THE OVARIOHYSTERECTOMIZED BITCH.

The diagnosis of any vaginal obstruction (vulvar stricture or vestibulovaginal stenosis) is best made with digital examination of the vaginal vault. Normally, a gloved and lubricated index finger can be passed into the vaginal vault, without pain or difficulty to the bitch, in all but the most miniature breeds (Harvey, 1998). Remember that the veterinarian’s finger is invariably smaller than the erection of the male of that breed. Therefore digital examination of the vaginal vault should be able to be completed without difficulty. If a stricture is suspected, one should proceed slowly and gently in order to avoid causing pain to the bitch. Sedation or anesthesia of the bitch is almost never used, being reserved for those dogs that become vicious when the vulvar area is examined.

USE OF OTOSCOPE OR VAGINAL SPECULUM.

Strictures are typically obvious and immediately evident on digital examination, blocking the normal cranial progress of the digit. Most important, any stricture is likely to be missed if the vaginal examination is performed with an otoscope or vaginal speculum, each of which is narrower and less sensitive than a finger. Such tools can easily bypass any one of these defects, and their use should be limited. It is possible, but rare, for a bitch to be so large that a vaginal stricture cannot be reached digitally or with one of these instruments.

THE ANESTRUAL OR VIRGIN PREPUBERTAL BITCH.

There are two primary exceptions to a simple digital examination diagnosis. One is the virgin intact pubertal bitch that may not be easily palpated and can have remnants of a hymen that might be broken down during breeding or disappear following the relaxation of the vaginal vault. This relaxation can be dramatic when the bitch is under the influence of estrogen. Second, the vagina of an anestrual intact bitch can sometimes be small in diameter, nonpliable, difficult to palpate, or feel as if a stricture is present. In either situation, examination during a subsequent estrus is advised before recommending therapy. The veterinarian can also recommend at least one or two attempts at natural breeding and then repalpate if breeding is not achieved. Some bitches need to be muzzled for breeding or digital examination because of their pain or fear.

VAGINAL CYTOLOGY.

Vaginal cytology from the bitch with a vaginal stricture and an associated low-grade vaginitis usually contains mucoid debris, bacteria (in large or small numbers), and variable to large numbers of neutrophils engulfing bacteria. Large numbers of neutrophils may be seen, and degenerated neutrophils are common. The smears are usually easy to obtain. However, bacteria and neutrophils are seen in normal dogs as well as dogs with vaginitis. In either situation, the findings are nonspecific. If vaginitis is present, the causes are numerous and include common (strictures or foreign bodies, for example) and less common (neoplasia or polyps, for example) problems. Therefore any examination should include a digital evaluation before treatment is suggested or a diagnosis made.

VAGINOSCOPY.

Use of a fiberoptic pediatric proctoscope (see Fig. 25-1) can be an excellent diagnostic aid in visualizing a vaginal defect. Although these instruments are useful diagnostic tools, they are not as sensitive as the digital examination. Use of a vaginogram (radiographic dye study) has been recommended, especially when surgical correction of a vaginal defect is being considered and vaginoscopy is not available (Wykes and Soderberg, 1983; Root et al, 1995; Mathews, 2001; Crawford and Adams, 2002). This procedure has been beneficial diagnostically in some bitches because it has the potential of confirming a diagnosis, defining the location, and identifying a major defect such as a “double vagina” (Fig. 25-3) or a less extensive defect, such as an annular ring (Fig. 25-2).

RADIOLOGY.

If vaginoscopy is not available, a radiographic dye study (vaginogram) is an alternative diagnostic aid. This tool is used in a bitch suspected of having a vaginal stricture not palpable because of its location (this is extremely unusual). We have used the vaginogram in bitches with vulvar hypoplasia because one cannot pass a finger or an instrument through the area of hypoplasia without causing pain or trauma to the bitch. Another indication for a vaginogram is a palpable stricture that prevents evaluation of the cranial vagina (Fig. 25-6). Before surgery or other therapy is considered, evaluation of the entire vagina may be warranted to rule out unsuspected abnormalities (polyp, tumor, foreign body, extensive congenital defect; see Figs. 25-3, 25-4, and 25-6). Furthermore, other congenital anomalies (e.g., urethral ectopia, pelvic bladder) should be ruled out. A urethral pressure profile should be considered (Mathews, 2001).

