Join Date: Jul 2010
Location: East Central Illinois
Along with your new horse, you need a new horse Vet. Take your Vet's advice. It used to be that everyone rotated wormers. I still do that bc some parasites resist certain worming chemicals. Now, a lot of Vet's take a fecal sample to determine if your horse is a high or low parasite carrier and then suggests wormers and a rotation cycle.
My advice is to buy a tube of Zymectrin and administer when your horse gets home bc it's just like giving a tetanus antitoxin shot after an injury, just to be sure. Ivermectrin has been coming to the market in cheap wormers that are largely ineffective. You'll pay $7--up for a decent tube (up to 1,200 lbs). Ivermectrin was the 1980's wonder drug for horses. It is now used for other animals and humans, and the tube is paste with 1.87% (0.0187) of the drug in the paste.
In the Fall you will want to use Quest, which contains praziquantel to kill tapeworms. Your Vet will also give yearly shots which includes Tetanus (Toxoid), and specific to your area of the country, which may include Rhino, Eastern/Western Sleeping Sickness, Potomac Fever, and my Vet gave Rabies last year.
Read the instructions for worming. Pryrantal Paomate, Fenbendazole, Oxibendazole (I think some wormers still use this drug), will tell you when to re-worm. Most cover for 2 months, Ivermectrin works for 3 months, Praziquantel (developed here in Champaign-Urbana at the University of Illinois!) covers for 4 months.
Your Vet's input is SOOOOO important. Sometimes you will need to worm all 12 months, maybe your Vet will suggest not bothering with the winter months, but housing and worm egg access can aggravate your horse's parasite load, which is never zero.
Your Vet can also tell you if feeding daily worming pellets is worth the cost, too.