Let's Talk...Worms

 Deworming Recommendations
 There is a lot of information out there about the best approach to deworming your horse. My aim is to provide you with information to assist you in determining what works best for you and your horse, while always coordinating with your veterinarian. Deworming protocols are specific to each horse because each horse is a unique individual. Your horse’s immune system, gut bacteria, and living environment play a big role in their ability to maintain a healthy parasite load. Notice there how I said, “Healthy Parasite Load” not “Free of Parasites”. Most horse owners are familiar with the life cycle of worms. However, some horse owners aren’t aware that a particular type of worm can migrate through the bloodstream and nest under the lumbar vertebrae in the back. This of course has the potential to directly affect your horse’s ability to perform. What? Yes. This is called a worm aneurysm, and we will get to that later. There is also the debate of chemical wormers vs. herbal wormers, and I will touch on that also. First, let’s start with a practical approach to evaluating your horse’s worm load.
 
Fecal Egg Counts or FEC, are becoming more widely used. They can be conducted by your vet or there are a few options where you can mail a sample in. I order my FEC tests from SmartPak. They provide everything you need (even a container and spoon) to collect the sample and, the postage is paid. FEC’s are a good starting point, but you also need to be aware that you can’t rely on the results to give you a 100% accurate account of your horse’s current parasite load. The manure sample is a snapshot of what’s going on in your horse’s body and the number of eggs it contains is easily affected by the inflammation present on the day/time of the sample. It should also be noted that the FEC does not account for tapeworms or bots, both worm types that can have serious health consequences. However, I still consider FEC to be a valuable tool to provide us with more information. If you have recently purchased a new horse, or have not conducted a FEC in the past, I recommend you perform 3 tests over a period of 3 months. If possible, collect the samples at the same time each day. This will give you more of an idea of what type of shedder your horse is. Horses are classified as High, Medium, and Low shedders of worm eggs. This information can be helpful in determining the frequency and the protocol to take when developing your deworming protocol. When you are first starting your FEC, I recommend you follow the frequency recommended by you vet based on the shedder classification you horse has been assigned. Your vet will likely recommend a class of chemical wormer to best treat the stages and types of worms present in the FEC. That being said, let’s shift into the chemical vs. herbal wormer discussion.
 
If we must utilize non-holistic practices with our horses, I personally use the risk vs. benefit thought process. Because I have seen some very negative physical effects in horses with bots, tapeworms, and worm aneurysms, I utilize chemical wormers at the smallest amount and frequency possible for my horses. Chemical wormers have been shown in studies to detox from tissues easily and in humans are actually shown to be beneficial in ways other than deworming. I most commonly use Zimectrin Gold (Ivermectin and Praziquantel ) for my horses. My horses are all consistently classified as Low Shedders and my vet advises deworming twice per year for tapeworms and bots. I do not personally recommend anyone use Quest or Quest Plus. I have seen some very adverse reactions to those products. Chemical wormers are still chemicals, and anytime we introduce chemicals into our horse’s bodies, it is a wise thing to provide a detox. A couple easy and safe approaches to this are administering liquid bentonite clay (or powder that is hydrated) at a rate of 1 ounce per day once per day for 4-5 days. Please remember that bentonite clay will not allow the body to absorb anything for up to 2.5 hours after giving it. I recommend not giving it at the same time as other supplements or medications your horse is taking. Another option is to feed one handful of dandelion leaf once per day for 10 days. So does this mean I am opposed to herbal wormers? No. I think herbal wormers can be useful when fed to a horse that has shown a trend to be a Low Shedder. However, I have not seen evidence that they are a solely reliable source of eliminating tapeworms or the large strongyle larva that can migrate to the mesentery artery and cause a worm aneurysm. What’s a worm aneurysm? I’m glad you asked.
 
A worm aneurysm, or Verminous Arteritis(I just noticed this is mentioned on the back of the Zimectrin box!), occurs when the Large Strongyle Larva migrate into the mesentery artery and nest under the L2-L3 vertebrae in the back. The degree of the worm aneurysm is graded 1-4, with 4 being the most severe and the vertebrae becoming fused. Two questions probably came to mind, is this reversible? And, what causes it? The answer to the first question is, it depends. If the worm aneurysm is a Grade 1-2, it is usually resolved with a specialized worming treatment involving a Panacur PowerPak and an Osteopathic session to clear the artery. Unfortunately, Grades 3-4 can only be helped by preventing the larva to do any further damage to the artery, but the vertebrae are usually fused by that point. I have worked with several horses with Grades 3-4 who are able to comfortably be ridden at a lower impact discipline. The cause of worm aneurysms is confirmed to be due to a large parasite load of Large Strongyle, but there also seems to be an element of lifestyle and diet that play a factor. Horses who are continuously under stress, fed an inflammatory diet, and wormed regularly are still at risk. This is a good reminder of how powerful inflammation is in the body. If you suspect your horse may have a worm aneurysm, it is best to consult an Osteopathic Practitioner and your vet.
 
Blessings,
Amy