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Basics ⬇

Basics

Definition

Any substance emanating through the vulvar labia

Pathophysiology

  • Dependent on underlying cause of vaginal discharge.
  • Discharge may originate from uterus, vagina, vestibule, clitoris, clitoral sinus, perivulvar dermis, or urinary tract.

Systems Affected

  • Reproductive
  • Renal
  • Skin
  • Urinary

Incidence/Prevalence

  • Unknown as there are many causes.
  • Considered a common reason for seeking veterinary care.

Signalment

  • Healthy bitch <6–12 months of age (prepubertal)-juvenile (puppy) vaginitis and congenital anomalies more common.
  • Non-pregnant bitch that has undergone at least one estrous cycle-normal estrus, persistent estrus (cystic ovarian disease or granulosa cell tumor); pyometra; neoplasia.
  • Bitch bred in the last 30–70 days-normal parturition (50–70 days) or abortion. (<50 days).
  • Bitch that has recently whelped-normal lochia or postpartum metritis more common; subinvolution of placental sites.
  • Ovariectomized bitch-vaginal stricture or estrogen-responsive urinaryincontinence more common; neoplasia.

Signs

Historical Findings

  • Discharge from the vulva.
  • Licking, scooting, and spotting.
  • Attracting male dogs.
  • Parturition-with postpartum discharge.
  • Recent estrus-with pyometra.
  • Hemorrhagic discharge >8 weeks postpartum-subinvolution of placental sites.
  • Vomiting, anorexia-may be seen with metritis and pyometra.

Physical Examination Findings

  • Vaginal discharge that may be serosanguinous, purulent, lochial, hemorrhagic, mucoid, or urinous.

Causes

Normal Physiologic Conditions

  • Proestrus
  • Estrus
  • Diestrus
  • Late pregnancy
  • Parturition
  • Normal lochia

Pathologic Conditions

  • Cystic ovarian disease (persistent estrus).
  • Brucella canis.
  • Metritis.
  • Pyometra.
  • Retained placenta or fetuses.
  • Subinvolution of placental sites (hemorrhagic discharge postpartum 8 weeks).
  • Neoplasia-uterus, vagina, urinary tract (including transmissible venereal tumor), ovary (granulosa cell tumor/persistent estrus).
  • Vaginitis.
  • Estrogen-responsive urinary incontinence.
  • Coagulopathy.
  • Congenital defects of the distal genital tract-intersex conditions, imperfect embryologic fusion of the Müllerian ducts (vagina), joining of the genital folds (vestibule) and genital swellings (vulvar lips), ectopic ureters.

Risk Factors

  • Prophylactic antibiotics-may alter normal vaginal flora and predispose to secondary infection.
  • Exogenous estrogen-predispose to pyometra in the intact bitch.
  • Exogenous androgens-may cause clitoral hypertrophy.
  • Exogenous or endogenous progesterone-predispose to pyometra or stump pyometra.
  • Obesity-excess skin folds around vulva.

Diagnosis ⬆ ⬇

Diagnosis

Differential Diagnosis

  • Healthy intact bitch <6–12 months of age-juvenile vaginitis (prepubertal), normal estrous cycle, urogenital trauma or neoplasia, foreign body, coagulopathy, ectopic ureter(s), congenital abnormalities of the perineum or distal genital tract, intersex conditions, urinary tract disease.
  • Non-pregnant bitch that has undergone at least one estrous cycle-normal estrus, pyometra, split heat, foreign body, urogenital trauma, neoplasia, coagulopathy, cystic ovarian disease (follicular cysts).
  • Bitch bred in the last 30–70 days-abortion, pyometra, normal parturition (>57 days from breeding), fetal/embryonic death, split heat, Brucella canis infection.
  • Bitch that has recently whelped-lochia (normal up to 6–8 weeks postpartum), subinvolution of placental sites (hemorrhagic discharge 8 weeks postpartum), postpartum metritis, vaginal trauma, retained placenta or fetus.
  • Ovariectomized bitch-vaginal stricture, foreign body, neoplasia, polyps, stump pyometra due to exogenous or endogenous progesterone, exogenous estrogens(exposure to owner's hormone replacement therapy), perivulvar dermatitis, ovarian remnant syndrome, estrogen-responsive urinary incontinence.

