Disorders of the Vagina and Vulva

17 Disorders of the Vagina and Vulva




FREQUENTLY ASKED QUESTIONS



1) My puppy has a very tucked up vulva. Should I let her go through one heat cycle before spaying to make it look more normal?

Going through heat increases vulvar size only in the short term. If you have no other reason to leave this bitch intact, go ahead and get her spayed.


2) Do dogs get vaginal yeast infections like women do?

There are very few reports of yeast as a cause of vaginitis in dogs. It is not known whether human treatments for vaginal infection work in dogs, but there is little evidence at this time to support their use in dogs, nor are those medications approved for use in dogs.



I. VULVAR DISCHARGE


Discharge exuding from the vulva of bitches may arise from the uterus, cervix, vagina, or urinary tract (Figure 17-1). Localization of the source of the discharge often requires diagnostic testing of the reproductive tract and urinary tract at the same time. Urine is collected from the urinary bladder by cystocentesis, in which a needle is passed directly into the urinary bladder through the body wall. This prevents contamination of the urine with material from the vagina. Other diagnostic tests that allow localization of the source of vulvar discharge include examination of the vagina with a gloved finger or lighted scope, radiographs, ultrasound, submission of samples for culture, and examination of samples from the urinary or reproductive tracts microscopically to assess for the presence of blood, inflammatory cells, or abnormal cells as might be seen in animals with neoplasia. Finally, apparent vulvar discharge may arise from the skin around the vulva or may be expressed anal glands.


image

Figure 17-1 Vulvar discharge algorithm.


Vulvar discharge may be normal or abnormal. Determination of whether or not vulvar discharge is normal and localization of its source require physical examination and appropriate diagnostic testing (Table 17-1).



Table 17-1 Vulvar Discharges of the Bitch

image image


II. VAGINAL ANOMALIES



A. DEVELOPMENT


Anatomic anomalies of the vaginal vault most commonly arise just cranial to the urethral papilla. This is the site of junction of the two different tissues involved in embryologic development of the vagina: the cranial paramesonephric ducts and the caudal urogenital sinus. Two broad types of anomalies are described: septa and strictures.


Vaginal septa are pillars or walls of tissue that form where dissolution of tissue normally would have occurred. A single pillar of tissue may be present just cranial to the urethral papilla (Figure 17-2) or the entire vaginal vault may be split. The split may be symmetrical or asymmetrical.


image

Figure 17-2 Vaginal septum.


Vaginal strictures are 360-degree constrictions. These usually occur just cranial to the urethral papilla but also are described at the level of the vulvar lips and elsewhere in the vagina. There is a normal narrowing cranial to the urethral papilla, the cingulum, which should not be confused with a pathologic stricture (Figure 17-3).


image

Figure 17-3 Vaginogram.



B. SIGNALMENT


These developmental defects are present in dogs from birth. Their true incidence is not known because many dogs are not used for breeding and never undergo a vaginal examination because they carry the anomaly with no associated clinical signs. It is not known whether or not vaginal anomalies are hereditary in dogs; they are considered a hereditary defect in mice.



C. HISTORY AND CLINICAL SIGNS


Many dogs carry vaginal anomalies with no clinical signs. Reported signs in dogs include urinary incontinence, recurrent urinary tract infections, chronic vaginitis, and inability to breed or whelp naturally. Dogs may show physical changes associated with these conditions, such as mucoid discharge and perivulvar irritation in dogs with vaginitis.



D. DIAGNOSIS


Because these abnormalities most commonly develop just cranial to the urethral papilla, most can be identified by examination of the vagina with a gloved finger, even in very large dogs. Hormones will alter the flexibility of the vagina. It is recommended that all bitches be evaluated during proestrus or estrus before a vaginal anomaly is declared to be so extensive as likely to preclude natural service. Investigation of the vagina with a lighted scope (vaginoscopy) may be diagnostic but sometimes the scope will bypass the anomaly and not be visible. Contrast vaginography, in which the vagina of a sedated bitch is distended with a fluid that appears very white on radiographs, is recommended before any surgical repair is considered, to permit evaluation of the entire vaginal vault.



E. TREATMENT


Surgical repair can be effected in most bitches. Because much of the vagina cannot be accessed surgically without breaking the bones of the pelvis, animals with very extensive vaginal anomalies should be spayed and the anomaly left in place without repair whenever possible. Bitches that have difficulty during breeding by natural service may be bred by artificial insemination. The anomaly may or may not cause a problem at whelping; dogs produce a hormone, relaxin, during late pregnancy that often causes such an increase in elasticity of the anomaly that it does not cause dystocia.



F. PROGNOSIS


Prognosis with surgical repair is excellent. Vaginoplasty, in which the size of the vaginal vault is increased by an incision on the floor of the vagina, is preferred to techniques in which a ring of tissue is removed from the vaginal wall because the former is less likely to be associated with constriction attributable to scarring during healing.



III. VAGINAL PROLAPSE



A. DEVELOPMENT


Vaginal prolapse is an overreaction of vaginal tissue to normal hormone production during proestrus and estrus. It is normal for vaginal tissue to become edematous and enlarged during proestrus because of the presence of elevated concentrations of estrogen in blood (see Chapter 9). In bitches that exhibit vaginal prolapse, the concentration of estrogen is not abnormal but the vaginal tissue becomes so enlarged that it falls out of the vaginal vault.



B. SIGNALMENT


This condition is most common in young, large- to giant-breed dogs. Because it is seen so much more commonly in large and giant breeds, a hereditary predisposition is suspected but has not been proven. The condition can first appear in older bitches, but those bitches probably had mild vaginal prolapse when young and did not present with the condition clinically until older.



C. HISTORY AND CLINICAL SIGNS


Three stages of vaginal prolapse are described. Stage 1 is swelling of the perineal area (the area surrounding the anus and vulva). Stage 2 is protrusion of tissue from the floor of the vagina as a “tongue” of tissue (Figure 17-4). Stage 3 is protrusion of the entire circumference of the vagina as a “doughnut” of tissue. The urethral opening always is on the bottom of the prolapsed tissue and rarely is obstructed. Most bitches tolerate the prolapse with no other clinical signs.


image

Figure 17-4 Stage 2 vaginal prolapse.


(Courtesy Dr. Carl Osborne.)

< div class='tao-gold-member'>

Related posts:

  1. Anatomy and Reproductive Physiology
  2. Embryology
  3. Disorders of the Penis and Prepuce
  4. Pharmacology

Stay updated, free articles. Join our Telegram channel
Tags:
Jul 18, 2016 | Posted by in PHARMACOLOGY, TOXICOLOGY & THERAPEUTICS | Comments Off on Disorders of the Vagina and Vulva

Full access? Get Clinical Tree
Get Clinical Tree app for offline access