Wednesday, 1 February 2012
Pinworm burden is becoming an increasing problem for
horse owners. Pinworm (Oxyuris equi) is not generally thought to be harmful but more of a nuisance and an irritant. However it is becoming more difficult to eliminate. The female can grow up to approximately 10cm in length and are white in colour. They reside in the large intestine and attach them selves to the intestinal wall to ingest the contents for food. UK
Adults produce eggs approximately 5 months after the initial infection which are found on the pasture, in faeces, contaminated water fences and walls.
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.
On occasion the actual female worms can be seen in the process of egg laying.
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. Do not share grooming brushes. A thorough clean with a heavy duty 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.
In some circumstances it may be possible for your vet to prescribe special preparations or treatments.
0844 808 6070