Vaginal Hyperplasia

Introduction

Vaginal hyperplasia describes the exaggerated response to oestrogens by the vaginal and vestibular mucosa resulting in excessive mucosal folding of the vaginal floor cranial to the external urethral orifice. Redundant tissue protrudes through the vulva as a mass.

It usually occurs during proestrus and oestrus and regresses spontaneously during the luteal phase.

Several grades of hyperplasia have been described:

Type I: slight eversion of the vaginal floor but no protrusion through the vulva

Type II: vaginal tissue prolapses through the vaginal opening: tongue-shaped

Type III: donut-shaped eversion of the entire vaginal wall, including the urethral orifice which can usually be seen ventrally.

Severe hyperplasia can lead to urethral obstruction and prevent urination.

The pathophysiology of the condition is an exaggerated response of the vaginal lining to oestrogens normally present during proestrus and oestrus. Some bitches also have follicular cysts.

The condition is usually seen in younger bitches, typically during their first oestrous period.

Increased incidence has been reported in bulldogs, boxers and other brachycephalic breeds, which might suggest an inherited component.

Clinical Signs

The bitch will have a history of being in proestrus or oestrus. There may be excessive licking of the vulva, or straining to urinate. A mass will usually be visible protruding from the vulva.

Vaginal examination will help determine the extend of the hyperplasia and prolapse, as well as the position of the urethral orifice.

The mass may be dry or necrotic due to it being subject to trauma, inflammation and ulceration.

Treatment

Conservative treatment is sufficient in the majority of cases, as the hyperplastic mucosa regresses at the onset of metoestrus when oestrogen concentrations decrease. The tissue will usually return to normal within a few weeks provided there has been no trauma.

Emollient creams may help keep the tissue moist until it regresses.

Ovariohysterectomy after the season is a permanent cure for the condition.

If the mass has become traumatised or necrotic, it will need to be resected via an episiotomy.

1. Bitch is positioned in sternal recumbency, perineum prepped and purse-string suture placed around the anus.
2. Episiotomy is performed by incising skin dorsally from the commissure of the vulva midline and deepening through subcutaneous tissues to the vestibule.
3. The mass is lifted from the vaginal floor and the redundant vaginal tissue is amputated by making a transverse elliptical incision around the base.
4. The vaginal defect is closed with simple iterrupted absorbable sutures marking sure the external urethral orifice isn't involved.
5. The episiotomy is closed in 2-3 layers, involving the vestibular mucosa, the subcutaneous tissues and the skin.

Post-operatively, the bitch should be confined to a clean area to prevent contamination, and may benefit from the placement of a buster collar.

Affected animals should probably not be bred from, and an ovariohysterectomy should be performed.

Vaginal Hyperplasia Learning Resources
Flashcards Test your knowledge using flashcard type questions	Small Animal Abdominal and Metabolic Disorders Q&A 03

References

Gregory, S. (2010) Surgical considerations of the female genital tract RVC student notes

Mazzaferro, E. (2011) Blackwell's Five-Minute Veterinary Consult Clinical Companion: Small Animal ECC Wiley-Blackwell

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