An observational study was conducted to determine the commoness of Isospora suis oocysts in fecal samples from suckling piglets in Ontario. thee relationship between the presence of I. suis oocysts and diarrhea was also evaluated. Fifty farms and 709 litters of piglets were included in the study. Oocysts were detected on 70% of farms, with 187 litters infected. A litter of pigs that was positive for oocysts was significantly more likely to exhibit diarrhea than a litter that was negative. Management and housing factors were examined with respect to risk factors for the presence of I. suis.

Farms that did not use a detergent when cleaning farrowing crates were 10-times more likely to be positive for I. suis than those that used a detergent (P = 0.007). It was concluded that coccidiosis is a common problem on Ontario swine farms.

Neither the study by Mundt et al  nor the work described here revealed an association between the type of flooring in the farrowing crate environment and risk of I. suis infection. Possibly a much larger study designed to examine this particular aspect may be necessary before the role of flooring can be ruled out as an important risk factor for I. suis infection. The difficulty in interpreting the findings of this trial with regard to flooring type is that there were many different types of flooring designs and materials used on the 50 farms in the study. Overall, this study demonstrated that I. suis oocysts were present in the feces of suckling piglets on many Ontario farms and that the presence of oocysts was associated with diarrhea at the litter level. The work therefore suggests that coccidiosis is likely a common problem on Ontario pig farms.