Treatment for a UTI is based on urine bacterial culture and antimicrobial sensitivity testing. Significant growth from vaginal
bacterial culture samples also prompts appropriate antibiotic therapy. Empirical therapy is not recommended. Mycoplasma species organisms and Escherichia coli may emerge in the vagina during inappropriate antibiotic therapy, strongly arguing against indiscriminate use of antibiotics.20
Anatomical abnormalities. Vaginal anomalies are a common underlying cause of vaginitis, possibly because the anomaly permits urine to pool and irritate
the vaginal mucosa. Urine pooling is best evidenced by positional urinary incontinence (urine leakage when the dog changes
position such as when arising or jumping up), or identified by vaginoscopy. The relevance of vaginal anomalies in the absence
of urine pooling is unknown. Surgical repair of vaginal anomalies depends on the type and extent of the anomaly present.
Urinary incontinence. In most cases, urinary incontinence associated with vaginitis is presumed to be urethral sphincter mechanism incontinence,
formerly called estrogen-responsive urinary incontinence. Treatment with diethylstilbestrol (0.1 to 0.2 mg/kg orally, maximum dose = 1 mg) once a day for five days, tapering to twice
a week, or phenylpropanolamine (1 to 1.5 mg/kg orally) two or three times a day may be of benefit in some bitches.
Perivulvar or perivascular dermatitis. An atrophic, or juvenile, vulva with excessive skin folds has not been reported as a primary cause of vaginitis in the absence
of concurrent perivulvar dermatitis. Overweight dogs with urinary incontinence are prone to perivascular dermatitis because
of excessive perivulvar skin folds and persistent moisture and urine scald. In one study, 18 dogs with vaginitis had complete
resolution of clinical signs after vulvoplasty (episioplasty).21
Systemic disease. Concurrent disease may be identified after performing a complete blood count and serum chemistry profile. Dogs with uncomplicated
vaginitis generally have normal results.2,22 Treat any underlying systemic disease, such as diabetes mellitus or hyperadrenocorticism, first, and if the vaginitis does
not resolve, treat as for idiopathic vaginitis.
Idiopathic vaginitis. Many dogs have idiopathic vaginitis, so several symptomatic therapies have been described. Estrogenic agents such as diethylstilbestrol
may help control subclinical urinary incontinence and may enhance the movement of white blood cells into the vaginal vault
and increase vaginal wall elasticity. Do not use diethylstilbestrol in dogs that have not achieved full adult height because
it may cause premature closure of the physes of long bones. Phenylpropanolamine may also help control subclinical urinary
Histologic examination of vaginal wall biopsies suggests that many dogs with clinical vaginitis have lymphoplasmacytic infiltration
of the wall as a component of inflammation.9 Thus, glucocorticoid therapy may be beneficial in some bitches. To avoid exacerbating a problem likely already distressing
to the owner, I do not use glucocorticoids in dogs with urinary incontinence.
As in juvenile dogs, douching has not been reported to be an effective therapy for vaginitis in adult spayed female dogs.
Finally, I have had some success with diphenhydramine or hydroxyzine in dogs with clinical signs of vaginitis and a history
or clinical findings suggestive of concurrent atopy (Figure 1).
Better identification of conditions known to be primary factors in dogs with vaginitis, such as vaginal anatomical anomalies,
concurrent systemic disease, and, potentially, atopy, will better permit practitioners to understand and treat vaginitis.
Most therapy for vaginitis is symptomatic because most cases are idiopathic. Vaginitis can be frustrating for owners and veterinarians
alike, so it is best to be honest with clients about our limited understanding of its causes and our inability to predict
when and if clinical signs will resolve. I find that most clients adhere to my recommendations if the diagnostic and treatment
plans are thoroughly explained.
Margaret V. Root Kustritz, DVM, PhD, DACT
Department of Veterinary Clinical Sciences
College of Veterinary Medicine
University of Minnesota
St. Paul, MN 55108