CBC/Biochemistry/Urinalysis

  • Regenerative anemia-may be normal in pregnancy or during estrus.
  • Leukocytosis with a left shift-pyometra or postpartum metritis.
  • Elevated BUN and creatinine-pyometra.
  • Isosthenuria-with polyuria and polydipsia associated with pyometra.
  • Urinalysis-may indicate urinary tract infection.

Other Laboratory Tests

  • Progesterone-determine if bitch is in luteal phase, which increases likelihood of pyometra. Progesterone, 17-hydroxyprogesterone may be secreted in animals with adrenal cortex disease (ACTH stim test; Clinical Endocrinology Service, University of Tennessee; (865) 974-5638).
  • Brucella canis serology-screen with rapid slide agglutination test (D-Tec® CB, Zoetis; (888)963-8471); agar gel immunodiffusion test confirmatory (Cornell University Diagnostic Laboratory, (607)253-3900); bacterial culture of whole blood or lymph node aspirate.

Imaging

Radiography

  • Detect enlarged uterus or ovary, pregnancy.
  • Evidence of fetal death-presence of gas around fetus or misalignment and/or collapse of fetal skeleton.

Ultrasonography

  • Determine contents of uterus, free fluid in the uterus is characteristic of pyometra, hydrometra, and mucometra
  • Pregnancy diagnosis and embryonic/fetal wellbeing: heartbeat may be seen as early as the 20th day of diestrus, heart rate <180 bpm indicates fetal stress.
  • Masses-neoplasia, granulomas, cystic ovarian disease or granulosa cell tumor, or foreign body; saline distention of the vagina may help visualization.

Contrast Radiography-Vaginogram/Urethragram/Cystogram/IVP

  • Identify abnormal conformation or structure (i.e., neoplasia or foreign body) within the vagina.
  • Rule-out vestibulovaginal strictures, rectovaginal and urethrovaginal fistulas.
  • Rule-out differentials and help localize the problem.
  • Pronounced folds (rugae) of vagina during estrus will cause filling defects (normal).

Diagnostic Procedures

Vaginal Cytology

  • Determine nature of discharge-inflammatory, hemorrhagic.
  • Evaluate epithelial cells for cornification-cornification present under the influence of estrogen.
  • Always performed in order to interpret vaginal cultures.

Vaginal Culture and Sensitivity

  • Performed prior to other diagnostic procedures.
  • Use guarded swab to sample cranial vagina.
  • Most common organisms in the microbiome (commensals and potential pathogens) are E. coli, Streptococcus spp., Pasteurella spp., and Staphylococcus spp.
  • Other organisms which can be commensals include Mycoplasma spp., Enterobacter spp., Pseudomonas spp., Klebsiella spp.
  • Reminder: the vagina is not a sterile environment and culture of normal bitches results in growth of normal vaginal flora; use of vaginal cytology and other diagnostic tools is essential for interpretation of culture results.
  • Normal microbiome consists of numerous opportunistic pathogens, e.g., E. coli and Mycoplasma spp.

Vaginoscopy

  • Rigid cystourethroscope or ureteroscope; pediatric gastroscope or proctoscope; or flexible endoscope used to visualize vagina.
  • Identify source of vaginal discharge-uterine, vaginal, vestibular, or urethral.
  • Visualize anomalies, persistent hymen, neoplasia, foreign body, trauma, abscess, and evaluate the vaginal and vestibular mucosa.
  • Use of specialized scope to flush uterus if indicated.
  • Removal of foreign body or biopsy of vaginal mass.

Other

  • Digital examination of vestibule, vaginovestibular junction, and distal vagina.
  • Biopsy and histopathology of mass lesions.
  • Cystocentesis-urine culture and sensitivity.
  • Clotting profile.

Treatment ⬆ ⬇

Treatment

Surgical Considerations

  • Pyometra may be medically or surgically (OHE) managed.
  • Ovariectomy or OHE is treatment of choice for neoplastic conditions.
  • Cystic ovarian disease can be medically managed or ovariectomy/OHE performed.
  • Removal of foreign body or surgical excision of mass(es).
  • Surgical excision or radiation therapy are options for TVT.

