Vagina and Vulva

In the bitch, physiologic enlargement of the vulvar labia during proestrus and estrus is a normal estrogenic response. It may be mimicked or exaggerated by masses within the vestibule of the vulva or the vagina that cause the labia to protrude. Such masses include hyperplasia of the vaginal floor, vaginal prolapse, vestibular or vaginal tumors, and clitoral enlargement. Subtle perineal bulges may be detected, but the masses usually become apparent to an animal’s owner when they protrude through the vulva, cause irritation and licking, or interfere with mating. They may cause dysuria. Prolonged estrogenic stimulation from follicular cysts or granulosa cell tumors can cause persistent hyperplasia of the labial and vaginal mucosa, making the labia larger, firm, pigmented, and hairless.

Inspection, digital vaginal or rectal palpation, and vaginoscopy provide preliminary identification of most vaginal lesions. In at least one instance, an intraluminal vaginal tumor was diagnosed by pneumovaginography. Surgical treatment of these lesions is facilitated by episiotomy. Excised neoplasms should be identified histologically.

Hyperplasia of the Vaginal Floor

During proestrus and estrus, the vestibular and vaginal mucosae normally become swollen, thickened, and turgid. Exaggeration of this estrogenic response occasionally leads to the development of a transverse mucosal fold on the floor of the vagina just cranial to the external urethral orifice. Although “hyperplasia” is the accepted term for this condition, histologically the swelling is mostly edema with some fibroplasia. If the redundant fold becomes large enough, it protrudes between the labia of the vulva as a red, fleshy mass (Figure 34-1A). The disorder occurs most often during a bitch’s first, second, or third estrus. Spontaneous regression occurs during metestrus, but recurrence is common at the next estrus. The condition has been reported in more than 20 breeds of dogs, with frequent mention of brachycephalic breeds, such as boxers and English bulldogs.

Because the protrusion is vulnerable to trauma, inflammation, and ulceration, tends to recur, and is aesthetically objectionable, amputation is frequently the treatment of choice. Recurrence after surgical excision is uncommon, and natural mating is possible at subsequent estrous periods. With or without surgical excision, ovariectomy provides permanent relief.

Alternatively, one can manage the condition conservatively until it regresses spontaneously by lubricating the mass with an antibiotic ointment and applying an Elizabethan collar to prevent self-abuse. If breeding during the same estrus is important, artificial insemination can be performed. Simultaneous excision of the mass and artificial insemination are technically possible but seldom indicated.

A third option is to try to shorten the duration of estrogenic stimulation of the vaginal tissue by inducing ovulation at the onset of clinical signs. A single dose of gonadotropin-releasing hormone or human chorionic gonadotropin has been used for this purpose. Regression of the prolapse occurs about 1 week after induction of ovulation.

Surgical Treatment

The animal is positioned in ventral recumbency with the hindquarters elevated, and the perineum is prepared aseptically. The vestibule and vagina are cleansed with a mild antiseptic solution (1:10 povidone-iodine [Betadine] or 1:5000 benzalkonium chloride [Zephiran chloride] solution). A median episiotomy incision is begun with a scalpel or an electrosurgery unit and is completed with scissors. Doyen intestinal forceps can be positioned on each side of the incision to serve as a guide and to reduce bleeding. Hemorrhage is controlled with hemostatic forceps, ligation, or electrocoagulation. Retracting the margins of the episiotomy incision exposes the vaginal lumen. The mass must be elevated for catheterization of the urethra, to identify and protect that structure (Figure 34-1B and C). The superfluous tissue is amputated by making connecting, curved, transverse incisions through its base. One incision is made on the dorsal surface of the mass (the cranial aspect of its base), and the other is made on its ventral surface (the caudal surface of the base of the mass). The incisions should be no deeper than necessary to excise the mass. The mucosal opening is closed with absorbable suture material in a transverse, simple continuous pattern (Figure 34-1D). The catheter is removed, and the episiotomy incision is closed (Figure 34-1E). The mucosa is apposed with simple interrupted absorbable sutures. In obese or heavily muscled animals, the musculature should be sutured separately with absorbable sutures. The skin incision is closed with simple interrupted nonabsorbable sutures. If bleeding persists, a vaginal tampon may be left in place for 12 hours.
 

