Horse Worming Chemicals

See also: Horse Wormers (Manufacturers) | Horse Worming Schedule| Horse Worms

Horse Worming Chemicals
Horse wormers are made up of three main groups of chemicals Macrocyclic Lactones, Tetrahydropirimines and Benzimidazoles.

Contact your veterinary surgeon who will be able to advise you on an appropriate worming programme for your horse.

Macrocyclic Lactones
- Macrocyclic Lactones have the active ingredients Ivermectin and Moxidectin
- Moxidectin based wormers can be used to treat for encysted redworm, small and large strongyles, roundworms, pinworms, hair worms and bots.
- Ivermectin based wormers can be used to treat small strongyles, bots, large strongyles, Pinworms, Roundworm, Lungworm, stomach worms, neck and intestinal threadworm.
Tetrahydropirimidines
- Tetrahydropirimidines have the active ingredient Pyrantel.
- Pyrantel based wormers can be used for the treatment of Tapeworm in March and September.
Benzimidazoles
- Benzimidazoles have the active ingredients Fenbendazole, Mebendazole and Oxibendazole.
- A 5 day course of a Fenbendazole based wormer can be used in November and February for the treatment of various stages of encysted cyathostone larvae.
- Fenbendazole also controls large strongyles, small strongyles, Pinworms and Roundworm.
The drug Praziquantel must be used with one of the three chemical groups above in the treatment of Tapeworm and other worms.

Here is an example of how these chemical groups are used during a yearly worming programme:

September
- The chemical Pyrantel embonate can be used for the treatment of Tapeworm
Late October or early November
- A 5 day course of Fenbendazole can be used to treat for small Redworm, migrating large redworm larvae, adult redworm and encysted redworm.
December
- The chemical Ivermectin or Moxidectin can be used for the treatment of Bots as well as for large and small strongyles, roundworms and pinworms for example.
February
- A 5 day course of Fenbendazole can be used to treat for small Redworm, migrating large redworm larvae, adult redworm and encysted redworm.
March
- The chemical Pyrantel Embonate can be used for the treatment of Tapeworm.
April to August is the grazing season
- During the grazing season of April to August choose one chemical group, for example if you chose Macrocyclic Lactones as your chosen group you will be using wormers which contain Ivermectin or Moxidectin at the intervals suggested by the manufacturer during the grazing season.
- The chosen chemical group should be changed each year so for example the following year between April and August your chosen chemical group could be Benzimidazoles so your wormers would contain the ingredients Fenbendazole, Mebendazole or Oxibendazole