Comparison of three methods for termination of pregnancy in cats using a dopamine agonist and prostaglandin F2alpha

Abstract

This study compared the effect and efficacy of a natural prostaglandin F2alpha (PGF) a dopamine agonist (cabergoline; CBR), or the combination of PGF and CBR in pregnancy termination in domestic cats. after pregnancy confirmation by palpation and ultrasonography. Treatments on 15 cats (in two trials) were initiated between day 35 - 41 after first mating. Animals were assigned randomly to one of three treatment groups: CBR was given orally (n=10; 50 mcg/cat/day) for five consecutive days (day 0 to 5); PGF (n=10; 2.5 mg/cat/day, s.c.) for five consecutive days; or CBR and PGF (n=9, one cat was eliminated from the study). The queens were monitored by ultrasonography on days three and five during treatments and every day after completion of the treatments for three days to assess pregnancy status and fetal viability. The percentage of cats aborted was different (P < 0.05) among treatments. In the CBR group, six of ten cats aborted within three days after the last dose. Three days after the completion of the initial treatment, the only observed side effect was a mild bloody vaginal discharge. In the PGF group, only one of ten cats aborted during the three-day period following the completion of PGF treatment. Ultrasonography revealed viable fetuses (presence of heart beat) during and after treatment in the nine cats that did not lose their pregnancy. All nine cats in the CBR + PGF group aborted within three to six days after the initiation of the treatment (five cats after two doses, three cats after three doses, and one cat after five doses). These results indicate that a combination of CBR and PGF is a quick and effective method for pregnancy termination in cats. At 35 to 41 days after mating, treatment with CBR (at the above dose) alone was less effective in pregnancy termination compared with CBR+ PGF. Furthermore, PGF treatment alone, at least at this dose, was not effective in pregnancy termination in cats during 35-41 days after mating.