Luteal tissue blood flow and side effects of horse-recommended luteolytic doses of dinoprost and cloprostenol in donkeys.

This research investigated the effectiveness and side effects of administering cloprostenol and dinoprost, medications commonly used in horses, to donkeys. The study observed changes in luteal tissue and blood flow, as well as tracked side effects like sweating, abdominal discomfort, and diarrhea.

Research Design and Methodology

• The study involved eight donkeys (jennies) over sixteen cycles. These donkeys received cloprostenol and dinoprost, two drugs typically used for horses, at doses recommended for equine use.
• The research design was sequential crossover, meaning each donkey randomly received each drug in different cycles so that the effects of both drugs could be observed in each animal.
• The consequences on luteolysis (the regression of the corpus luteum, which is involved in reproductive cycles) and associated side effects were measured.
• Tools used include B-mode and Doppler ultrasonography, which were used to monitor changes in luteal tissue size and blood flow before and after the drug was administered.
• Progesterone concentrations were measured through radiometric assays over different points in time.
• Side effects, including sweating, abdominal discomfort, and diarrhea, were also tracked and scored over time.

Key Findings

• The blood flow in the luteal tissue increased significantly after administering the drugs. For dinoprost, the blood flow increased by 27% after 45 minutes and peaked at 49% after 3 hours. For cloprostenol, the increase was slower and less dramatic, with a 14% increase at 30 minutes and a peak at 39% after 5 hours.
• After hitting their peak, the blood flow decreased for both groups. After 24 hours, blood flow was reduced by 50% for dinoprost and 25% for cloprostenol.
• Both drugs caused a significant reduction in progesterone concentrations, with the drop starting faster for dinoprost than cloprostenol.
• Side effects varied between the two drugs. Dinoprost resulted in higher sweating scores, while cloprostenol led to greater abdominal discomfort and diarrhea scores.

Implications

• The research found that both dinoprost and cloprostenol effectively induced luteolysis in donkeys.
• However, each drug had distinct side effects, which provides useful information for veterinarians in prescribing medicine for donkeys.