THE FRIESIAN Megaesophagus

in Friesian Foals

We are so grateful for all we have learned while caring for Martin. 44 JULY/AUGUST 2021

By Angie dePuydt is the involuntary constriction and relaxation of the esophageal Education & Research Liaison, Fenway muscles, which create wave-like movements that push food in Foundation for Friesian Horses the towards the . Many reported cases of acquired megaesophagus in Friesian horses involve mature or senior horses in their mid-teens that present with “choke” induced by an esophageal obstruction related to forage or feed. However, megaesophagus can be inherited or congenital (present at birth) and does occur in foals and very young horses. ix months ago, the members of the Fenway Foundation’s Board of Directors sat in the kitchen (difficulty swallowing) is sometimes observed in at Fenway Farms dumbfounded. We were on a call neonatal foals (less than one month old) and often resolves with Ids Helinga, Executive Director of the KFPS, spontaneously as the foal’s swallowing reflexes improve. discussing the structure and approach to a new However, nursing foals with megaesophagus may show early Sgenetic research project for megaesophagus in Friesian horses. signs of the disease with symptoms of esophageal dysphagia “What do you mean most of the samples you have are from with milk draining from one or both nostrils after nursing. foals?” was the comment one of us made. Upon hearing a large Difficulty swallowing may also be related to other conditions number of the DNA samples that had been collected from such as a cleft palate or neurological issues. If you suspect your Friesians with megaesophagus for previous research were from foal may be having difficulty swallowing milk while nursing, foals, we realized we had missed something. Megaesophagus especially if they are older than one month, consult with your was a disease we primarily associated with older horses. A Veterinarian to rule out megaesophagus. few days later we gathered again with Ids Helinga and the geneticists from the University of Kentucky’s Gluck Equine Young horses affected with megaesophagus often present with Research Center. The previous study conducted by the KFPS symptoms of choke after they are weaned and begin ingesting included samples from horses of all ages and was unfortunately solid food or after they begin creep feeding. These horses will unsuccessful. Ids recommended this time we approach this usually present with classic choke symptoms including but study with a very strict set of parameters for study candidates, not limited to discharge of saliva and feed material from the focusing on young foals who were most likely presenting with nostrils and/or mouth, depression and apparent difficulty in an inherited (congenital) form of the disease vs. one that is swallowing. In some cases, an obstruction in the esophagus acquired. Dr. Katheryn Graves, who heads up the genetics lab will be visible and can be felt at the base of the neck. Signs of at the University of Kentucky’s Gluck Equine Research Center, choke can be very subtle and unique to the individual horse agreed to this approach and felt this method would give her team with megaesophagus. Owners and caregivers should keep close the best chance to unlock the mystery of how megaesophagus watch on their horse to determine behaviors or patterns that is inherited and hopefully one day develop a test for the disease may signal the onset of a choke episode. in Friesian horses. is a very serious and common Later that same day a call came in from an owner with a complication that can occur in any horse with megaesophagus, weanling foal in North America that had just been diagnosed but foals and young horses are especially at risk for pneumonia with megaesophagus who was interested in surrendering the due to their immature immune systems. When choke occurs, horse to the Fenway Foundation due to its critical care needs. foreign objects such as bacteria and food particles may be It was not lost on us that perhaps this was divine intervention inhaled into the lungs. While the lungs are not sterile or free pointing us in the right direction with that phone call. And that from bacteria, they do have their own distinct microbiome, was really the start of our newest adventure and challenge at which is unique to the individual horse and can be very the Foundation– managing foals with megaesophagus. sensitive. When aspiration occurs, the sheer number of bacteria in the lungs may overwhelm the natural defense mechanisms of the lungs and in short order, the horse has pneumonia. About Megaesophagus Horses may show no obvious signs during the early stages of Megaesophagus is rare in horses but it appears to be more pneumonia but may rapidly develop more advanced symptoms common in Friesian horses compared to other breeds. Utrecht such as an increased respiratory rate, difficulty breathing, University Equine Hospital in the Netherlands reported Friesians lethargy or lack of interest in nursing/eating. Advanced cases present with megaesophagus at a rate of 2.2% in contrast to of pneumonia typically present with a fever, labored breathing 0.5% in other breeds. Megaesophagus typically manifests with and nasal discharge. Aspiration pneumonia requires treatment a chronic dilation in the lower part of the esophagus, esophageal with antibiotics and advanced cases may require hospitalization strictures (narrowing) and/or a decrease in . Peristalsis and intensive round-the-clock care to resolve.

45 THE FRIESIAN

Horse Esophagus: A horse’s esophagus is 4 – 5 feet long and carries food to the stomach. Most horses with megaesophagus have an area of dilation at the lower end of the esophagus near the thoracic inlet (parallel to the first rib bone) where there is no motility followed by a small length of normal esophagus just prior to the stomach opening.

