The induction of parturition in the bitch using sodium cloprostenol

The objectives of this studies were to determine a continuous low-dose trea tment regimen for the administration of sodium cloprostenol to the bitch th at did not cause polydipsia, and whether this treatment would induce normal and timed parturition in bitches during late pregnancy. Nonpregnant greyho und bitches (n=18) received sodium cloprostenol subcutaneously, via a minio smotic pump, at dose rates of 0.875 to 4.5 mu g/kg/24 h, for 7 days (Days 0 to 7). Daily water intake was measured from Day -2 to Day 9. Polydipsia wa s observed in bitches treated with the higher dose rates but not in bitches treated with the lowest dose rate of 0.875 mu g/kg/24 h. In the second exp eriment, pregnant greyhound bitches received sodium cloprostenol at dose ra tes of 1 (n=4), 2 (n=1) and 3 mu g/kg/24 h (n=1), on Day 57 of pregnancy. P olydipsia was observed in bitches treated at the higher dose rates of 2 and 3 mu g/kg/24 h, but not in the bitches treated at the Lower dose rate of 1 mu g/kg/24 h. These treatments resulted in the successful induction of parturition. Partu rition was associated with a decrease in plasma progesterone concentrations , a reduction in body temperature, and an increase in plasma concentrations of 13,14-dihydro-15-keto prostaglandin F-2 alpha. The first puppy was born 37.7 +/- 2.9 h after the start of treatment (range 28 to 46 h). The durati on of whelping was approximately 15.7 +/- 2.2 17 (range 10 to 24 h). The li tter size was 9.2 +/- 0.8 pups (range 6 to 12 pups), and the puppy survival rate was 6.0 +/- 0.8 per litter (range 4 to 9 pups). This study demonstrat ed that the administration of sodium cloprostenol in continuous low dose fo r 24 h is an effective treatment for the induction of parturition in bitche s during late pregnancy. This treatment resulted in the birth of healthy pu ps, with minimal or no side effects to the bitch. (C) 2000 by Elsevisr Scie nce Inc.