I just finished reading the May 2009 issue of The Horse magazine. I was very interested in the article on worms in horses. This article focused on the resistance worms have developed to chemical dewormers. It seems that the conventional wisdom is coming to the same conclusions that many of us holistic types have been suggesting for years.

Regular schedules of chemical deworming for all horses in all situations is not the way to go. This kind of blanket deworming program is partly responsible for the resistance we see in horse worms. Because the worms have been repeatedly exposed to a narrow range of chemicals they have adapted. Even products like eqvalan are showing return of worms within a few weeks in some parts of the country. The really scary thing is there are no new chemicals in the pipeline to replace the products we have now.

Alternative deworming programs on the other hand do not depend solely on chemicals but focus more on building the digestive system of horses so the parasites do not get a chance to infect the horse. By having normal gut motility and a healthy gut lining many worms pass right through the horse without having the opportunity to attach themselves or stay long enough to reproduce. The few worms that may remain stimulate natural immunity without causing significant damage to the horse. I have used a full spectrum probiotic on the full moon each month to clean and condition the digestive systems of my horses. I give 15 of these probiotic capsules to a 1000 pound horse. Some people repeat this process on the new moon as well. This program has served me and many of my clients well for many years but it is not a guarantee so it is still important to evaluate your horse’s condition regularly.

Pasture and manure management is another tool against worms in a natural program. Manure cleanup and composting plus rotating pastures between different species are methods which have proven very effective. Manure should always be well composted before it is put back on pastures where horses are grazing. The heat produced by proper composting will kill the eggs and larvae of horse worms. Harrowing to spread manure out in a pasture can be good if it is done in the hottest part of the summer and horses are kept off the pasture for several days to weeks to make sure the larvae have been killed.

One thing that new research is confirming is that not all horses get or shed worms at the same rate. This is yet another reason not to do blanket deworming programs. Some horses are considered worm shedders and these horses will need a more intense management program than normal horses. Regular fecal flotation tests can help you pick out the shedders in a herd and your chemical deworming program can be focused on these horses while the rest of the herd is managed with natural methods.

I have noticed that some people have become a bit complacent about worms in horses and seem to think that their horses could not have worms because they have them on regular deworming programs. I have been teaching people for years that this is not the answer and it is nice to see the confirmation coming from mainstream medicine now as well. Madalyn