THE DISTRIBUTION OF ANOPLOCEPHALA-PERFOLIATA IN THE INTESTINE OF THE HORSE AND ASSOCIATED PATHOLOGICAL-CHANGES

The intestinal tracts of 130 horses were examined for infection with A noplocephala perfoliata at necropsy. Fifty horses (38.5%) harboured th e tapeworm, and the site of attachment of each worm was recorded using predetermined anatomical landmarks. The worms were attached in four r egions of the gastrointestinal tract: 17% of the worms were found at t he ileocaecal junction, 81% on the caecal wall, 1.7% in the terminal i leum and 0.2% in the ventral colon. The severity of lesions produced a t the sites of attachment was related to the number of worms attached. Due to the small area of the ileocaecal junction, worms at this site were attached in close proximity, resulting in more severe lesions. Th e major features of the lesions included ulceration, diphtheritic memb ranes and thickening of the mucosa, submucosa and lamina propria. Ther e was an increase in the number of eosinophils and a decrease in the n umber of lymphocytes present at the sites of lesions. (C) 1997 Elsevie r Science B.V.