TitleImidocarb Dipropionate Lacks Efficacy against and Fails to Consistently Clear in Horses Co-Infected with .
Publication TypeJournal Article
Year of Publication2020
AuthorsSears, KP, Knowles, D, Dinkel, K, Mshelia, PW, Onzere, C, Silva, M, Fry, L
Date Published2020 Dec 10

Control of , the primary cause of equine theileriosis, is largely reliant on acaracide use and chemosterilization with imidocarb dipropionate (ID). However, it is currently unknown if ID is effective against , the recently identified second causative agent of equine theileriosis, or if the drug maintains effectiveness against in the presence of co-infection. The purpose of this study was to address these questions using ID treatment of the following three groups of horses: (1) five infected horses; (2) three - infected horses; and (3) three - infected horses. Clearance was first evaluated using nPCR for each sp. on peripheral blood samples. ID failed to clear in all three groups of horses, and failed to clear in two of three horses in group two. For definitive confirmation of infection status, horses in groups two and three underwent splenectomy post-treatment. The -nPCR-positive horses in group two developed severe clinical signs and were euthanized. Remaining horses exhibited moderate signs consistent with . Our results demonstrate that ID therapy lacks efficacy against , and - co-infection may interfere with ID clearance of .

Alternate JournalPathogens
PubMed ID33321715
PubMed Central IDPMC7764667
Grant List2090-320000-034-00D / / Agricultural Research Service /
No number / / Washington State University, College of Veterinary Medicine Equine Infectious Disease Research Program /