Desert horses and Sand Issues
Anyone that has ever lived in the southwest knows that there is no shortage of sand. Sand and dust manage to find its way into and onto everything here including inside of our wonderful equines. While it is annoying for us to deal with on our cars, furniture, and every other surface, this sand can be fatal for our equines. We are briefly going to take a walk through the dust and discuss how this type of dirt impacts our horses.
First, we must talk about where the sand comes from. Well, pretty much every inch of soil here in the desert southwest is covered with it. You can’t look in any direction and not see more and more sand. But we have so much that it isn’t just covering the ground. When the wind blows, it picks up the sand and carries some of it in the air. This results in sand being present not only on the ground where an equine may graze or eat but even small amounts are even in the hay. Some can even end up in the water. It’s literally everywhere.
Sand being everywhere is part of why it is such a problem for our equine population. One of the hardest things for owners to grasp is that their equine is constantly ingesting some amount of sand. Yes, every equine is ingesting sand that lives in this region. So, this begs the question how does one stop this? Well, the only 100% guaranteed way would be to move, which most likely is not an option. Since not going to move, we have to look at ways to minimize ingestion. To minimize ingestion, we are going to have to look at the factors related to ingestion. The simplest method to understand is they pick up sand while they eat off the ground. Sounds simple right?
Well not quite. Horses, donkeys and mules have incredible ability to sort with their lips. A healthy, young equine with normal head anatomy (dentation and soft tissues) has the ability to sort out a grain of rice from a bucket of mixed grain. If you don’t believe that, try feeding one a pill with grain. What we are getting at is they are very proficient at reducing their sand ingestion when they are young with good dental health and less so as they age. Now, each particle of sand is smaller than a grain of rice so they still can’t sort it all out and will ingest some.
Okay, I won’t feed them on the ground and that will eliminate the sand. It’s not that easy.
These animals are meant to be grazers, they evolved to eat with their heads down. A lot of them will toss the hay all over the place and out of any container you put it in. Most turn to mats to help with the hay all over ground, but what is the mats covered with in just a couple hours… sand. These are methods to help reduce ingestion, but feed troughs and mats are reductive aids not solutions.
An equid should be eating 18-20hours per day, in captivity most are lucky to eat for 4 hours a day. What do they do the other 20 hours of the day. Well, most wander around a dry lot looking for every last crumb of food they can find. As they search out these last crumbs, their prehension and sorting ability is reduced. Every crumb comes with more and more sand. Our ground being nothing but sand really makes it nearly impossible to prevent some level ingestion. Oh, but wait, that sand is in the feed, water, and air as well. Those that feed in troughs, and such have seen the amount of dirt that accumulates in bottom, all of that and more was in the bale. It’s not the hay producers’ fault as they are working with the same ground as we have if locally grown. Some hay of course has more than others. And to lesser degrees we end up with some exposure from the air and water. Dust devils like to roll through paddocks. And with the wind there is almost always a skim layer across water sources. These last two likely the smallest of factors for where the sand is coming from. But here in the desert, sand is everywhere, and our equines are constantly ingesting some.
How does sand accumulation impact our equines? Horses, donkeys, and mules have a poorly designed gastrointestinal system. It has several problematic areas. When it comes to the sand, the large colon and cecum are the areas that are most impacted. The cecum is a functional appendix for these species and is a comma shaped blind end sack. With the entrance and exit so close to each other the sand can migrate to the end away from these and just accumulate or if it does pass through it’ll often build up and sit in the lower section of the large colon. Accumulations can vary from a few pounds to well over 80 pounds. Larger accumulations often decrease the surface area for nutrient and fluid absorption resulting in animals that are “hard keepers” and have frequent bouts of diarrhea. Diarrhea is often the first sign that most owners notice. Some may notice a dull hair coat, lethargy, discomfort at certain gaits or just difficulty to maintain. Now sand is not the only possible cause for this list of symptoms but in this region, it is high on list.
If one is fortunate, it is caught when only these mild signs are present. Given long enough (can be as short as 2 weeks), sand can accumulate to the point that it is irritating the intestinal tract or even causing blockages that stop progression of ingestion leading to typical colic signs. The most severe cases can even lead to bowel displacements following rolling as the sand is heavy and tries to always remain towards the ground no matter the orientation of the horse. Sand is not something that should be ignored until it is a problem.
