Luteotrophic action of prolactin in dogs and the effects of a dopamine agonist, cabergoline.
The purposes of this study were (1) to evaluate the effects of cabergoline (1.65 micrograms kg-1 injected subcutaneously for 5 days) on plasma progesterone concentrations in the pregnant bitch; (2) to assess its clinical value in terminating pregnancy in the bitch, and (3) to evaluate its side effects. Cabergoline, given to pregnant bitches, had an anti-prolactinic action and induced abortion. Plasma progesterone concentrations were reduced to below that value necessary to maintain pregnancy (2 ng ml-1 in all cases when the treatment was given 40 days after the first mating, and in four out of six cases when given from 30 days after mating). Fetal resorption occurred in 75% of cases, without clinical sign other than some vaginal discharge. The efficiency of cabergoline treatment can be monitored by plasma progesterone determination: concentrations < 2 ng ml-1 5 days after the start of treatment indicate success; in the event of failure, another treatment can be started. Ultrasonography was not always useful in predicting abortion, as in some cases this was not preceded by signs of fetal distress. The use of cabergoline as an abortifacient in the bitch appears to be of interest. Its efficacy in the second half of gestation, which is attributable to its antiprolactinic action, has been widely demonstrated and the probable multifactorial regulation of corpus luteum activity during the first half of gestation has suggested that earlier luteolysis could certainly be obtained without any side effects through a multiple approach, using different, mutually potentiating, luteolytic agents.(ABSTRACT TRUNCATED AT 250 WORDS)
Onclin
K
K
Department of Small Animal Reproduction, Veterinary College, University of Liège, Belgium.
Silva
L D
LD
Donnay
I
I
Verstegen
J P
JP
D000019:Abortifacient Agents; D000028:Abortion, Induced / Q000662:veterinary*; D000818:Animals; D000077465:Cabergoline; D003340:Corpus Luteum Maintenance / Q000187:drug effects; D004283:Dog Diseases / Q000139:chemically induced; D004285:Dogs / Q000502:physiology*; D015259:Dopamine Agents / Q000494:pharmacology*; D004873:Ergolines / Q000494:pharmacology*; D005260:Female; D005327:Fetal Resorption / Q000139:chemically induced / Q000662:veterinary; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000187:drug effects*; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000502:physiology*
D000019:Abortifacient Agents; D015259:Dopamine Agents; D004873:Ergolines; D011374:Progesterone; D011388:Prolactin; D000077465:Cabergoline