Deworming Guide



Tapeworms (Anoplocephala) have a life cycle that takes roughly six months to complete, so a twice yearly dose of Praziquantel is sufficient to control  Tapeworms.They are to be found in the large gut at the junction of the small intestine,caecum and colon. If not controlled they may cause an obstruction.

Large Roundworms (Parascaris Equorum) has a life cycle of under 10 weeks and is a pathogen of young horses and foals. They need to be treated for this parasite from 1 month of age and a certain amount of immunity to this worm develops at about 1 year of age.

Bots (Gastrophilus) are the larvae of the Bot Fly.These Bot flies lay their eggs on different parts of the horse’s body and the eggs are then ingested by the horse. The larvae spend approximately nine months attached to the stomach lining of the horse before passing out with the manure and maturing into adult Bot Flies. Adult Bot Flies are active from late Spring to Late Autumn.

Deworming Schedule

Routine wormer: July - September  and November - March

Tapeworm: October, April

Encysted Strongyles (Cyathostomes): May to August

Bots: June (First Frost) and November

bilitated horses.


Risk Group

Exposure Cycle

Large & Small Strongyles

(Blood worms or Red worms)

All horses

Young horses are particularly susceptible to large infestations.



(Large roundworms)

All horses

Mares should be treated before foaling.



All horses



All horses

Early spring & late autumn

Probiotics in conjunction with wormers

It's a really good idea to give the horse probiotics, especially a day or two after you give them worm medicine.The probiotics are beneficial intestinal bacteria which are natural to the horses instestines.  These can get killed off by worm medicines, stressful conditions, etc., and when given to the horse by mouth or added to the horses feed will multiply in the horses gut, helping them digest their food, and their adequate presence in the gut makes no room for infective bacteria.



Internal parasites are a major
threat to the health, strength
and vitality of every horse.