformation, ectopic ureters, mesonephric duct abnormalities, pelvic bladder, bladder tumor, polypoid cystitis, urolithiasis, immunosuppressive therapy, rectal fistula, and urinary incontinence or retention.^13–15 Once the more common and readily available diagnostics are exhausted (urine culture, ultrasound, radiography), more advanced imaging modalities should be considered. These may include contrast imaging or cystoscopy.¹³ Cystoscopy provides direct visualization of the urinary tract and the ability to obtain samples and facilitate the correction of some anatomic abnormalities that may predispose the patient to recurrent urinary tract infections.¹⁰ Failure to properly manage urinary tract infections can lead to repeated and prolonged antimicrobial treatment and the development of antibiotic resistance.¹³ For this reason, it is essential that cases presenting for recurrent bacterial cystitis have additional diagnostics to exclude underlying urinary tract abnormalities that require intervention.

The limitations of this study include its retrospective nature, small sample size, the lack of a control group, and the lack of follow-up. All of the cases in the study were referred to a tertiary academic facility after failing management by their primary veterinarian, and the prevalence reported in this study may not represent the true prevalence of anatomic urogenital abnormalities in the general population of dogs with a recessed vulva. The prevalence of urogenital anatomic abnormalities in female dogs with normal vulvar conformation is unknown, and there are likely many female dogs with a recessed vulva who do not have clinical signs of urinary tract disease. Because of the lack of follow-up information, we were unable to assess the effect of episioplasty and correction of the anatomic urogenital abnormalities on the resolution of urinary tract disease.

Conclusion

This study demonstrates 41% of dogs presenting for episioplasty had concurrent anatomical urogenital abnormalities and suggests that cystoscopy should be considered as a routine part of the evaluation of cases presenting for episioplasty to fully assess for other urogenital abnormalities.