As a professional concerned with your horse's welfare, it is important for me to ensure you are on an efficient worming program. Worms are an occupational hazard in a horse's life and their control is of paramount importance-your horse's health depends on it.

Two excellent wormers have been taken off the market – the Strongid daily wormer and Droncid for tapes – therefore we have had to change our recommendations.

Recently Tapeworms have been recognized as a major cause of spasmodic colic and I have personally seen associated deaths and recognized tapeworm infection in all age groups!

Tapeworms found in manure 1 day post worming

Studies and experience have shown that certain wormers (benzimidazoles) are no longer effective because of developed resistance in the small strongyle worm population. Other wormers have narrow toxicity margins that can endanger your horse's health. Our policy is to recommend only safe (for your horse and the environment) and effective wormers. The following table shows our recent choices:

Wormer	Characteristics	Safety if overdosed	Worming frequency	Relative cost
Pyrantel Pamoate (drug name) Strongid-T- bulk liquid Strongid P-paste Exodus paste-single or double dose	Available as a bulk liquid to be drenched/tubed or put in feed. Also available as single or double dose paste for tapes	Extremely safe used at 2-3x normal dose for tapeworms	Every month necessary (only gets adults). Double dose annually for tapes or more frequently if recognized on farm	1/2 of eqvalen (normal dose)
Ivermectin Eqvalan	Available as a bulk liquid to be drenched/tubed or put in the feed as a paste	Moderately safe	Every 6 weeks
Moxidectin Quest	Available as a paste gel	Twice as concentrated as Ivermectin so 1/2 the safety margin. Not reccomended for young stock or emaciated horses	Every 3 Months. Has a residual effect and gets many encysted strongyles	1/3 more than Eqvalen
Moxidectin & Praziquantle Quest Plus	Paste - gel	Same precautions as for Quest	Twice a year. Same efficacy as Quest plus it kills Tapes	2/3 more than Eqvalen but lasts twice as long & kills tapes

All foals should be wormed monthly starting at 1 month of age! I recommend monthly dosing with Eqvalen liquid at 1 cc for every month of age (for your average sized horse – not a mini!). Giving a double dose of Pyrantel (Strongid –T) on alternate months makes sense to control adult roundworms & tapeworms!

Monthly worming prevents a great percentage of colic and respiratory diseases. Foals benefit tremendously in terms of growth, feed efficiency and general appearance by controlling strongyles and ascarids. Twice the normal dose of Strongid-T is safe and controls tapeworms.

Moxidectin (Quest) can replace Eqvalen after 4 months but I prefer to wait until 10 months. It is stored in fat depots which are scarce in younger foals and the formulation is twice as strong which can result in dosing miscalculations.

At the yearling stage intermittent (every 3 months) moxidectin (Quest) treatments are considered ideal since the latter is needed to kill off bots in the summer/fall season. Otherwise, every 6 weeks is needed if using Ivermectin and every month is necessary if using Strongid-T liquid.

In the adult horse Quest is currently the best overall wormer (no known resistance & kills a wide variety of worms at all stages of their life cycle including most encysted larvae.) The gel formulation melts in the horse's mouth (not in your hands) and is easily administered.

Remember that tapeworms need to be addressed at least annually.Quest Plus is the simplest solution. Pyrantel can be used at 2-3x the labeled dose to kill tapes. Pyrantel does come as a double dose paste now called Exodus.

For my own horses (adults) I find the simplest & most effective worming program includes worming 4X per year, alternating between Quest & Quest Plus.