Breeders and owners should be aware megaesophagus can Additionally, if your foal or young horse is diagnosed with occur in foals and young horses. It is important to closely pneumonia related to aspiration, further investigation may be observe any foal that appears to have difficulty swallowing prudent to rule out megaesophagus. and consult with your veterinarian to rule out any other issues that may cause dysphagia. Chronic choke in young horses Unfortunately, there is no medical treatment or procedure for may be a key indicator of megaesophagus and require further megaesophagus that restores functionality of the esophagus. examination. An Esophageal Barium Study (Barium Swallow This is a disease that will not get better with time and Test) is a key diagnostic tool for evaluating megaesophagus. unfortunately symptoms may worsen over time. The typical The study involves administering a chalky, white substance prognosis for horses with megaesophagus from a veterinary called barium to the horse. The barium coats the surface of the standpoint is often poor and euthanasia is often recommended esophagus and appears white on radiographs. The procedure for foals and young horses. However, it is critical this article produces detailed images of the linings of the esophagus and conveys to readers this disease CAN be managed, even in foals. can provide insight on the motility of the esophagus and location of dilated portions of the esophagus or strictures (narrowing).

46 JULY/AUGUST 2021

Martin & Andy: Their size difference is comical, and will only grow, but it’s the key to why their relationship is so successful.

knew the odds didn’t seem to be great, we decided we had to Our Experience try and find a way to help this foal and we were willing to do whatever was in Martin’s best interest. After getting that phone call about a megaesophagus foal the owner wanted to surrender we knew the horse was going to be We arranged to meet Martin’s owners halfway for his surrender. a challenge from a management perspective. Martin’s owners We expected to see a sickly-looking foal. On the contrary, were first time Friesian owners who just wanted him to receive Martin looked very healthy and was bright with a very calm the best care. All of our knowledge and previous experience in disposition– a testament to his care thus far. We brought along caring for megaesophagus horses was with older horses who a miniature pony named Andy to pick up Martin as we planned did not seem to be as advanced in the disease as Martin. Martin to make the pony his pasture mate. We knew from our research had several severe choke episodes and aspiration pneumonia that social interaction, as normal as it could be and as much in a short period of time, so we were concerned about his as we could offer him, was going to be a critical component prognosis. After conducting some research into foals with of a normal, happy life for Martin. However, his need to be megaesophagus and consulting with veterinarians, the potential able to access a liquid diet 24/7 made it almost impossible to for Martin to have a good quality of life seemed guarded at pasture him with another full-sized horse, who would be sure best. In fact, most veterinarians recommended euthanasia for to help himself to Martin’s food. Because Andy is only 38” foals with megaesophagus. Naturally, we wondered if it was tall, he would be unable to reach Martin’s food if we arranged possible to offer this foal a normal life or if we would only be it properly and he had already previously proven himself to be prolonging the inevitable. After talking with the owners further, a great companion for foals on the farm. we understood the foal could not handle long stem forage (hay) and was on a liquid diet consisting of soaked feed and Once we arrived home it was very evident that Martin was very soaked hay pellets. We realized providing this foal with social happy to have a buddy! Martin and Andy played, and played interaction could also present a challenge with his unique diet and played. Martin also slept– a lot! Research has proven the requirements. He would need access to his liquid diet around the security of other horses is critical for horses to get the required clock to receive proper nutrition and any exposure to hay that amount of REM sleep. Martin seemed to be catching up on his his pasture-mates would need would be off limits to him due sleep and feeling very safe in his new environment. He and the to the high risk of choke. We knew we would have to develop pony spent the first few days running, playing and exploring the some very creative solutions to adequately care for Martin and woods, pastures, creeks and ponds. It was almost like seeing to give him a chance at a good life. Ultimately, even though we Martin come alive.

47 THE FRIESIAN

Prior to Martin’s arrival we researched the best way to feed him. We knew that dogs and cats with megaesophagus were often fed in a special way with feeders or chairs to elevate them and allow gravity to help food go down the esophagus. If you search “Bailey Chair” you will find some great examples of these feeders. Obviously, the size of a horse and the way they eat wouldn’t allow for the same type of set up, so we decided to build our own.

