Worming less may benefit your horse
Drugs are not necessarily the right choice to ensure your horses’ health
EXPERTS have issued advice on treating worm resistance, which can prove fatal. The issue is growing (see left) and owners must take responsibility for helping to combat it, which will benefit individual animals, as well as the species as a whole.
British Equine Veterinary Association council member David Rendle told H&H that “fundamentally, owners need to use less wormers” and work with vets to minimise need for drugs.
“Most doses of wormer are administered unnecessarily. Misguided ‘interval-dosing’ was recommended in the 1960s, but has led to resistance. Since the 1990s, vets have been aware that more sustainable methods of worm control are required and have been recommending worming on the basis of need.
“But 20 years on many people still interval-dose and resistance is increasing. Resistance is likely to be irreversible and, once it’s present on a property, the owners have a real problem. There are no new horse wormers in development,” the vet revealed.
Mr Rendle said every time a wormer is given, susceptible parasites die but resistant ones survive, breed and pass on their resistance.
He said owners must accept it is normal, possibly beneficial, for horses to have some worms, and that treatment is only needed to prevent disease, not to eliminate parasites altogether.
It is also important owners give an appropriate quantity of wormer, as many underestimate horses’ weight and under-dose, allowing partially resistant worms to survive and spread their genes.
Worming plans should be discussed with a vet, he said, adding: “Most adult horses that are well managed should need no more than one or two doses per year. If management is good, droppings collected from pasture regularly and a blood or saliva test performed for tapeworm annually, adult horses with good immunity may not need to be wormed at all.”
Wendy Talbot, of animal health company Zoetis, told H&H the main principle of worming is to limit the development of high parasite burdens internally and, “crucially”, limit worms on grazing so they do not reach unsafe levels.
“It’s still important to worm when required, but a treatment plan should be developed for each horse,” Dr Talbot added.