Follicular Cysts and Nymphomania
Follicular cysts are rare. They result in prolonged secretion of estrogen, continued signs of proestrus or estrus, and attractiveness to males. Ovulation may not occur during this abnormal estrous cycle. Follicular cysts should be suspected in any bitch showing clinical manifestations of estrus for 21 days, or when proestrus plus estrus have lasted for 40 days. Estrous cycles due to follicular cysts in queens may be difficult to differentiate from normal, frequent cycles. An estrogen-secreting ovarian tumor is the other diagnostic consideration.
Ovariohysterectomy is curative. If the animal is to be bred, ovulation may be induced by using gonadotropin-releasing hormone (Gn-RH) at 25 µg (total) in bitches =11 kg and at 2.2 µg/kg in bitches >11 kg. In queens, the dose is 25 µg (total), IM, for 2 days. Breeding should probably continue throughout the prolonged estrus because the time of ovulation is unknown. Gn-RH is not an effective treatment for ovarian tumors.
Acute infection of the uterus is usually a postpartum disorder that may be associated with abortion, fetal infection, retained placentas, obstetrical manipulation, or ascending infection after apparently normal parturition. Uncommonly, metritis occurs after natural mating or artificial insemination. Escherichia coli is the most common bacterium isolated from the infected uterus; streptococci, staphylococci, Proteus , and others are isolated less frequently.
Animals with metritis are usually quite ill with signs of fever, lethargy, and inappetence. A purulent, foul-smelling vaginal discharge is usually found. The dam may neglect the young. The pups become restless and cry incessantly. Acute metritis should be considered in any postpartum animal with signs of systemic illness or an abnormal vaginal discharge. A large, flaccid uterus may be palpable. Radiographs should be taken to determine if fetuses or placenta are retained. The hemogram may show a leukocytosis with a left shift.
Therapy includes supportive care, IV fluids, and broad-spectrum bactericidal antibiotics, preferably those effective against E coli . Prostaglandin F2a (0.1-0.25 mg/kg body wt, SC, for 2-3 days) or oxytocin (5-20 u in bitches, 2-5 u in queens, IM) may help evacuate the uterine contents. Ovariohysterectomy is indicated after initial stabilization if the animal is extremely ill or if future reproduction is unimportant. Otherwise, it should be considered an elective procedure to be performed when lactation has ceased.
Difficult birth may result from myometrial defects, metabolic abnormalities such as hypocalcemia, inadequate pelvic diameter, insufficient dilation of the birth canal, fetal hormone (corticosteroid) deficiency, fetal oversize, fetal death, or abnormal fetal presentation and posture.
Dystocia should be considered in any of the following situations: 1) an animal has a history of previous dystocia or reproductive tract obstruction; 2) parturition does not occur within 24 hr after the drop in rectal temperature (to <100°F [37.7°C]); 3) strong abdominal contractions for 1-2 hr without passage of a puppy or kitten; 4) active labor for 1-2 hr without delivery of subsequent puppies or kittens; 5) the resting period during active labor exceeds 4-6 hr; 6) the bitch or queen is in obvious pain (crying, licking, or biting the vulva); 7) there is a black, purulent, or hemorrhagic vaginal discharge; 8) there are signs of systemic illness; or 9) gestation is prolonged.
To determine the appropriate therapy, the cause of the dystocia (obstructive versus nonobstructive) must be determined and the condition of the animal assessed. A thorough history regarding previous parturitions, pelvic trauma, and breeding dates is desirable. The animal should be examined for signs of systemic illness which, if present, may necessitate immediate cesarean section. The normal vaginal discharge at parturition is a dark green color; abnormal color or character indicates immediate attention is needed. A sterile digital vaginal examination should be performed to evaluate the degree of cervical dilation, the patency of the birth canal, and the position and presentation of the fetus(es). Radiography or ultrasonography can be used to determine the presence and number of fetuses, as well as their size, position, and viability.
