| The cestode Anoplocephala perfoliata is known to cause fatal colic in horses. The epidemiology of the cestode has rarely been evaluated in Canada. I detected A. perfoliata eggs in 4-18% of over 1000 faecal samples collected over 2 years. Worm intensity ranged from 1 to >1000 worms. Pastured horses were infected more often than non-pastured horses, especially in western Alberta, likely reflecting their higher rates of exposure to mite intermediate hosts. In a comparison of diagnostic techniques, fecal egg counts were the least accurate. Western blot analysis had the highest sensitivity to detect antibodies to the cestode (100%), but had lower specificity. A serological enzyme-linked immunosorbent assay (ELISA) had a lower sensitivity (70%) for detection of antibodies than described in previous studies. A coproantigen ELISA had 74% sensitivity and 92% specificity, and a positive correlation was found between antigen concentration and cestode intensity. The latter is important because it implicates the utility of this method for accurate clinical diagnosis and epidemiological studies. |
