Prevalence of selected species of internal parasites in equids at necropsyin central Kentucky (1995-1999)

A survey to determine current prevalence of several species of endoparasite s in equids (n=350) at necropsy was conducted at the Livestock Disease Diag nostic Center in central Kentucky (1995-1999). Thelazia lacrymalis were fou nd in 42% of the 1- to 4-year olds (n=132), which was the only age group ex amined for these parasites. Five- to 30-year olds (n=157), examined for Onc hocerca spp. worms/lesions, had a prevalence of 24%. In greater than or equ al to 1-year olds (n=324), the infection rate for Gasterophilus intestinali s was 12% for second instars and 14% for third instars and for terophilus n asalis was 2% for second instars and 2% for third instars. For Anoplocephal a perfoliata (n=268 equids), prevalence was 52%. Data were compiled for the equids according to breed, age, sex, month of necropsy, and number of para sites. Arterial lesions caused by migrating Strongylus vulgaris larvae were observed in a low number (3 of 52) of equids. Specific examination for Par ascaris equorum revealed that 46% of 13 weanlings and 10% of 20 older horse s were infected. Anoplocephala magna were found in one of the weanlings. Co mpared to previous studies (about 15-25 years ago) in Kentucky, the present survey indicated the genera Onchocerca and Gasterophilus greatly declined but Thelazia, Anoplocephala, and Parascaris did not. (C) 2000 Elsevier Scie nce B.V. All rights reserved.