Worming in the modern age

As we settle into the new year, many horse owners will be required to worm their horses in line with their yard schedule – often, this involves horses being chemically wormed regularly, regardless of their individual worm burden. Wormers of various descriptions have been in use since the mid-to late-90s (Potter, 2012) to control worm burdens in the horse, though the more recent school of thought is in favour of taking a more horse-centred approach.

At this time of year, horses are often wormed for tapeworm and roundworm. Lightbody et al (2016) found that almost 60% of the horses sampled had a tapeworm burden, although horses do not need worming for tapeworm unless they have a moderate–high burden (Kjaer et al, 2007). Roundworm infestations are more common in foals and horses under 2 years of age (Reinemeyer, 2009), and have been found in 31–61% of foals younger than a year old (Wilson, 2011). Treatment of both of these worms can be targeted with products containing praziquantel or an elevated dose of pyrantel (Reinemeyer et al, 2006; Slocombe et al, 2007).