FIGURE 25-6 Lateral radiograph of the pelvic area from a bitch after the vaginal vault has been filled with radiographic contrast material. The contrast material, which was injected through a Foley catheter, demonstrates the vestibule of the vagina (cranial to the balloon of the catheter), the vaginal vault (curved solid arrow), the stricture located at the juncture of the vestibule with the vault (straight arrow), the urethra (curved open arrow), and the bladder.

The bitch should be anesthetized for the vaginogram. A Foley catheter is placed in the vestibule of the vagina. The balloon is inflated, and a volume of dye is injected through the catheter into the vaginal vault. Radiographs can then be taken to determine whether enough dye has been injected to provide an adequate study. Determining the required volume of dye is a challenge, because it is difficult to predict what amount of dye will pass into the urinary bladder. One report describes a method of “grading” a vestibulovaginal stenosis (vaginal stricture). On review of radiographic cystourethrovaginograms, measurements were made. The dorsoventral height of the vagina was measured at its highest point, and the dorsoventral height of the vestibulovaginal junction was measured at its narrowest point on a lateral radiograph. The ratio of the height at the vestibulovaginal junction to the height of the vagina was calculated. A ratio >0.35 was suggested as normal. Ratios of 0.26 to 0.35 were classified as “mild,” 0.20 to 0.25 as “moderate,” and <0.2 as “severe” vestibulovaginal stenosis (Crawford and Adams, 2002).

THE BREEDING BITCH.

No treatment is recommended if the diagnosis of vaginal obstruction is made in a bitch without clinical signs. A bitch thought to have a vaginal obstruction may breed normally or be artificially inseminated. The artificially inseminated bitch requires close observation to be certain that a vaginal dystocia does not occur during whelping. The fibrous band defects are the easiest to correct because they can be isolated and incised without much difficulty or bleeding. Normal parturition may occur in the bitch with an annular ring if enough relaxation of the vaginal walls allows passage of the newborn through the narrowed area or if the obstruction is broken down during parturition. It is not known whether these defects are inherited, and some have suggested that their surgical correction would be unethical (Harvey, 1998).

Where indicated, correction of congenital vaginal ring obstructions can be accomplished surgically. In most cases, an episiotomy is necessary to provide adequate visualization of the defect. Postsurgical dilation of the vaginal vault may be required to prevent recurrence of vaginal strictures. In addition, correction of vaginal defects does not ensure that the bitch will subsequently allow breeding. (The interested reader should consult surgical references for the necessary procedures: Greene, 1983; Wykes and Soderberg, 1983; Mathews, 2001.) Antiseptic douches can be used as described in the following section.

THE OVARIOHYSTERECTOMIZED BITCH.

Most bitches diagnosed with defects associated with their vaginal lumens have been previously spayed. Before making any treatment recommendation, the owner should be educated with a complete discussion and illustration, such as that in Fig. 25-4. In this manner the owner can understand the problem and can appreciate that no treatment except surgery will permanently resolve the signs. Many owners elect not to surgically treat their pet once they understand that the problem is self-limiting, that it almost never causes systemic illness, and that the signs, although likely to wax and wane throughout the dog’s life, are not life-threatening and may not be as serious or dangerous as the surgery required to correct the defect. Reluctance to perform surgery on these defects stems from the knowledge that the surgical area is not easily reached and that recurrence of a vaginal stricture is always possible. Splitting a pelvis, for example, is considered extremely aggressive, and if the surgeon believes that such an approach would be needed, thorough owner education is advised. Similarly, because the surgery is often in the location of the urethra, iatrogenic incontinence problems would be catastrophic.

If treatment is deemed necessary, a less aggressive attempt at medical treatment is recommended before considering surgery. Treatment is indicated if the bitch is extremely uncomfortable and appears to be in significant pain or if the vaginal discharge is persistent and copious. In these dogs, the approach is to treat with a vaginal douche one to three times daily until the signs abate. We suggest that owners purchase several pediatric enema sets. The enema solution is discarded, but the bottle is a collapsible plastic container with a tapered tip, which is ideal for infusing an antiseptic solution into the vagina. The douche should be a “weak tea–colored” solution of Betadine. The bitch should be treated in an outside location that will not be discolored by the solution that invariably drips out. The bitch can be held up by her rear legs to ensure that the vaginal vault is thoroughly rinsed during or immediately after infusion. Use of antibiotic douche solutions is specifically contraindicated because resistant bacterial strains routinely develop.