Today most horse owners have a deworming plan that they follow. There are an increasing number of wormers on the market which has complicated the purchase decision for most producers.

For optimal impact, you need to use the right dewormers, at the correct dose at the right time. If you have been using the same dewormer through the season, you may want to have a visit with your veterinarian to discuss a worming program.

As with all parasitic control, rotation between products with different chemical classes will offer you the greatest control between seasons. You need to be certain that you are rotating between active ingredients rather than just brand names.

The first class of products are the avermectins and milbemycins and they have a broad range of activity. In this class are the Ivermectin type products that are effective for adult worm control with the exception of tapeworms. It is also effective for some larvae but does not kill the small strongyle larvae. Examples of this product would be Bimectin, Equimax, or Eqvalen as some examples. This class also includes the moxidectin which is similar to ivermectin but does control the small strongyle larvae and such a product would be Quest Plus or Quest Gel.

The second class of parasitic control is known as Benzimidazoles and they include compounds that end in “-endazole” and are effective against a number of adult parasites. In this class, fenbendazole kills large strongyles, pinworms, lungworms and ascarids; oxibendazole is effective against large strongyles, pinworms, roundworms and threadworms. These are the active agents of products such as Anthelcide EQ, Panacur and Safe-Guard Equi-Bits and Safe-Guard Paste and are considered an excellent summer wormer.

The third class of parasitic control are products that contain pyrantel salts. In this class, pyrantel pamoate controls large strongyles, pinworms and roundworms and, at double-dosing rates, kills tapeworms and an example of this would be Exodus Double Dose. This product would be a great spring and summer rotational product.

As you can see, it is important to rotate the worming products depending on the season and the expected parasite load. Contact your local vet for a worming protocol or stop by MHFC Livestock Supply to review your worming program.