Vaginal Prolapse

Cylindric prolapse of the vaginal wall is much rarer than hyperplasia of the vaginal floor. In this condition, which also occurs during estrus, a donut-shaped eversion of the entire vaginal circumference protrudes from the vulva (Figure 34-2). Vaginal prolapse has been reported after forcible separation of the male and female during the genital tie. As in hyperplasia of the vaginal floor, the external urethral orifice is ventral to the entire mass, but access to the vaginal canal is through the center of the protrusion, rather than dorsal to it.
 

Complete vaginal prolapse also occurs during parturition or advanced pregnancy, as a prelude to prolapse of the cervix, uterine body, and one or both uterine horns. It results from excessive straining while the supportive tissues are relaxed. The everted organs are usually discolored from venous congestion, soiled, and traumatized.

Some authors prefer to classify hyperplasia of the vaginal floor as a type of vaginal prolapse. According to that interpretation, hyperplasia of the vaginal floor that does not protrude through the vulva is called type I prolapse, and hyperplasia that protrudes completely is called type II. A true cylindric prolapse is called type III.

A recent “type III” vaginal prolapse can be reduced, but recurrence is likely. Recurrence, hemorrhage, infection, and necrosis make amputation necessary. Shock and dehydration are common complications that must be treated appropriately.

Surgical Treatment

With the animal under general anesthesia, the protruding structures are washed gently with warm saline solution or a mild detergent. Additional trauma is avoided. The mass is compressed manually to reduce edema before reduction is attempted. Sprinkling the mucosal surface with table sugar may further reduce the swelling, and episiotomy makes reduction easier. Once accomplished, reduction is maintained by placing heavy nonabsorbable sutures across the vulvar labia.

Reduction of a vaginal prolapse can be facilitated by traction on the uterus through a ventral abdominal incision. When this technique is used, suturing the uterine body or horns to the abdominal wall (hysteropexy) provides protection against recurrence.

If reduction is impossible or inadvisable, the protruding tissue must be amputated. Paying careful attention to the distorted anatomy minimizes errors. With a catheter in place to identify and protect the urethra, a circumferential incision is made in stages through the vaginal wall. The outer, everted mucosa is incised first. The incision is deepened to penetrate all layers of prolapsed vaginal tissue until the inner, noneverted mucosa is reached. Hemostasis is maintained by ligation or electrocoagulation, and the proximal mucosal margins are united with horizontal mattress sutures. The incision is extended for another short distance, the exposed segment is sutured, and the process is repeated until the amputation is complete.

Tumors of the Vulva and Vagina

Vulvar and vaginal neoplasms, which usually occur in older bitches, account for no more than 3% of all canine tumors; 70 to 80% of them are benign. The most common tumors of the vulva and vagina are leiomyoma, fibroma, and lipoma. Leiomyosarcoma is the most common malignant vaginal tumor. Mast cell tumors, sebaceous adenomas, and epidermoid carcinomas have been reported.

Leiomyomas and fibromas are often grossly indistinguishable. They form smooth, firm, spheric masses that are often pedunculated and protrude into the vestibular or vaginal lumen. They may protrude from the vulva and resemble an early hyperplasia of the vaginal floor. Lipomas occur as a gradually enlarging mass under the intact mucosa; they may protrude into the lumen, or they may become apparent under the perineal skin adjacent to the vulva. Surgical excision of benign vulvar and vaginal tumors combined with ovariohysterectomy is effective in preventing recurrence, but malignant tumors have been reported in spayed females.

The transmissible venereal tumor is an allogeneic cellular transplant that is transmitted by implantation of exfoliated cells into traumatized vaginal or penile epithelium. The condition is most prevalent and perhaps most severe when dogs are crowded and stressed. In females, the transmissible venereal tumor appears in the vagina as single or multiple projecting masses with roughened or reddened, ulcerated surfaces. Metastasis is rare. Spontaneous regression occurs after 2 to 6 months in about 60% of experimentally transplanted tumors, but reports of spontaneous regression in naturally occurring cases are inconsistent. Surgical excision is an appropriate initial treatment. If surgery is impossible or if recurrence or metastasis is noted, radiation therapy and chemotherapy are effective. Immunotherapy may be as effective as chemotherapy, but additional clinical trials are needed.

Surgical Treatment

Episiotomy is performed for better exposure. Pedunculated intraluminal tumors can be amputated, but encapsulated extraluminal tumors are removed by submucosal resection (Figure 34-3). An incision is made through the mucosa, and the tumor is bluntly peeled away. The mucosal incision is closed with absorbable sutures. Submucosal resection is especially useful for large or multiple tumors.
 

