Reading the article on this site about AHF's will answer some of your questions.
About 85% of AHF's develop luteal tissue, and will therefore resolve with PGF2a. You would use a standard dose of the drug, such as would be used to induce estrus, or the double micro-doses that is also used to induce estrus.
hCG is given when a 3.5 cm follicle is present, and ovulation will occur within 48 hours in around 80% of mares.
If the AHF does not develop luteal tissue, it will not respond to PGF2a, and if that is the case, it is quite likely that the mare will not return to estrus until that AHF has resolved - typically 60-90 days.
Please note that opinions, product information, advice or suggestions posted on this bulletin board are not necessarily those of the management at Equine-Reproduction.com nor does the maintenance of the post position indicate an implicit or any endorsement of that information, opinion or product.
Further, although we have the greatest respect for the posters offering assistance here, you are advised to seek a consultation with your veterinarian prior to using information obtained from this board if it is of a veterinary nature.Proud to be sponsored and supported by: