There are numerous types and brands of wormers available and it can appear a bit daunting when trying to determine which type of wormer to use and when, in order to keep your prized purebred Spanish horse or Andalusian horse free of the nasty little critters.
To make matters more complicated, the average PRE stud, breeder or owner will often have untreated Andalusian purebred Spanish horses and PREs arriving from Spain, foals and young stock, mares in foal, some horses out grazing much of the year and some stallions largely stabled.
The Basic Principles of Worming Horses
There are several or more types of ‘worm’ with different breeding and life cycles, including lungworm, bots, roundworm, redworm, tapeworm, pinworm and encysted redworm (or cyathasomes). Each type of wormer contains a different active ingredient that treats for different types of worm infestation and some are more or less effective than others, depending upon resistance.
Different Wormers, Different Worms
We can’t stress enough the importance of undertaking regular worm egg counts (faecal egg count), normally about eight weeks after the last worm treatment or before the next treatment. However they do have limitations, as they only detect worms that lay eggs, so tapeworm and pinworm infestations will not be identified and they also do not detect immature and encysted stages of small redworm. A faecal egg count will nonetheless help you to decide whether you firstly need to worm your horse at all, and if so, which type of wormer is most appropriate.
The three main types of wormer you will find are Panacur, Equest and Eqvalan, each using a different active ingredient to treat bots, adult and immature roundworm, redworm and lungworm. You should not rely exclusively on Panacur, or other wormers belonging to the bendazole group, as there is widespread resistance to these wormers.
Equest Pramox and Equimax are the complimentary versions of Equest and Eqvalan, by treating not just the above parasites, but also tapeworm and are used periodically within a worming programme to treat tapeworm.
Lastly Panacur Guard 5-Day is recommended as part of a worming programme as it is effective in controlling encysted cyathasomes (immature small strongyles in the wall of the large intestine).
Equest should not be used in foals under the age of 4 months, or initially in very thin ponies or equines with very high worm burdens. A Panacur Guard 5 day course should be used when treating debilitated ponies or those with a heavy worm burden and prior to any other wormer or beginning a worming programme.
An Easy To Follow Worming Programme
If you’d rather skip the lesson in biology and pharmaceuticals and go straight to the practical solution to worming your beloved Spanish horse, then below is a simple worming programme/calendar which you can follow, safe in the knowledge that it has been compiled by a vet who does understand the finer details.
Worming is suggested every 8 weeks for Eqvalan or at least every 12 weeks with Equest – see table below. Equimax or Equest Pramox should be given at least every 12 months to remove any tapeworm. This regime does not remove all worms but aims to reduce the worm egg count to well below 500 eggs per gram (epg) and with good pasture management, to reduce horse’s worm burden to very low levels over a period of time.
There is a two-year alternating programme which, by alternating the type of wormers used, minimises resistance amongst worm populations. There is a suggested worming plan for new (healthy adult) horses that arrive on your yard, and similarly for those that you suspect are carrying a heavy worm burden or are young, old or in poor condition/health. You need to be particularly careful when foals and young stock, as age and weight determine which type of wormer is safe to use, and always be careful when determining dosage.
If in doubt, consult your vet!