Equine Health Update EHU Vol 21 Issue 01 | Page 33

Equine Disease Quarterly | EQUINE tissues other than the pituitary, including ovarian tissues and the corpus luteum, but the roles of those receptors in fescue toxicosis, if any, have not been fully elucidated. The drug domperidone is frequently used in broodmares that are exposed to KY31 fescue and prevents or reverses the adverse reactions of ergovaline. Domperidone functions by binding to dopamine receptors, but rather than suppressing prolactin production, it competes with dopamine and allows for normal prolactin secretion. Because of the adverse health effects of common endophyte infected fescue in grazing animals, varieties of tall fescue which do not contain the fungal endophyte have been identified. Even though these endophyte- free varieties do not produce ergot alkaloids, animal performance is excellent. However, the plants do not persist well in pastures or compete well with other pasture grasses. More recently, endophyte strains that do not produce the alkaloids that are harmful to animals but still confer vigor and persistence to the plant, have been identified and inserted into tall fescue. These are called novel endophyte varieties of fescue, and some of these are commercially marketed as “Jesup Max Q,” “Texoma Max QII,” and “Baroptima Plus E34.” More recently, “Lacefield Max QII” was released by Dr. Tim Phillips in the Department of Plant and Soil Sciences at the University of Kentucky. The Alliance for Grassland Renewal is an association of seed companies, universities, and government agencies that regulate themselves by establishing certain quality control standards for novel endophyte tall fescues. For example, all seeds sold under the Alliance tag must be 95% pure, have 70% live (viable) endophyte, and have independent confirmation that the fescue variety does not cause fescue toxicosis in animals and will persist well under conventional grazing conditions. Although this article emphasizes the effects of ergot alkaloids on a dopaminergic receptor, it is important to remember that some of the alkaloids also bind to other receptor types, including adrenergic and serotonergic receptors, and thus may affect additional body systems. CONTACT: Karen McDowell, PhD [email protected] (859) 218-1104 Maxwell H.Gluck Equine Research Center Tim Phillips, PhD Department of Plant and Soil Sciences University of Kentucky Lexington, KY Equine Abortion: A Review of the 2016 and 2017 Breeding Seasons in Kentucky The loss of a developing fetus during pregnancy can be a frustrating, emotional, and costly experience for horse owners, farm workers, veterinarians, and the public. A thorough evaluation of the aborted fetoplacental unit (fetus and placenta) by a veterinary pathologist can help determine the cause of abortion, identify new, unusual, or foreign causes of fetal loss, rule out involvement by infectious agents, and aid in the epidemiologic monitoring of abortifacients (factors that can result in abortion). A two-year review of equine abortions, from the 2016 and 2017 breeding seasons, was conducted at the University of Kentucky Veterinary Diagnostic Laboratory to evaluate current abortion trends. Dates listed below indicate data for the respective breeding season, not calendar year. A total of 898 cases of equine abortion, 570 from 2016 and 328 from 2017, were evaluated. The majority of cases were considered sporadic and unrelated, except for one equine herpesvirus 1 abortion storm that was identified during the 2016 breeding season. Abortions • Volume 21 Issue 1 | March 2019 • 33