Clitoral Enlargement

Enlargement of the clitoris, sometimes with an os clitoridis, is an androgenic response. The condition has been caused by administration of exogenous androgens or anabolic steroids, and it has been reported in bitches with hyperadrenocorticism. Clitoral enlargement has occurred in puppies whose dams were treated with androgens during pregnancy. Friction between the protruding clitoris and the vulva may cause inflammation. Treatment includes topical antibiotic ointments, removal of the androgen source, or excision of the enlarged clitoris. If an os clitoridis is not present, the clitoris regresses to normal size when exogenous androgen is withdrawn.

Suggested Readings

Adams WM, Biery DN, Millar HC. Pneumovaginography in the dog: a case report. J Am Vet Radiol Soc 1978; 19:80.

Alexander JE, Lennox WJ. Vaginal prolapse in a bitch. Can Vet J 1961;2:428.

Brodey RS, Roszel JF. Neoplasms of the canine uterus, vagina, and vulva: a clinicopathologic survey of 90 cases. J Am Vet Med Assoc 1967;151:1294.

Johnston SD. Vaginal prolapse. In: Kirk RW, ed. Current veterinary therapy X. Small animal practice. Philadelphia: WB Saunders, 1989:1302.

Krongthong M, Johnston SD. Clinical approach to vaginal/vestibular masses in the bitch. Vet Clin North Am Small Anim Pract 1991;21:509.

Madewell BR, Theilen GH. Tumors of the urinary tract. In: Theilen GH, Madewell BR, eds. Veterinary cancer medicine. 2nd ed. Philadelphia: Lea & Febiger, 1987:591.

Purswell BJ. Vaginal disorders. In: Ettinger SJ, Feldman EC, eds. Textbook of veterinary internal medicine. 4th ed. Philadelphia: WB Saunders, 1995:1642.

Richardson RC. Canine transmissible venereal tumors. Compend Contin Educ Pract Vet 1981;3:951.

Schutte AP. Vaginal prolapse in the bitch. J S Afr Vet Med Assoc 1967;38:197.

Soderberg SF. Vaginal disorders. Vet Clin North Am Small Anim Pract 1986;16:543.
 

Introduction

Episioplasty is a procedure performed most often to treat recessed or juvenile vulva in female dogs. This conformation results in deep perivulvar folds of tissue causing the vulva to be partially or totally hidden from view by overlapping perineal skin dorsal and lateral to the vulva. Older veterinary surgery texts indicate that ovariohysterectomy performed in dogs prior to the completion of puberty prevents normal development of secondary sex characteristics.¹ Although this association has never been proven, it has been postulated that this may result in recessed or juvenile vulva.^1,2 Particularly in obese female dogs, a recessed vulva in conjunction with redundant vulvar skin folds may prevent complete elimination of urine and vaginal secretions. However, this condition may be associated with clinical signs in young, relatively thin female dogs. Recessed or juvenile vulvar conformation can also be observed in female dogs in the absence of any associated clinical signs.

Retention of fluid within the vulva and perivulvar folds 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

Recessed vulva is often accompanied by vaginal stricture located cranial to the urethral orifice. Vaginal stricture is usually diagnosed by positive contrast radiography (vaginourethrography) or by digital palpation. Although it has been suggested that vaginal stricture may contribute to persistent vaginitis or chronic urinary tract infection,⁵ vaginal stricture is commonly observed in asymptomatic female dogs. It is my opinion that episioplasty should be performed prior to revision of vaginal stricture.

Many treatments have been used to palliate conditions that result from abnormal vulvar conformation, including weight reduction, regular cleaning of the affected perivulvar tissue, repeated vaginal flushes with antiseptics, 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 This procedure increases exposure of the external genitalia and eliminates redundant skin folds that overly the vulva, which appears to eliminate primary clinical signs such as dermatitis and urine dribbling, as well as secondary signs such as licking and self-induced trauma.²

