EFFECT OF SEASON, SEX, AND AGE ON PREVALENCE OF PARASITISM IN DOGS FROM SOUTHEASTERN WISCONSIN

Examination of fecal samples from 309 animal shelter dogs in Milwaukee County, Wisconsin, was made to evaluate the effect of season, host ag e, sex, and care status on the prevalence of single and multiple infec tions of intestinal parasites. One or more species of parasite were id entified in 42% of fecal samples. Intestinal parasites were present in all months of the year, but prevalence was higher in warmer than in c older seasons. Toxocara canis was the most common parasite egg recover ed (21.4%). Other helminth eggs recovered were Ancylostoma sp. (11.3%) , Trichuris vulpis (8.7%), and Toxascaris leonina (4.2%). The protozoa ns Isospora canis (5.2%) and Giardia lamblia (4.5%) also were recovere d. No cestode eggs were seen during the study. There was no significan t difference in overall prevalence between 168 male (41.7%) and 141 fe male (41.9%) dogs. Ascarids were more common in younger dogs. Hookworm prevalence also decreased with increasing host age. Male dogs were mo re frequently infected with hookworms. Whipworms were found less often in very young and in older dogs. Multiple infections comprised 27% of positive fecal samples but were not clustered by season. Neutered ani mals of both sexes were infected less often than were intact animals. Stray animals were significantly more frequently infected than were pr eviously owned dogs.