Dr. Brian Eitelman, DVM, CJF, and Aggie Vet and Farrier Services provide veterinarian and farrier services in Parker, CO, Elizabeth, CO, Franktown, CO, Castle Rock, CO, Sedalia, CO and Larkspur, CO. To learn more, please visit us at www.vetandfarrier.com
In this video, Dr. Brian discusses common questions and issues with parasite management in horses.
-The issue is more about parasite management than parasite elimination. This video is about some of the key points and strategies in the management of parasites here in Colorado.
- Twice yearly deworming should be more than sufficient (three times per year at most)
- Great times are right before primary grazing season starts (late spring) and after it ends (early fall)
-Here’s why: deworming before grazing season limits shedding of eggs onto pasture and then after grazing season allows you to address the parasites they have inevitably picked up while grazing.
- The two most reliable products are Ivermectin or (Moxidectin) and Pyrantel
- Every 18 months to 2 years, it is not a bad idea to use a product with Praziquantel to address tapeworms.
**TAKE HOME MESSAGE**
Good husbandry . . . good manure management . . . and good nutrition . . . are far more critical to long-term effective parasite control than any deworming product!!!
So how do horses get parasites??
-Primary spread is fecal - oral
-Internal parasites pass eggs out of the host animal in its manure. Then while outside the host, the eggs mature to the stage in which they can actually infect another animal, and hang out and wait to be eaten and start the cycle again.
- Hot, dry, sunny conditions make the eggs use their reserve capacity faster and die off faster.
- The wetter the pasture is or the more shaded the fecal balls are, the longer the eggs survive
So why is manure management important??
-Grazing through manure is the key step for picking up new parasites.
- Parasite eggs can become infective in as little as 7-10 days and stay infective for 6 months or longer depending on condition. If an egg is that hasn’t matured to that infective stage is ingested, it simply passes on through and continues on with its life cycle.
- Regular and thorough manure removal (at least once weekly) is key! If you can get the manure out and away, the eggs never have a chance to infect the next horse.
- Use feeder to keep animals from standing in hay.
- Avoid overstocking as more animals = more manure = more exposure
- Make sure of sufficient feed in sufficient space for ALL animals
So often, the animals lower in the pecking order are forced to graze through contaminated feed or the dirtiest parts of the pasture.
Why is good nutrition so important?
- The immune system is one of the first systems sacrificed by the body when poor nutrition is present. Domesticated animals have developed some inherent resistance/tolerance to parasites which is again why we talk about parasite management rather than elimination. However, inevitably the immune system is compromised and every animal is susceptible. Good nutrition keeps the immune system robust and better able to resist the pressure of parasite exposure.
- From a practical standpoint, a good nutritional plane indicates a large supply of good forage. While this sounds obvious, there are several important behavioral observations worth noting:
- Plenty of good forage means that animals can be pickier about what they eat, meaning that they are less likely to graze through manure-contaminated feed.
- Lack of good or sufficient forage means that an animal is forced to graze though poor or contaminated feed/pasture. Very often, the animals lower in pecking order have much higher parasite loads because of these points = poor hay = poor nutrition plane = poor immune system = poor energy/sick/”poor doer” = poor hay and cycle continues and puts healthier animals at further risk.
So what about Fecal Egg Counts?
- A tool for deciding which animals need deworming and measuring for resistance to dewormers and in theory, they should be great for these purposes. But because of inconsistent results, tend to give a false sense of security. If I’m going to do a fecal egg count with a reliable lab, the main thing I’m looking for is the count before administration of dewormer, and the count afterwards and I want a significant drop in count. Lack of drop in egg count after deworming is a good indicator of resistance. A zero egg count to me is more an indication of need to retest and check test protocol rather than a parasite-free animal.
Which dewormer should I use for my horse? Which wormer should I use for my horse? How often should I deworm my horse? How often should I worm my horse? How often does my horse need to be dewormed? How often does my horse need to be wormed? When to deworm a horse? When to worm a horse? When to deworm my horse? When to worm a horse?