[Lacy's Mom]

This is from a vet book on prolonged bleeding so it is detailed, but you might find some helpful information in here.


B. PROLONGED PROESTRUS:

Condition characterized by proestrual bleeding lasting for more than 14 days. Sometimes up to 21-42 days, followed by a normal period in estrus, and ovulation. Fertility is normal if breeding occurs at estrus.

Diagnosis: Serial vaginal cytology reveals a slow progression in cellular maturation in vaginal smears. Bitch does not respond to teasing until several days to weeks after onset of proestrus (21-45 days). Hormonal assays may reveal a constant and moderately elevated estradiol concentrations for long periods, failure of LH release and failure of mature follicle to luteinize and no fall in estradiol levels. These findings suggest a slow rate of follicular maturation. Examination should be performed to rule out hypothyroidism, which can be characterized by abnormal proestrus bleeding (resting T4 assay; TSH stimulation test). In some cases vaginoscopy examination may cause trauma leading to continuous bleeding or in cases like Von Willebrandts disease. Cystitis or urolithiasis, neoplasm of the external genitalia (urethral carcinoma) and transmissible veneral granuloma should be ruled out.

Management: Use vaginal cytology and teasing to detect onset of estrus. Consider supportive treatment with hematinics to prevent anemia. Attempt to speed up follicular development by giving SC/IM injections of 50-100 IU of PMSG once every 3-4 days starting on day 3 or 4 of proestrus, until estrus or use FSH, is given at the dose of 25, 20, 15, 10, and 5 mg on consecutive days starting from day 10 after onset of proestrus. Give hCG (500-1000 IU) on day 1 of standing estrus, or GnRH (50-100 g) 6 hours apart to insure ovulation. Note that these treatments may induce superovulation.

C. VAGINITIS DURING PROESTRUS:

Characterized by malodorous vaginal discharge, large numbers of leukocytes and bacteria on vaginal smear and isolation of pathogenic bacteria on culture of a vaginal swab. Mating during estrus may result in failure of fertilization (spermicidal effect). Acute metritis, endometritis or possibly pyometra may occur after mating.

Diagnosis: Abnormal nature of proestrual discharge (malodorous). Presence of large numbers of leukocytes (lymphocytes and neutrophils) in vaginal smear. Large numbers of neutrophils with engorged bacteria. Inflammation (cherry-red appearance) of the vagina is obvious in vaginoscopy examination. Vaginal cultures reveal the presence of E. coli, Staph and Strep spp. In some instances Proteus mirabilis and Pseudomonas aeruginosa have been isolated in pure cultures in moderate to large numbers.

Treatment: Systemic antibiotic therapy for at least a week, plus local treatment, consisting of vaginal infusion of saline containing antibiotics after vaginal lavage. Various fluids, e.g., saline, or 1% Betadine solution have been used for lavage. Mating should be allowed if culture of vaginal smear at end of treatment is negative. Post breeding infusion with antibiotic may be used, i.e., breed day 1, infuse day 2, breed day 3, and infuse day 4, to prevent re-establishment of infection. Monitor bitch during post breeding period for signs of recurrence of infection, metritis or pyometra.


IV. PROBLEMS OF ESTRUS PERIOD LEADING TO INFERTILITY

A. PROLONGED ESTRUS PERIODS:

a. OVULATION FAILURE: Bitch exhibits estrus for more than the normal period (9-14 days) due to failure of ovulation. Sometimes bitch stays in estrus for more than a month. Clinically, the vulva is engorged, there is serous to mucoid vaginal discharge, and the bitch is continuously receptive. This may result in irritated vagina, due to numerous matings. Fertility in such cases is poor.

Diagnosis: Is based on history of prolonged estrus and cytological indications of estrus. If available, a hormone assay would indicate failure of LH release and only moderate increase in progesterone concentrations in plasma for several days.

