Tips on Parasite Control for your Horse Guest Author: Gina DePinto
Farnam Companies, Inc.

It's a fact that all horses have internal parasites. If leftunchecked, bots and worms can rob a horse of necessary blood, nutrients and energy. If left untreated, a horse suffering with parasites can experience permanent damage, chronic digestive problems and weakened athletic potential.

The good news is parasite damage is easily preventable. There are many products on the market to provide you with options for a safe and effective deworming program. Choose a program that fits your situation and stick with it.

There are currently three classes of dewormers available that are effective to some degree in controlling horse parasites: macrocyclic lactones, pyrimidines and benzimidazoles. Each class is like a family, consisting of chemical compounds that share common structures and common molecules. However, you should note that effectiveness within chemical classes varies.

'Advances in science and sanitation have helped horse owners control parasite infestation. Industry experts suggest these general rules for keeping the parasites under control.

MAKE SURE YOU'RE GETTING BROAD-SPECTRUM CONTROL
Look carefully at the parasite species and stages each product says it will control. Some dewormers target only a half-dozen internal parasites, while others are effective against a much broader range.

What's not on the label can be important, too. If a dewormer does not mention "bots," for example, there's a reason. Some deworming products don't have a label claim for controlling bots. For a product to control bots, it must say "boticide."

Paste dewormers are popular among horse owners who maintain a regular schedule of oral administration with a pre-measured syringe containing a broad-spectrum dewormer. Each syringe has a full dose in either a paste or a gel compound.

BEWARE OF AGE RESTRICTIONS
Young foals are particularly at risk from internal parasites and the consequences can be grave. Foals can be treated at seven days of age to help prevent "foal-heat diarrhea," which can be associated with Strongyloides westeri (intestinal threadworms).

Another example is ascarids, or roundworms, which can cause serious problems for foals.

Not all dewormers, however, are labeled for use on young foals. Scan the fine print for age restrictions before selecting a deworming product. Products that are labeled as safe for use on foals without age restrictions can help protect foals during this critical early period.

OTHER CONTROL TIPS

• Whatever deworming method you choose, use it diligently. If you choose rotational deworming, be sure to follow label directions and administer the dewormer every six to eight weeks, or as indicated by laboratory exam of your horse's manure. If you choose to deworm your horse with a broad-spectrum dewormer, make sure the product of choice truly is broad-spectrum. Administer it every six to eight weeks or as indicated by laboratory exam of your horse's manure (and, again, don't forget about bots).
  
  Daily dewormers, such as Continuex™ (pyrantel tartrate), provide constant control of key parasites before they can cause damage in the horse. Pyrantel tartrate, the active ingredient in Continuex, is effective against the parasites that harm your horse most: small and large strongyles, roundworms and pinworms. If you choose a daily dewormer, be sure to add an effective broad spectrum larvicide and boticide at strategic times - at least twice per year - to kill bots and other species daily dewormers don't control. One of the leading boticides on the markets is ZIMECTERIN® (ivermectin).
  
  Don't blindly accept advertising claims that advocate deworming less often, no matter what the product is, unless there's proof that all the parasites that threaten your horse are effectively killed on that less-stringent schedule.
  
  Research has shown that parasites, specifically small strongyles, can develop strains resistant to dewormers like benzimidazoles and pyrantel pamoates. The drugs lose their effectiveness when this happens. Your veterinarian may recommend rotation between an ivermectin product, such as ROTECTIN® 1, and a pyrantel pamoate product, such as ROTECTIN® 2. These products are in two distinctly different chemical classes. As an added bonus, ivermectin contains a boticide and has maintained its status as a resistance-free dewormer.
• Do not spread fresh, uncomposted manure on grazing pastures. Compost manure for at least a year, turning it frequently to produce heat needed to kill the internal parasite larvae. Recent studies have shown that shredded newspaper bedding reaches higher temperatures when composted than traditional straw or wood shavings, killing more larvae.
• Remove manure from your horse's stall daily. Some horse owners and veterinarians recommend mowing and chain harrowing to help expose larvae to the sun and wind, which can dry out the larvae and kill some larvae. This method works better in hot, dry areas. Before you harrow, contact your equine agricultural specialist and/or local university to determine if this method is an effective way to kill parasite larvae in your area.
• Don't overcrowd pastures. Experts advise a minimum of one acre per horse, more if pastures are thin or soil is poor.
  · Rotate pastures between cattle, sheep and horses, since parasites are different between species.
• Wash water buckets regularly and replace water daily.
• Use repellents and insecticides as recommended.

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