A cross-sectional survey of gastrointestinal parasites with dispersal stages in feces from Costa Rican dairy calves

摘要

A cross-sectional study was carried out to determine the prevalence of gastrointestinal parasites and lungworm nematodes in dairy calves from five different ecoclimatic areas of Costa Rica. Also intensity of infection of nematodes was determined. In order to describe management practices and anthelmintic control, a questionnaire was applied in 73 farms. The influence of area, farm, host (breed, age) and ecological factors (low and high rainfall period) upon eggs per gram feces (epg) of gastrointestinal nematodes (GIN) and first larval stage counts (L1) of Dictyocaulus viviparus were investigated. Furthermore, association of host, ecological and management risk factors to the prevalence of gastrointestinal parasites and D. viviparus were analyzed. The most prevalent GIN, cestodes and protozoan identified in dairy farms were similar in all areas studied. Strongylidae was the most prevalent parasite group detected, represented mainly by Haemonchus spp. and Cooperia spp., whereas Ostertagia spp. and Mecistocirrus digitatus were barely found. The most prevalent protozoan was Eimeria spp. The questionnaire applied to producers revealed the following management practices: weaning age of calves 1-4 months (52.1%), semi-confinement of calves upon 5-8 months of age (41.1%), number of paddocks used for calves <10 (57.5%), first deworming of calves at ages >= 15 days (74.70%) and deworming of calves at intervals >60 days (52.1%). Anthelmintic products were changed in 56.1% of the farms at intervals between 13 and 24 months. Although 91.8% of the farms had veterinary assistance, the majority performed parasite control regimes according to the criteria of the producers (66.7%). Common practices were the dispersion of animal feces on the pastures (64.4%) and use of disinfectant in the milking room (63.4%). The analyses of variance showed significant influence (p<0.05) of age, rainfall period, interaction of rainfall period on area (rainfall period x area) and nested effect of farm within area [farm (area)] on epg of Strongylidae; age, area, rainfall period x area and [farm (area)] on epg of Strongyloides papillosus; age, rainfall period and farm (area) on epg of Trichuris spp.; rainfall period, rainfall period x area and [farm (area)] on L1 of D. viviparus. The logistic regression analyses determined area, semi-confinement, management of feces, use of disinfectant in the milking room as risk factors for the presence of Strongylidae, S. papillosus and Trichuris spp; rainfall, age, paddock numbers for D. viviparus; and area, age, veterinary assistance, deworming program, age at first deworming and use of disinfectant in the milking room for Eimeria spp. and Buxtonella sulcata