Treatment: Immediate treatment should consist of administration of hCG 500-1000 IU IM or 10-20 IU/kg - repeat three days later or 25 to 50 g GnRH twice a day for 2-3 days to induce LH release and ovulation. Conception rates following these treatments are variable. On the subsequent estrus, administer 25-50 g of GnRH twice on day 1 of standing estrus. Mate starting from day 2 of estrus.

b. CYSTIC FOLLICLES: Ovarian cysts, usually follicular cysts are common in older dogs, lead to hyperestrogenism and prolonged periods in estrus. The onset of estrus signs occurs at unexpected time after previous estrus. Estrus behavior may be irregular, the bitch is attractive to male dogs, ride male dogs, but does not usually stand for mating. Animal is sterile. In long standing cases the bitch becomes irritable and bad tempered. The vulva is usually moderately swollen, and there is moderate serous discharge at vulval lips. In chronic cases there may be moderate mammary development. Vaginal cytology reveals predominantly superficial cells which persist over long duration. Vaginoscopy reveals typical signs of estrogenic influence. Abdominal palpation may detect presence of enlarged ovaries, but laparoscopy or laparotomy provide accurate diagnosis.

Treatment:

i. hCG 100-1000 IU given IM. Variable response.

ii. Twice daily administration of 50 g GnRH for 5 days; costly.

iii. Hemiovariectomy if only one ovary is involved (advised only in valuable bitches).

iv. Megestrol acetate (Ovaban) 10-20 mg orally daily for 1-5 days; then 2.5-10 mg (large bitches); or 2.5 mg (small bitches) orally daily until cytological signs of diestrus seen. Note danger of pyometra in 10% of treated cases. (least preferred)

v. Ovariohysterectomy if both ovaries involved.

c. OVARIAN TUMORS: These are usually associated with prolonged periods in estrus. Tumors are infrequent, the most common being granulosa cell tumors and cystadenocarcinoma. The incidence of ovarian tumors is low. Tumors are common in older bitches, but they have been diagnosed in young bitches. Granulosa cell tumors vary in size and are usually hormonally active.

Clinical signs: Include irregular, frequent or persistent estrus, engorged vagina, persistent serous to straw colored vaginal discharge, bilateral symmetrical alopecia of the upper flank area, and ascites. There may be also thinning of hair over abdomen and perineal region. In some cases there may be evidence of mammary growth but not lactation. Although the affected animal is attractive to male dogs, she does not stand for mating.

Diagnosis: Is based on abdominal palpation; and radiographic examination. Cytological examination of ascitic fluid for indications of neoplastic conditions and vaginal cytology that reveals predominantly cornified vaginal cells.

Treatment: Ovariohysterectomy or hemiovariectomy.

d. FALSE ESTRUS: There are certain conditions which are characterized by exhibition of estrual signs, which may persist for long periods. This can be a problem for the breeder, and these conditions must be recognized and differentiated from normal estrus.

i. For instance animals being treated with estrogens diethylstilbestrol (DES) for other conditions such as urinary incontinence, vaginitis or skin problems - may exhibit vulval enlargement, cornified vaginal epithelium, may be attractive to male dogs but nor flirt or stand for mating. Signs regress after withdrawal of treatment. Find out if bitch is on hormonal treatment.

ii. Bitches treated with estrogens as "mismate shots", usually exhibit estrus for several days, continue to be receptive after treatment.

iii. Chronic low grade vaginitis, traumatic vulvitis due to bite wounds, scratches - may be associated with vulval enlargement that may be confused with estrus. In cases of vulvitis the vulval hair is matted with discharge, and there may be perivulval dermatitis. The bitch is attractive to male dogs, but resents vulval inspection and will not stand for mating. Diagnosis is based on culture of bacteria from vaginal swab. Vaginal cytological characteristics of small non-cornified vaginal epithelial cells and large numbers of white blood cells.

iv. Bitches housed in groups in kennels may exhibit mild signs of estrus, when a group member comes in heat. Some may progress into full-blown estrus.

e. SPLIT ESTRUS: May be confused with prolonged periods of estrus. Most common in peripuberal bitches, but does occur in adult bitches. Condition is characterized by vulval swelling, proestral discharge. The bitch may be receptive for a few days then become non-receptive, (anestrus) for a few days followed by another period of receptivity. Others may exhibit proestrus and estrus activity in 3-4 weeks. This is due to failure to ovulate during the first period in estrus. The cause is not known but it has been seen in bitches after transportation; in bitches in training or endurance racing. It is common in bitches treated with FSH-like hormones to induce estrus. Abnormal hormonal patterns, follicular development may be a factor. Fertility is normal if the bitch is mated on the second period in estrus.