Eyeworms (Thelazia lacrymalis) in one- to four-year-old Thoroughbreds at necropsy in Kentucky (1984 to 1985).

This is a study on the prevalence of a type of eyeworm (Thelazia lacrymalis) in one- to four-year-old Thoroughbreds in Kentucky between 1984 and 1985. The findings indicate that a significant percentage of the examined horses, around 43%, were infected with eyeworms.

Introduction and Methods

• The research was conducted over a period of one year, from March 1, 1984, to February 28, 1985.
• The subjects of this study were one- to four-year-old Thoroughbreds in Kentucky, whose eyes were examined post-mortem for the presence of the eyeworm Thelazia lacrymalis.
• A total of 189 horses were examined, which included 88 males, 90 females, and 11 geldings.

Results

• The results showed that Thelazia lacrymalis was found in a significant percentage of the horses examined.
• The prevalence of the eyeworm in the examined horses varied by their age: 45% of one-year-old horses, 26% of two-year-old horses, 45% of three-year-old horses, and 50% of four-year-old horses were infected.
• Overall, 43% of the examined horses were infected with eyeworms.

Comparative Analysis

• The prevalence of eyeworms in this study was compared with the findings of two previous studies conducted in Kentucky, which also examined horses of similar ages at necropsy.
• These studies were conducted in the period of 1975 to 1976, and in 1979.
• The findings of the current study were found to be comparable to the previous studies, with the exception of a lower percentage of infections in two-year-old Thoroughbreds in the current study.