The one I really wanted to attend was about parasites in sheep and goats. Things change quickly in the war on goat parasites. Down here in the humid South, most dewormer products (anthelmintics) are no longer effective, and the parasites (worms) have become resistant to most, if not all, dewormers. I wanted to learn about the current protocols in deworming.
A few years ago I took a class on the Famacha system, a method to help farmers identify parasite infection in small ruminants. Only the animals that require it are then dewormed rather than the whole herd being dewormed on a regular basis. The Famacha system addresses mainly the barberpole worm (Haemonchus contortus), but there are many other parasites that kill goats and sheep.
Our speaker was Dr. Barry Whitworth from Oklahoma State University, who has worked with goats for many years. He began with an overview of the different worms that cause problems in goats, with the major culprits being Haemonchus contortus, Teladorsagia (Ostertagia) circumcincta, and Trichostrongylus axei; these three are referred to as "HOT". It's estimated that 85% of goat ailments are caused by internal parasites.
This is written from notes I took during the session, so I hope they make sense.
While parasites in general are resistant to most of the chemical dewormers on the market, resistance to an individual dewormer will depend on which products you have used in the past on your own goats on your own property.
Worms have become resistant to chemical dewormers due to the following practices: frequent deworming, underdosing, injecting dewormers, pouring on dewormers, using "persistent activity" dewormers, putting dewormer directly in the animal's mouth, dosing on a full stomach, deworming when infection levels are low (in the animal and on the pasture), putting newly-treated animals on clean pasture, treating all animals in the herd, improper use and storage of dewormers.
Dr. Whitworth said that all of us are probably guilty of some of these practices, admitting that he himself has done all of these. Here's what I will be changing on my homestead:
- Dewormer should be administered to the back of the throat using a drenching gun - I've been guilty of just squirting it into the goat's mouth.Choose the least thrifty animal in your herd to test for fecal egg counts. Worm strategically - only the animals that need to be wormed - using a cocktail (combination) of anthelmintics. Run fecal egg counts before treating and again 7-14 days later for comparison, to be sure your deworming products and methods are effective. Cull the animals in your herd that constantly have a high fecal egg count.
- Animals should be dewormed on an empty stomach. Fast the goats overnight and give the dewormer on an empty stomach. Administer a second dose 2-4 hours later.
- After deworming, animals should be put on a feedlot for 2-3 days, then moved to a clean pasture.
- I will be more careful about storing dewormers. I've never been careless, but I'll be paying more attention to be sure I'm storing at optimum conditions: a controlled room temperature of 59-86°F.
Maintenance practices are very important, and Dr. Whitworth stressed that maintenance will become more and more important in the future since resistance to dewormers is so high. For instance, don't feed your sheep and goats on the ground, rotate your pastures, move animals to a dry lot for two days after deworming.
Purchasing a goat from someone else will bring a new crop of parasites to your property, along with those parasites' own dewormer resistance. When you bring in a new animal always quarantine it so that it won't drop its parasites on your pastures to inhabit your current goats.
Goats are browsers rather than grazers; they'd rather eat brush and trees than grass. Having browse for your goats to eat is important. Worms will travel about 2-3" up the grass blades, so you want your forage to be taller than that. Parasites can slide around more easily on wet plants, whether it's wet from rain or morning dew. Waiting until the dew dries in the morning before letting your herd out on pasture is also helpful.
He also recommended the use of sericea lespedeza, either growing in your pasture or as hay. The tannins in the plant help to control the barberpole worm. You can find more information about using sericea to control parasites here.
There is no research at the university level on herbal dewormers. According to Dr. Whitworth, herbal preparations are best used with a program of chemical dewormers; the herbal formulas boost the goat's immune system, which better enables them to fight off a parasite infestation. I use an herbal dewormer from Hoegger Goat Supply weekly, but I do use a chemical product if it's needed. During the summer my goats have such beautiful slick coats and are in such good condition from the herbal product.