Do Foals, Yearlings Need Fecal Egg Counts of Zero?

Study foals and yearlings had good body condition scores and growth rates even when their fecal egg counts weren’t zero.

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Do Foals, Yearlings Need Fecal Egg Counts of Zero?
Good overall management practices can help compensate for the effects of parasitism. | Photo: iStock
Foals and yearlings are the groups of horses most susceptible to parasitic disease. As such, they’re also treated most intensively with deworming agents.

Traditional deworming practices dictate that young horses should be treated on a strict rotational program to eliminate the strongyles and ascarids that could cause serious disease. But do we really need to eliminate all parasites from young horses’ bodies?

Jennifer L. Bellaw, a PhD student at the University of Kentucky Maxwell H. Gluck Equine Research Center, in Lexington, and colleagues recently determined that this might not be the case. The team evaluated the impact of two deworming regimens—one rotational and one daily—on fecal egg counts (FECs), growth rates, and body condition scores in young Thoroughbreds.

The team determined that FECs were not significantly different between groups, but were significantly influenced by horse age, with strongyle counts increasing continually and ascarid counts peaking at 4.5 months of age

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Written by:

Katie Navarra has worked as a freelance writer since 2001. A lifelong horse lover, she owns and enjoys competing a dun Quarter Horse mare.

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