Parascaris and cyathostome nematodes in foals: parasite in transit or real infection?

Faecal egg counts were performed in 187 foals of a large Polish stud farm between February and September 2007. Eggs of Parascaris equorum were present in faeces of 7% and those of cyathostomins in 13% of the foals aged less than 194 days. Information dealing with age of foals and/or efficiency of ivermectin treatment as well as the nematode parasite prepatent periods, it can be conducted that most of the infections recorded on the basis of faecal egg counts were false-infections in animals up to the age of six months, probably due to the ingestion of infected faeces of their dam or some other horses.