There are many types of worms, and most use the horse as a host during their lifecycle. The amount of damage to the horse depends on the horses’ immune status, number of worms present and type of worm.
Large Redworms (strongyles)
Not as common as it used to be. Larval stage of the lifecycle is of most concern, as it migrates through the blood vessels. The migration can cause damage to blood vessel walls and can cause blood clot formation. Disruption to the blood supply can cause colic and in some rare cases death.
Small Redworms (cyathostones)
These are the most common internal parasite of the horse. The lifecycle takes a few weeks from larvae ingestion to adult laying eggs. These worms can hibernate in the form of cysts in the gut wall, this is when they become difficult to treat.
Large Roundworms (ascarids)
These worms usually only affect foals and young horses. Adult horses are not normally affected as immunity is developed with age. Adult large roundworms can grow up to 50cm in length. In foals and young horses they can cause poor growth, digestive problems, respiratory problems and even death.
Found in horse’s gut, usually found between the small and large intestine. Severe tapeworm infections can cause loss of condition, digestive disturbances, coil and death.
Usually a problem seen in the summer time for grazing horses. The bot flies lay small sticky eggs on the coat. Usual areas include forelimbs, abdomen or shoulder. As the horse grooms itself (or another horse) it causes the eggs to hatch and the larvae to enter the stomach. Once there the larvae attach to the gut lining. Daily removal of the eggs from your horse will disrupt the lifecycle.
It is thought donkeys are the natural host of lungworms but horses can be affected with lungworms also. It occurs more likely in horses that share grazing with donkeys. Donkeys tend to tolerate a large infestation of lungworms unlike horses which show obvious respiratory signs – coughing. NOTE – horses and donkeys can live together if a worming programme is in place.
Worm Egg Counts
Worm egg counts are used to minimise the risk of worm resistance and allow a targeted approach to the use of wormers. We send our faecal samples to an external lab for results. Worm egg counts should be performed 8-10 weeks after using a worming product.
Please note small redworms in the gut can’t be detected with this method. Also tapeworms aren’t detected by worm counts, these are detected by a tapeworm antibody test (blood test)
There are many different worming products available, please contact the surgery and one of the veterinary surgeons will best advise you.