Case information:
You are presented with a 2 year old intact female Rottweiler with a complaint of persistent estrus. This bitch had cycled regularly every 6 months but has been exuding serosanguinous vulvar discharge and attracting the intact male dog in the household for over 7 weeks.
On physical examination, rectal temperature, pulse and respiratory rate are normal. The bitch's vulva is swollen and drops of serosanguinous, odorless discharge fall on the floor as you examine her. All else is normal.
Question:
What are rule-outs for persistent estrus in the bitch?
Answer:
- Ovarian follicular cyst
- Granulosa cell tumor
Question:
What diagnostic tests would you like to run to differentiate these disorders?
Answer:
Vaginal cytology can be used to verify whether the serosanguinous vulvar discharge is associated with estrogen secretion. Abdominal ultrasound does not permit definitive diagnosis but generally granulosa cell tumors are larger than cysts and may be more segmented into compartments. Below is a vaginal cytology specimen, and ultrasound images of an ovary and the uterus.
Question:
What is your interpretation of these findings?
Answer:
The vaginal cytology is cornified, indicating significant secretion of estrogen. A large cystic structure is present on the ovary. The endometrium is visible, suggesting cystic endometrial hyperplasia is present.
Question:
What is your plan for treatment?
Answer:
Ovariohysterectomy is the treatment of choice for most dogs. However, this is a valuable breeding bitch that the owners hope to breed in the future. Medical therapy involves induction of ovulation, either with gonadotropin releasing hormone (GnRH) or human chorionic gonadotropin (hCG).
Question:
To what disease may this bitch be predisposed after induction of ovulation?
Answer:
Pyometra. Cystic endometrial hyperplasia (CEH) is the primary pathology of pyometra, with infection the secondary component.
Case Outcome:
The bitch was treated with GnRH to no effect, then with hCG to no effect. Surgical removal of the affected ovary was recommended but vaginal cytology became non-cornified about 10 days after hCG administration, suggesting luteinization of the ovarian follicle(s) had occurred. The bitch presented about 3 weeks later with pronounced purulent vulvar discharge and was diagnosed with pyometra. The owners elected ovariohysterectomy at that time; CEH was grossly visible at the time of surgery.