Medical management may be considered when the condition of the dam and fetuses are stable, when there is proper fetal position and presentation, and when there is no obstruction. Oxytocin (3-20 u in bitches, 2-5 u in queens) given IM up to three times at 30-min intervals, with or without 10% calcium gluconate (3-5 mL, IV slowly, once) may be given in an attempt to promote uterine contractions. If no response follows, a cesarean section should be performed.
Forceps may be used (carefully) to remove dead fetuses or to facilitate delivery of malpresented or partially delivered fetuses. Gentle manipulation and adequate lubrication must be used to prevent injury or death to living fetuses. Episiotomy may be helpful.
Surgery is indicated for obstructive dystocia, if dystocia is accompanied by shock or systemic illness, for primary uterine inertia, when active labor is prolonged, and/or if medical management has failed.
In vaginal hyperplasia, a proliferation of the vaginal mucosa, usually originating from the floor of the vagina anterior to the urethral orifice, occurs during proestrus and estrus, as a result of estrogenic stimulation. The most common sign is a mass protruding from the vulva. Initially, the mass is smooth and glistening, but with prolonged exposure, the surface becomes dry and fissures develop, so it has a tongue-like appearance. A slight vaginal discharge may be present. Although the hyperplastic tissue originates near the urethral orifice, dysuria is uncommon. Vaginal hyperplasia interferes with copulation. Reluctance to breed or failure of intromission may be the only clinical sign if the hyperplastic tissue is contained within the vaginal vault. Vaginal hyperplasia resolves spontaneously as soon as estrogen declines. The diagnosis is made by the history (stage of the estrous cycle) and examination of the vagina. Estrogenic stimulation could be confirmed by vaginal cytology if the history is questionable. The two differential diagnoses are vaginal prolapse (excluded by the history and physical findings) and neoplasia (excluded by biopsy).
If the hyperplastic tissue is not causing problems, therapy is not indicated. However, if it protrudes from the vulva, it should be kept clean and moist and an antibiotic ointment applied. An Elizabethan collar may be necessary to prevent self-trauma. These animals may be bred by artificial insemination. The hyperplasia regresses as soon as the follicular phase of the estrous cycle has passed. Rarely, the hyperplasia recurs at parturition, presumably associated with a burst of estrogen. Submucosal resection may be necessary if the mass is extremely large or if mucosal damage is extensive. Recurrence is common even after surgical resection. Vaginal hyperplasia resolves within days of removal of estrogen. Ovariohysterectomy hastens resolution and prevents recurrence and is the treatment of choice.
Inflammation of the vagina may occur in prepubertal or mature (intact or spayed) bitches. It is rare in queens. Vaginitis usually is due to bacterial infection, which may be secondary to conformational abnormalities such as vestibulovaginal strictures. Viral infection (eg, herpes), vaginal foreign bodies, neoplasia, hyperplasia of the vagina, androgenic steroids (eg, mibolerone), or intersex conditions also may cause vaginitis.
The most common clinical sign is a vulvar discharge. Licking of the vulva, attraction of males, and frequent micturition also may be seen. Signs of systemic illness are not present, and the hemogram and biochemical profile are normal. The absence of these abnormalities helps differentiate vaginitis from open-cervix pyometra, the most important differential diagnosis. The diagnostic evaluation should include a digital examination of the vagina, vaginoscopy, cytology and culture of the exudate, and if necessary, abdominal radiographs or ultrasonography to evaluate the uterus. An anterior vaginal culture may be obtained using a guarded sterile culture swab. The vagina contains normal bacterial flora; therefore, culture results must be interpreted cautiously. A heavy growth, especially of one organism, is probably more significant than a light growth of several organisms.
Predisposing factors such as foreign material or anatomic abnormalities should be corrected. Bacterial infection may respond to local treatment (ie, vaginal douches). Systemic, broad-spectrum, bactericidal antibiotics may be needed for persistent infections. Prepubertal animals often do not require treatment because the vaginitis nearly always resolves with the first estrus. Therefore, it may be wise to delay elective ovariohysterectomy in affected animals until after their first estrous cycle.