Surgical Technique

The surgical procedure is relatively simple. The dog is placed in ventral recumbency with the hindquarters elevated. The skin dorsal and lateral to the vulva is compressed with the fingers to estimate the amount to be removed (Figure 34-4). Concentric crescent-shaped incisions are made between the vulva and the anus to remove redundant skin (Figure 34-5). These incisions extend laterally on either side of the vulva and meet at points lateral and ventral to the vulva. If insufficient skin is removed initially to satisfactorily improve the conformation of the vulva, additional skin is removed to achieve the desired effect. The crescent-shaped skin and associated subcutaneous fat are removed (Figure 34-6), taking care to avoid the dorsal wall of the vagina. The resultant wound is closed in 2 layers. Subcutaneous tissues are closed with synthetic absorbable suture (3-0 or 4-0) in an interrupted pattern, and the skin is closed with monofilament non-absorbable suture (3-0 or 4-0) in an interrupted pattern (Figure 34-7). Closure of the resultant skin defect eliminates the fold of skin that previously lay over the dorsal aspect of the vulva and also removes 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. Closure of the defect is rarely a problem due to the large amount of redundant skin available in the area of the perineum and caudal aspects of the thighs. However, in heavily-muscled dogs, or dogs with a great deal of tension within the perineal skin, care should be taken to avoid removing too much skin.
 

Postoperative Care and Outcome

Wound infection rarely occurs. An Elizabethan collar should be used to prevent self-mutilation, if necessary.

In one study of the results of episioplasty in 34 dogs, the most common clinical signs at initial examination were perivulvar dermatitis 20/34 dogs (59%), and urinary incontinence and chronic urinary tract infection, each present in 19/34 dogs (56%).⁶ 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. 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 urinary tract infection, vaginitis, and external irritation were greatly reduced after surgery. Wound dehiscence occurred in a Bull Mastiff, and multiple additional surgeries were performed to correct the resultant defect. This complication appeared to be due to removal of too much skin combined with a lack of mobility of skin in adjacent areas.

In another study of the outcome of episioplasty in 31 dogs, the primary complaint in 15 dogs was perivulvar dermatitis and repeated urinary tract infection in 16 dogs.⁷ The mean weight of dogs with perivulvar dermatitis or chronic urinary tract infection was 26.7 ± 1.89 kg and 32.43 ± 4.02 kg, respectively, again suggesting that this condition predominantly affects medium and larger size dogs. Performance of episioplasty resulted in complete resolution of perivulvar dermatitis in 15/16 dogs, although 1 dog suffered recurrence of perivulvar dermatitis 2 years after surgery in association with a 9 kg weight gain. Episioplasty was followed by resolution of urinary tract infection in all 16 dogs in this study. Postoperative complications were limited to transient local swelling immediately after surgery.

Dogs with recessed or juvenile vulvas that are examined because of vaginitis, perivulvar dermatitis, or chronic urinary tract infection should be examined carefully for other abnormalities that may be contributing to these clinical problems. However, it is often difficult to control these disorders in the presence of conformational abnormalities of the vulva. Owners should be warned that failure to prevent weight gain may compromise the outcome of the surgery.

References

1. Archibald J. Canine Surgery, 2nd ed. Santa Barbara: American Veterinary Publications. 1974; p 757.
2. Dorn AS. Biopsy in cases of canine vulvar-fold dermatitis and perivulvar pigmentation. Vet Med Small Anim Clin 1978;73:1147.
3. Bellah JR. Intertriginous dermatitis. In Bojrab MJ, ed. Disease Mechanisms in Small Animal Surgery, 2nd ed. Philadelphia: Lea and Febiger. 1993; p 168.
4. Appeldoorn A, Lemmens P, Schrauwen E. Urinary incontinence due to urovagina. Vet Rec 1990;126:121.
5. Crawford JT, Adams WM. Influence of vestibulovaginla stenosis, pelvic bladder, and recessed vulva on response to treatment for clinical signs of lower urinary tract disease in dogs: 38 cases (1990-1999). J Am Vet Med Assoc 2002;221:995.
6. Hammel SP, Bjorling DE. Results of vulvoplasty for treatment of recessed vulva in dogs. J Am Anim Hosp Assoc 2002;38:79.
7. Lightner BA, McLoughlin MA, ChewDJ, et al. Episoplasty for the treatment of perivulvar dermatitis or recurrent urinary tract infections in dogs with excessive perivulvar skin folds: 31 cases (1983-2000). J Am Vet Med Assoc 2001;219:1577.
    

Introduction

Episiotomy is a surgical procedure that temporarily enlarges the vulvar cleft. This procedure provides exposure of the caudal female urogenital tract which cannot be reached with a conventional laparotomy or ventral pubic osteotomy. Indications for an episiotomy in the dog include vaginal and vestibular masses, vaginal prolapse, vaginal and vestibular trauma, congenital vaginal strictures, and dystocia from an inadequate vulvar cleft.

