Clinical use of dexamethasone for termination of unwanted pregnancy in dogs.
Dexamethasone was administered orally for 7.5 or 9.5 days to 80 pregnant bitches to terminate unwanted pregnancy at an outpatient clinic. Treatment was initiated at day 30-35 (n = 74) or day 45-50 (n = 6) of confirmed pregnancy using one of two dosages. In 62 bitches, dexamethasone was administered twice a day for 7.5 days increasing from 0.1 to 0.2 mg kg-1 over the first 2 days of administration and decreasing from 0.16 to 0.02 mg kg-1 over the last five administrations. The 18 remaining bitches were given dexamethasone twice a day for 9.5 days, at a dosage of 0.2 mg kg-1 for 7 days and then decreasing from 0.16 to 0.02 mg kg-1 over the last five administrations. Pregnancy was terminated without complication in 75 of the 80 bitches, and uterine contents were absorbed or aborted or both. Pregnancy was not terminated in five bitches treated for 7.5 days beginning at day 30-35 of gestation. In four of them parturition occurred at the normal time; in one, pregnancy was terminated by a second treatment. Pregnancy termination occurred at 7-15 days after the start of treatment. During ultrasonographic imaging of 13 bitches treated with dexamethasone, fetal deaths occurred between 5 and 13 days after the start of treatment. The side effects reported by the owners included polydipsia and polyuria, which were observed in all of the bitches and which disappeared when the treatment was discontinued. Some bitches also experienced vaginal discharge, restlessness, anorexia or emesis. At the first or second cycle after treatment, 20 bitches were mated and had normal pregnancies and normal litters. The results suggest that oral treatment with dexamethasone can be used to terminate pregnancy in bitches, but that in some cases the withdrawal of treatment after 8 days can result in retention of live pups and require a further treatment or the use of another abortifacient.
Wanke
M
M
Departamento de Teriogenología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Argentina.
Loza
M E
ME
Monachesi
N
N
Concannon
P
P
D000021:Abortifacient Agents, Steroidal; D000028:Abortion, Induced / Q000662:veterinary*; D000818:Animals; D003907:Dexamethasone; D004285:Dogs; D004334:Drug Administration Schedule; D005069:Evaluation Studies as Topic; D005260:Female; D005938:Glucocorticoids; D011247:Pregnancy; D014463:Ultrasonography; D014599:Uterus / Q000000981:diagnostic imaging
D000021:Abortifacient Agents, Steroidal; D005938:Glucocorticoids; D003907:Dexamethasone