Horse Drench

Horse Drench

Horse drenches, also known as horse wormers or by their technical name of anthelmintics, play a crucial role in maintaining horses’ health and wellbeing. They are designed to combat internal parasites that can wreak havoc on a horse’s digestive system, causing a decline in overall health as a result. Whether horses are in paddocks or stables, parasite infestations can be deeply damaging – therefore, employing a good wormer is essential. Explore horse wormers and horse paste from brands like Zoetis and Coopers Animal Health with Specialist Sales. 

How do horse wormers work? 

There are four key types of horse wormers available to horse owners, each distinguished by their active chemicals – benzimidazoles (e.g., fenbendazole, oxfendazole), pyrantels, macrocyclic lactones (e.g., ivermectin, moxidectin) and praziquantel. Some antiparasitic drenches rely on just one of these ingredients, whereas others may incorporate a combination to increase efficacy and address resistance. 

Perhaps the most popular option, products formulated with macrocyclic lactones (i.e. ivermectin horse wormers) work by blocking nerve transmission in worms, causing paralysis and eventual death. Macrocyclic lactones are generally very potent, and unlike other common horse worming ingredients, can also address external parasites living on the animal’s skin.

Benzimidazoles are another common choice for farmers, and these work by inhibiting essential metabolic processes in the parasite, causing them to slowly die. They are also effective at eradicating parasitic eggs found in the animal’s stomach or faecal matter.

What are the implications of not using horse wormers?

Horse wormers are a non-negotiable tool for owners as they protect the animal against the negative effects of contracting a parasitic infection. If internal parasites like roundworms, tapeworms, and bots are left ignored, the health consequences for the animal can be dire or potentially even life-threatening. Wormers should be used as part of a comprehensive parasite control program for all of your horses, rather than individually, as parasites are identified – this is because parasites can spread easily and rapidly among horses through shared grazing areas, water sources, and grooming equipment. With a deworming strategy in place for all of your livestock, you can avoid any potential outbreaks. 


How do I use horse wormers? 

There are a few common forms of horse wormer, all of which must be administered orally by inserting the product, either directly or via a syringe, into the horse’s mouth. Horse paste has a gel-like consistency and is given to the horse using a syringe placed under the tongue or towards the back of the throat. Liquid horse drench is administered using the same mechanism. Both of these options are recommended to be given to the horse without food, as this decreases the chance of the wormer being spat out. Another commonly used form of horse wormers is pellets, which are designed to look and smell like pony cubes and thus can be given directly to the horse without issue.


Like all drenches, it is important not to overuse horse wormers and to cycle your chosen active ingredients to avoid developing resistance amongst your stock.