Preoperative Care

Depending on the stability of the patient and the underlying clinical disorder, episiotomies may be performed under local, epidural and general anesthesia. The patient is placed on a padded perineal stand in a manner to prevent neuropraxia, compromised circulation or exacerbate chronic osteoarthritis of the rear limbs. The rectum and anal sacs are emptied, and several gauze sponges are placed into the rectum. A purse string suture is placed in the anus to minimize contamination during surgery.

The hair from the perineal region is clipped and the vestibule and vagina are liberally flushed with a dilute antiseptic solution. Surgical scrub is avoided during lavage of the vestibule and vagina. The perineum is surgically prepared in a routine manner. A Foley catheter is aseptically placed through the urethral papilla into the urinary bladder to allow for exact identification and protection of the lower urinary tract throughout the procedure. Surgical draping includes the vulvar cleft and the perineal skin dorsal to the vulvar cleft with exclusion of the anus.

Surgical Technique

A digital examination precedes the surgical incision. During digital examination, the caudodorsal aspect of the horizontal vaginal canal is identified. To avoid incising the external anal sphincter, the episiotomy incision should not extend any further dorsally than the caudodorsal aspect of the horizontal vaginal canal.

A median skin incision is made from the level of the caudodorsal aspect of the horizontal vaginal canal, extending to the dorsal commissure of the vulvar cleft (Figure 34-8). A pair of thumb forceps or the handle of a scalpel blade can be inserted into the vaginal canal to aid in the stabilization of the incision site. The remaining layers of the episiotomy incision, including the thin musculature, subcutaneous tissue and mucosal layers are cut with Mayo scissors (Figure 34-9). Hemorrhage may be brisk. The use of hemostats, ligatures and the judicious use of electrocautery will control hemorrhage and improve visualization of the surgical field. Alternatively, atraumatic intestinal forceps can be temporarily applied to the edges of the incision to achieve hemostasis.

The definitive surgical procedure that necessitated the episiotomy may be performed at this time. Self retaining retractors can be used to increase exposure at the surgical site. It is imperative that the position of the urethral papilla and the urethra should be visualized and protected at all times (Figure 34-10).

Closure of the episiotomy is completed in three to four layers, depending on the size of the dog. The mucosa is apposed using a simple interrupted suture pattern with 3-0 synthetic, monofilament, absorbable suture material (Figure 34-11A). If the vulvar cleft was congenitally shortened, the vestibular mucosa is directly sutured to the skin until the desired length is attained. The muscular and subcutaneous tissues are closed in one layer using a simple interrupted suture pattern of 3-0 or 4-0 synthetic, monofilament, absorbable suture material. In larger dogs, the muscular and subcutaneous tissues can be closed in separate layers. The skin is apposed with simple interrupted or cruciate mattress sutures of 3-0 synthetic, monofilament, nonabsorable material (Figure 34-11B). The purse string suture and gauze sponges are removed from the anus and rectum, respectively. The urinary catheter may be removed or left in place during the immediate postoperative period.
 

Postoperative Care

An Elizabethan collar is recommended to prevent self mutilation of the surgical site. Analgesia is a requirement. Full opioid agonists, such as oxymorphone or hydromorphone, should be administered for the first 24 hours. If medically appropriate, additional analgesia could be obtained using a non-steroidal anti-inflammatory agent. Cold compresses should be applied for the first 48 hours. Skin sutures should be removed in 10 to 14 days.

Complications

Postoperative complications associated with the performance of episiotomy are rare and are often associated with poor surgical technique or inappropriate postoperative care. Poor surgical technique during closure of the incision, including inaccurate suture placement, tight sutures or the use of through and through sutures, may result in unnecessary pain, self mutilation of the surgical site and inflammation. Urinary obstruction may occur if the urethral papilla and urethra were not identified during the initial incision, the definitive surgical procedure or during the closure of the episiotomy. Vestibular reconstruction for enlargement of the vulvar cleft may predispose to urinary tract infections by way of environmental exposure to gastrointestinal contents.

Suggested Readings

Hardie EM. Selected surgeries of the male and female reproductive tracts. Vet. Clinics of N. America, Small An. Practice. 1984; 14: 109-122.

Mathews KG. Surgery of the canine vagina and vulva. Vet. Clinics of N. America, Small An. Practice. 2001; 13: 271-290.