Efficacy and Side Effects of Low Single Doses of Cloprostenol Sodium or Dinoprost Tromethamine to Induce Luteolysis in Donkeys.
Authors: Segabinazzi Lorenzo G T M, Landers McKinsey, Kent Ava, Peterson Erik, Gilbert Robert, French Hilari
Journal: Journal of equine veterinary science
Summary
# Editorial Summary: Prostaglandin Dosing in Donkey Reproduction Equine practitioners have long extrapolated equine prostaglandin F2α protocols to donkeys due to scarce species-specific data, but donkeys may require substantially different doses to achieve effective luteolysis whilst minimising unwanted effects. Segabinazzi and colleagues conducted a rigorous crossover trial across 63 oestrous cycles in seven jennies, testing eight prostaglandin treatments (ranging from 250 µg down to 37.5 µg cloprostenol sodium, and 5 mg down to 0.625 mg dinoprost tromethamine) against an untreated control, with particular attention to corpus luteum regression, cycle length, and adverse reactions over 30 minutes post-injection. All active treatments significantly shortened the oestrous cycle and reduced corpus luteum volume within 24 hours compared to controls, but the critical finding was that the lowest doses—37.5 µg cloprostenol sodium and 0.625 mg dinoprost tromethamine—proved equally effective at inducing luteolysis whilst producing markedly fewer adverse effects than their higher-dose counterparts. For donkey practitioners managing fertility or synchronisation protocols, these data justify moving away from horse-equivalent dosing; using minimal effective doses will maintain reproductive efficacy whilst substantially reducing the discomfort and physiological stress associated with higher prostaglandin exposure, ultimately improving welfare and client satisfaction.
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Practical Takeaways
- •Donkeys require substantially lower prostaglandin doses than horses; extrapolating equine doses results in unnecessary side effects without improved efficacy
- •Minimum effective doses (cloprostenol 37.5 µg or dinoprost 0.625 mg) induce cycle shortening with better animal welfare and owner acceptance
- •When inducing estrus in jennies, use the lowest effective dose to minimize behavioral and physiological adverse effects while maintaining reproductive efficacy
Key Findings
- •All doses of cloprostenol sodium (250–37.5 µg) and dinoprost tromethamine (5–0.625 mg) effectively reduced estrous cycle length compared to control (P < 0.0001)
- •Corpus luteum volume decreased in all treated groups within one day of treatment (P < 0.05)
- •Lowest doses (cloprostenol 37.5 µg; dinoprost 0.625 mg) achieved luteolysis with significantly fewer adverse effects than higher doses
- •Adverse effects were dose-dependent and inversely correlated with prostaglandin analog concentration