Current research confirms that parasite resistance to anthelmintics is a growing problem worldwide. Rotational de-worming programs (every 6 to 8 weeks) are no longer effective because they contribute to the parasite resistance. The most logical way to prevent this from happening is to minimize the frequency of paste de-worming or daily de-wormers. By reducing the selection pressure placed upon the parasites the resistance problem will be reduced. Proper rotation of the different drug classes is important because some parasites survive the treatment with certain anthelmintics and then reproduce a new generation of drug resistant parasites known as the “super worms”. De-worming is no longer a simple do it yourself procedure, but a complex multifaceted issue with serious health consequences for your equine companions.

To fight the resistance CVS suggests:
CVS stresses the importance of having fecal egg counts done 2 - 4 times per year.
Fecal egg counts (FEC) measure the concentration of EPG (eggs per gram) of your horses manure. Dr. Winter is then able to interpret and diagnose the drug resistance issues in order to determine which de-wormers should be used as well as the frequency of treatment for each individual horse. (FEC) should be done 10 to 14 days after de-worming to establish the effectiveness of the product used. A second fecal should be done at the egg reappearance period (ERP).The (ERP) is a predictable interval where the fecal egg count remains low after an effective de-worming agent is administered. The time frame varies according to the product used.

The second fecal helps to determine, which horse has a high parasite load and/or if your paddock or pasture has a parasite problem with re-infestation. By identifying this problem, CVS can provide you with a targeted treatment for each individual horse and/or environment. Dr. Winter will evaluate your situation, estimate your horse’s weight, and customize an individualized de-worming program that best suits the needs of your horse(s) and your facility. For optimal impact, he will advise you to administer an effective dose of the right anthelmintics at the appropriate time of year.

CVS encourages you to protect the environment of your horse to prevent them from getting infected with the parasites in the first place.

	Remove feces from the stalls daily and paddocks twice weekly. By doing so, the infective stage of eggs and larvae is decreased and the life cycle is interrupted.
	Remove bot eggs from the hair coat twice weekly (A flea comb works well)
	Rotate the paddocks or pastures and don’t over graze or overcrowd them
	Rotate livestock species in pastures when possible
	Compost the manure properly if you intend to spread it on your pasture.
	Feed horses away from contaminated areas using feeders for hay & grain
	Harrow cautiously (hot summer days) & leave pastures vacant for 2 weeks
	Quarantine and de-worm all new horses before turning them out with your herd. Use a larvicidal dose of fenbendazole, followed by Ivermectin or Moxidectin. In 10 to 14 days post treatment have a fecal egg count done to test the wormers efficacy.

Click here to print/view the Paste De-wormer Chart.

Click here  for Parasitic Control and Prevention.