Equine

Tackling the irritating problem of pinworm

vetreportJuly 30, 2013

With reports of persistent pinworm infection becoming more common¹, Zoetis is advising owners to remember to address this itchy issue as a part of their overall worm control programme.

Pinworm cases are now being reported more frequently in all age groups of horse rather than just youngsters². Although generally not considered to be as harmful as some other parasites, pinworm can prove to be a considerable irritation for both horse and owner as they can cause severe itching and subsequent rubbing.

Pinworm eggs are laid around the horse’s anus in a sticky substance, which is an irritant causing itching and tail rubbing. When a horse scratches itself, residue of this sticky substance can be left on surfaces such as fences or stable walls, which can lead to spread of infection. Contaminated feed and water bowls can also present a problem if they are shared around the yard.

Adult worms may be seen with the naked eye or a skin scrape or sticky tape test may be carried out by a vet in the area around the anus. Although a faecal worm egg count may show pinworm eggs it is not particularly reliable for this parasite.

It is thought that the changing behaviour of pinworm may be giving rise to increasing and more stubborn infections. Not only has a shortened time between infection and egg production been reported but the parasite also appears to be adapting immunologically. Traditionally pinworm was thought to be specific to young horses, with older horses appearing to acquire a degree of natural immunity but now infections are being seen regularly in older horses. One study reported that 4 out of 8 horses with pinworm were 17 years or older¹.

“Good stable and horse hygiene are imperative for the management of pinworm,” says Zoetis vet Wendy Talbot. “It’s crucial to break the lifecycle of the worms. Walls, fence posts and any surface that may have been contaminated should be scrubbed using a hard wire brush and a non-toxic disinfectant and feed and water sources should be thoroughly cleaned out, to prevent re-infection. In addition the area around the horses tail and anus should be washed with an appropriate cleanser to remove the eggs and soothe the area.  If you think your horse may be suffering from pinworm it’s important to talk to your vet to discuss the best worming programme.”

Stable Mate, the new App from Zoetis, makes it easy to manage your daily equine healthcare regime, including worming and it also provides handy healthcare advice. It is available from the iPhone App Store and Google Play Store: text Stable Mate to 80800 to download. To find out more visit www.wormingyourhorse.info

1 Reinemeyer, C., (2012) Anthelmintic resistance in non-strongylid parasites of horses. Veterinary Paristology; 185, 9-15

2. AAEP parasite control guidelines 2013