Gastrointestinal nematode prevalence and fecal egg counts in beef cattle from western Canada.

Fecal samples were collected from cows (n = 1458), calves (n = 1188), and replacement heifers (n = 921) between 2012 and 2014 from 199 herds and generalized estimating equations were used to predict mean fecal egg counts and prevalence of egg-positive samples. Replacement heifers had the highest prevalence of Trichostrongylid-type eggs at 83% [95% confidence interval (CI): 78% to 87%], and cows had the lowest at 75% (95% C: 70% to 81%). Nematodirus spp. was most frequently present in calves [predicted prevalence: 34% (95% CI: 28% to 40%)]. Mean fecal egg counts were highest in calves with 5.9 (95% CI: 3.9 to 7.8) Trichostrongylid-type eggs per gram (EPG) of feces and 1.0 (95% CI: 0.7 to 1.4) Nematodirus spp. EPG. Although mean egg counts were low to moderate, the high prevalence highlights the need to further investigate the epidemiology of gastrointestinal nematodes in western Canada. This is particularly relevant considering management changes, increasing herd sizes, climate change, and threatening anthelmintic resistance. Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.