Medications ⬆ ⬇

Medications

Drug(s) Of Choice

  • Prostaglandin F2 (PGF2) for uterine evacuation (myometrial contractions) and luteolysis-dinoprost (Lutalyse®) 50–100 µg/kg SC q8–24h daily till progesterone level <2.0 ng/mL and uterus is cleared of fluid; cloprostenol (Estrumate®) 1–5 µg/kg SC q24h.
  • Antibiotic-choice based on guarded cranial vaginal culture and sensitivity.
  • Dopamine agonist-may be used in addition to PGF2 for luteolysis via suppression of the luteotropic hormone prolactin-bromocriptine (10 µg/kg PO) or cabergoline (5 µg/kg PO) q8–24h until serum progesterone level <2.0 ng/mL.
  • Supportive care including intravenous fluids as indicated.

Contraindications

Certain antibiotics may be contraindicated during pregnancy and nursing.

Precautions

  • Prostaglandin F2-side effects include panting, vomiting, defecation/diarrhea, and possibly hypotension. Side effects last 30–40 minutes and decrease gradually with subsequent doses, quickly metabolized in lungs.
  • Dopamine agonists-side effects include vomiting and nausea; can be controlled with antiemetics.
  • Strict monitoring of patients being managed medically for pyometra as patient may become endotoxemic or septicemic and require emergency OHE.
  • Stabilize patient prior to anesthetic induction for surgical management of pyometra.

Alternative Drug(s)

Aglepristone (Alizin®; 10 mg/kg SC, 2 doses given 24 hours apart)-progesterone receptor antagonist that may be used alone or concurrently with prostaglandin therapy for treatment of pyometra (currently not available in the United States).

Follow-Up ⬆ ⬇

Follow-Up

Patient Monitoring

Pyometra

  • Recheck serum progesterone until <2.0 ng/mL.
  • Recheck ultrasound after progesterone <2.0 ng/mL to monitor clearance of uterine fluid.
  • Recheck CBC and chemistry to monitor systemic health.

SIPS

  • Monitor PCV-depending on amount of blood loss.

Prevention/Avoidance

  • Puppy vaginitis-delay elective OHE until after first estrous cycle in cases of juvenile vaginitis; may avoid chronic vaginitis.
  • Avoid exogenous steroids (estrogens, progestins, androgens).

Possible Complications

Endotoxemia and septicemia may occur with pyometra or metritis.

Miscellaneous ⬆

Miscellaneous

Associated Conditions

Pyometra and cystic endometrial hyperplasia

Age-Related Factors

  • Increased risk for pyometra after each estrous cycle.
  • Neoplasia more common in older bitches.

Zoonotic Potential

  • Brucella canis-fluids and fetal tissue during abortion are highly contaminated with organisms.
  • Immunocompromised people are at highest risk. Animal caretakers and pathologists are at risk due to high exposure.

Pregnancy/Fertility/Breeding

  • Pyometra-grave prognosis for future fertility in bitches diagnosed with pyometra in conjunction with CEH, better prognosis (successful pregnancies have been reported) if overt signs of CEH not present and bitch is bred and becomes pregnant on next estrous cycle.
  • Neoplasia-poor prognosis for future fertility.
  • TVT-sexually transmitted disease; breeding should be avoided.
  • Brucella canis-sexually transmitted disease and grave prognosis for resolution of disease and normal fertility; should not be used for breeding.

Abbreviations

  • ACTH = adrenocorticotropic hormone
  • CEH = cystic endometrial hyperplasia
  • OHE = ovariohysterectomy
  • PCV = packed cell volume
  • TVT = transmissible venereal tumor

Suggested Reading

Feldman EC, Nelson RW. Vulvar discharges. In: Canine and Feline Endocrinology and Reproduction. St. Louis, MO: Saunders, 2004, pp. 909–913.

Johnston SD, Root Kustritz MV, Olson PN. Disorders of the canine vagina, vestibule, and vulva. In: Canine and Feline Theriogenology. Philadelphia: Saunders, 2001, pp. 225–242.

Purswell BJ. Vaginal disorders. In: Ettinger SJ, Feldman EC, eds., Textbook of Veterinary Internal Medicine, 8th ed. St. Louis, MO: Elsevier, 2010, pp. 1929–1933.

Purswell BJ. Vaginal disorders. In: Root Kustritz MV, ed., Small Animal Theriogenology. St. Louis, MO: Butterworth Heinemann, 2003, pp. 395–419.

Author Julie T. Cecere

Consulting Editor Sara K. Lyle

Acknowledgment The author and editors acknowledge the prior contributions of Leeah R. Chew and Beverly J. Purswell.

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