One of the biggest news items in equine medicine is the resistance of intestinal parasites to many of the common dewormers we have today. Antibiotic drug resistance has developed to bacteria in human and animal medicine, and drug resistance has also developed to internal parasites in animal medicine. If you have livestock of any kind, this resistance should be a concern to you.

Resistance of parasites is so severe in sheep and goats that many areas of the country are unable to raise these animals. Resistance is also developing in cattle and there is already a lot of resistance to small strongyles in horses. Many of the commonly used dewormers sold in feed stores including Safeguard and Strongid have been shown to be ineffective in many cases and we have talked about this on Texas Vet News before. However, I wanted to mention it again as I still see new clients who are deworming their horses with ineffective products, and are still doing so every 8 weeks. If we do not change the old practices of deworming all horses every 8 weeks, we will soon not have any dewormers that are effective and this will be a real problem for the horses.

The recommendation at this time for adult horses is to use an ivermectin compound and Quest at least twice a year and once yearly the dewormer should contain Praziquantel for tapeworms. Some horses will need to be dewormed with these products 3 to 4 times per year and this should be determined by having your veterinarian check the parasite count of each of your horses, at least initially. Although there is some added expense initially in checking the fecal analysis, in the long run this new program will actually save you money and will help decrease parasite resistance on your horse farm.