An ounce of prevention is worth a pound of cure here. Once more there is no 100% way in this region to prevent some ingestion of sand. Our goals should be to reduce the amount ingested and to encourage what has been ingested to be passed on through. It’s illogical to put filtering masks on one so the air side of the equation needs to be aimed at just keeping the area as low dust as possible. Water your arenas when work, don’t ride into dust devil, don’t use leaf blower directly towards them, things to just keep the dust levels in air down. The water is similar, some will benefit from using a filter as some water sources have high sand counts. The simple in line hose filters for an RV will help. Even if you don’t frequently clean your water troughs if seem dust film, overflow it for moment to let that film flow off. What about the ground and feed ingestion, well again no way will 100% eliminate sand ingestion. It’s helpful to keep the horse in good dental health by having a good relationship with your veterinarian to properly schedule and perform dental work as needed. This helps with prehension by the animal and its natural ability to sort out the sand. You should try to feed as low of dirt content hay as possible. Dirt content can be reduced by breaking up bales and flakes, soaking, or even steaming the hay. If you are going to feed in a trough, the bottom should be cleaned out frequently or have an inaccessible bottom that allows the dirt to fall out of reach. Because of respiratory concerns feed troughs should never be deeper than an animal’s eye level. As mentioned above, mats are helpful, but sand will accumulate on these. It would be necessary to clean them off at basically every feeding for them to have full benefit.
Our preferred method of prevention is to be mindful of the nature of the animal. By this we mean that we target them being grazers and eat for extended periods of time. An animal eating for 12 plus hours a day versus 4 hours a day has 8 hours less time to digest sand. This increased time eating also normally translates to more roughage ingested. A good rule of thumb is more roughage in, more sand out. Fiber helps to move sand on through the digestive tract. If there is food available, the animal is also less likely to be hunting for every last crumb which reduces the ingestion of sand. Now many of our animals cannot be on free choice hay. Slow feed systems work well to help extend eating times. Smaller more frequent portions can create similar effects. We encourage all our clients to feed a diet that is at minimum 50% grass hay based. From our own experience, we see almost no sand issues in our equids maintained this way. Other options include the use of fiber sources such as psyllium, but we have seen a number of sand colic cases still on the 7 days once a month regimen. It is cheaper to try and prevent than it will be to treat.
Prevention has failed, my horse has sand.
Treatment options are based off all the above methods to reduce ingestion and to encourage passage of the sand. Severe cases may need surgery to have the sand flushed out. This procedure can cost north of ten grand here in Arizona. Some cases medical management with pain control, fluids (oral and intravenous), and change in lifestyle will improve and may eventually resolve the issue. The average sand case that we diagnose will be on a treatment plan for at least 3 months with most are on it for longer. We diagnose and monitor sand through 3 main ways.
The first and simplest is a manure float test which can be done at home by you. Take a handful of fresh manure and put it in a Ziplock bag, add water and hang bag from one corner. Sand will accumulate in the lowest hanging corner. This requires that the animal is actively able to pass any sand through, which may not be the case with every bowel movement.
The second commonly employed method by your veterinarian is auscultation. Abdominal auscultation for gut sounds can also be useful in the diagnosis of sand issues. Movement of sand with the movement of the bowel creates a sound similar to waves along a shore. The animal is often examined for this sound, both during emergencies and routine physical examinations. Less limitations exist for diagnosis to the trained auscultator as active passage is not required.
The final method is via radiographs. Portable radiograph systems do not generate enough power to properly image an equine abdomen, this is not a field diagnostic test. This requires a stationary generator hardwired into electrical system.
The complexity of cases, the severity by time colic symptoms present and the lack of effective treatment options result in sand colic episodes having a guarded prognosis. These are often difficult to manage and extremely stressful for the client and the veterinarian. We strongly encourage trying to be as preventative as possible. Work with your veterinarian to try and diagnose issues early and treat them promptly. If you live in the southwest desert, you are never going to be able to avoid sand in your equids. But there are ways to reduce ingestion and encourage the passage of sand which reduce the risk of developing colic from SAND.
This writeup is for educational purposes and does not constitute veterinary medical advice. You should always consult with your veterinarian should you have concerns about your specific management plans. Your veterinarian is your best resource for guiding decision making for the health and well-being of your animals.
Dr. J Alltop, DVM