EQUINE | Equine Disease Update
EQUINE | Equine Disease Update
mid-1960s , it was suggested that horses should be dewormed for strongyles every six to eight weeks . This frequent deworming was thought 1 ) not to provide time needed for Strongylus spp . to mature , 2 ) to help decrease potential cyathostome egg deposition on pastures , and 3 ) not to allow time for ascarids to mature
High strongyle fecal egg counts indicate contamination of pastures and increased potential for ingestion of infective larvae by grazing horses . Thus , profiling the number of eggs per gram ( EPG ) of feces has been used in updating deworming schedules . Since Strongylus spp . are now rarely encountered , a deworming schedule can be more flexible . Unfortunately , there is no direct relationship between EPG values and cyathostome numbers .
A suggested deworming program is as follows :
• Establish a strongyle EPG profile for individual horses rather than deworming all horses ; a study of 1,114 Thoroughbred mares showed that one fecal sampling per horse was sufficient for establishing a strongyle EPG profile .
• For strongyles , use ivermectin or moxidectin alone or in combination with praziquantel twice a year — consider treating in the spring and fall . While benzimidazoles and pyrantel may be ineffective on cyathostomes , they may be efficacious in treating other parasite species .
• Treat foals every eight weeks of age for ascarid infection until they become yearlings ; oxibendazole is currently considered the drug of choice followed by fenbendazole .
• Control Strongyloides with ivermectin or oxibendazole and tapeworms with praziquantel or pyrantel pamoate / tartrate .
Contact : E . T . Lyons , PhD elyons1 @ uky . edu ( 859 ) 218- 1115 Maxwell H . Gluck Equine Research Center University of Kentucky Lexington , KY
Nocardioform Placentitis from an Epidemiological View
The outbreak of nocardioform placentitis in Kentucky ’ s 2011 foal crop was concerning to the equine industry . While not on as large a scale as seen in 2011 , we are seeing more cases of the disease in the 2017 foal crop in Kentucky than in the last several years ( Figure 1 ).
Nocardioform placentitis was first identified and characterized in the mid-1980s . Sequencing of the causative agents led to the term “ nocardioform ” due to the phylogenic relatedness of this large family of bacteria . The most common organisms have been identified as various Amycolatopsis and Streptomyces spp . and Crossiella equi . Outcomes from nocardioform placentitis can range from abortion , delivery of weak but viable foals , or delivery of normal foals ; all outcomes are dependent upon the severity of the placentitis . In some cases , foals are not viable and are euthanized . In 2011 , due to subsidies paid for placental submissions and examination , the response from the local equine industry was exceptional and the UKVDL witnessed the largest number of nocardioform placentitis cases submitted on record . The good news was that 70 percent of the 2011 cases resulted in viable foals . Concerns of increased incidence of nocardioform placentitis in the 2017 foal crop surfaced
• Volume 19 no 2 • June 2017 • 27