Pinworm in horses
Yet again 2013 is proving
to be another year when equine Pinworm burden is becoming more widely reported
by UK horse owners. Pinworm (Oxyuris equi) is not generally thought to be
harmful as they pass through the intestine but more of a nuisance and an
irritant when the female pinworm lays her eggs around the horse’s anus. The
female can grow up to approximately 10cm in length and are white in colour.
They reside in the large intestine and attach themselves to the intestinal wall
to ingest the contents for food. Adults produce eggs approximately 5 months
after the initial infection. Eggs are laid around the anus and within a few
hours of being laid they develop into embryos and are infective in 4-5
days. On occasion the actual female worms can be seen in the process
of egg laying. Eggs find their way onto the pasture, into water and feed
supplies, on fences, stables and walls and onto grooming kits
Eggs are ingested by the
horse and L3 larvae are released in the small intestine, they then migrate to
the large intestine to develop into the mucosa to L4 larvae which then emerge
and mature into adults. The female adults then migrate from the large intestine
to the anus where they lay eggs in clumps in a sticky substance on the skin
causing irritation around the anus leading to tail rubbing. These can be
removed on a daily basis by cleansing the area around the tail, anus and
hindquarters with warm diluted disinfectant The pinworm likes to emerge in the
night to lay eggs so cleaning first thing in the morning is best. The recent
prevalence of pinworm burden which be in
some manner due to the different strategies recently introduced involving
worming horses so treating for pinworm needs to be considered when creating a
animal health plan..
Active ingredients that
treat for adult and pinworm larvae are Moxidectin, Ivermectin, Febendazole and
Mebendazole with Pyrantel treating adults only.
Not all brands are licensed
so care needs to be taken by checking the brand’s label.
Extra care should be taken
in the stable environment to help reduce the risk of re-contamination from
buckets, feed bowls, haynets and rugs etc. A thorough clean with a
disinfectant in these areas and most importantly the stable after removing all
bedding will help and is always a good idea in areas of animal care and
management. Do not share grooming brushes.
SH Wetherald
E-SQP
0844 808 6070