Using treated lumber, we fashioned a large box frame and filled it with gravel to serve as a strong, safe platform for Martin to put his front feet on that would be capable of holding his weight. Using more treated lumber we built a frame for two large plastic feed tubs to sit in. The result is a very basic feeder that took only a few hundred dollars to create and thus far has been highly effective at elevating the angle of the lower portion of Martin’s esophagus to help the food he swallows move through his esophagus into his stomach with the aid of gravity. The added bonus is that the feeder is much too high for the pony to access, although he is keen to help himself to any food Martin drops. Over time, we added a few minor things to the feeder, like rubber mats to keep wet food from collecting on the gravel platform and stairs. Martin’s feeder is approximately five feet off the ground and the stairs were a very nice addition to allow us to carry The feeder is a very simple the heavy five-gallon buckets with his “soup” up the stairs and pour them design and could be made into the feed tubs. The soup makes an awful mess, but it is easy to wash from a variety of materials. the entire feeder off with a hose to keep it clean. We are currently working on drawings of the feeder for anyone who wishes to build Having sorted out Martin’s social needs and his feeding set up; the specifics their own. of his diet, particularly forage, were more of a challenge. Right away when Martin arrived, it was clear he had a very strong drive to ingest something chewable and that desire was not being satisfied by his liquid diet. There Feeder Top: The tubs we was no pasture grass at the time, as it was winter, and we knew Martin had used for the megaesopha- choked previously on long stem timothy hay. Other forage/fiber options gus feeder are wide and that could be soaked such as hay cubes or beet pulp were very likely to be large allowing the horse to in pieces too large for him to ingest in large mouthfuls and would create a eat its soup without the risk of obstructing its nostrils or risk of choke. Soon after arriving, Martin was stripping the wood from his getting its face down into a feeder and eating sticks and debris from the pasture. He was also showing deep bucket. signs of ulcers with a growing disinterest in his liquid feed and signs of pain, such as biting his sides and kicking at his stomach, after eating. Knowing we needed to address his ulcers, we first placed Martin on a full course of omeprazole (Ulcergard) and additional gastric supplements and in just a few days his interest in food picked up. Next, we contemplated how we could offer him something safe to chew on. Most megaesophagus horses do well on pasture and can also successfully ingest long stem hay like orchard or timothy if it is fed in ultra-slow feed nets. Because Martin had choked previously on long stem hay, we felt that could be too much of a risk for him.

Fortunately, we were able to acquire perennial peanut hay for Martin, which is a legume hay similar in nutrition to alfalfa that is regionally available in the Southeast USA. Perennial peanut hay has very thin, fine stems and very small leaves. Our hope was this hay was in small enough pieces the risk of choke would be mitigated if fed in an ultra-slow feed net. We purchased the smallest opening slow feed net we could find (3/4” from HayBurners Equine©), loaded it with perennial peanut hay and held our breath. Anytime you introduce something new to the diet of a megaesophagus horse there is a risk of choke. Fortunately for us, the risk paid off. Martin was ecstatic to have something to chew on and has never

48 JULY/AUGUST 2021

Martin’s Feeder: Most megaesophagus horses take quickly to eating on a platform. We have observed that Martin has learned to resolve small obstructions on his own by standing on the feeder.

Martin’s Hay Net: While eating from the group would be ideal, elevating feed and water sources for horses with megaesophagus seems to help prevent choke. We have been able to play around with different height adjustments to offer him the lowest and safest feeding level.

49 THE FRIESIAN

had a choke with the perennial peanut hay. Later on, we added Martin’s Barium Study a pulley system to hang the hay net by so we could easily adjust the height for Martin. Because the net swings freely it makes it a bit more challenging for him to grab hay from it and further reduces the risk of him ingesting hay in amounts large enough to cause an obstruction. Still, his innate desire to graze has been met and he seems quite satisfied. Several months after Martin arrived, spring grass began to come in offering Martin another source of safe forage.

Today, Martin is absolutely flourishing. He and Andy have formed a special bond. Martin seems to have adopted a buffet style approach to his eating routine. He is always eager for this hay pellet and senior feed soup but only stays at the feeder for a few minutes and then he might rotate over to his hay net or head off to graze in the pasture. He never eats any one item too long, and perhaps that is his way of managing himself. Martin is incredibly smart and growing up to be a very fine-looking young horse and by all accounts our expectation is that he might make a fine riding horse and will likely thoroughly enjoy trail riding and perhaps even light competition one day.

Perennial Peanut Hay: Due to the small size of the leaves and very

megaesophagus horse that cannot eat long stem hay. It can take some fine stems, perennial peanut hay is a very safe forage option for a megaesophagus horse’s needs. trial and error to find hay available in your area that meets your

50 JULY/AUGUST 2021

There is Hope a megaesophagus horse who simply want to learn are also encouraged to join. A few of the group members were kind With elevated awareness of megaesophagus in Friesian horses, enough to offer words of advice and encouragement based on more and more resources and education are becoming available their experience with megaesophagus. today than ever before. Last year, the Fenway Foundation began a Facebook© support group for owners and caregivers “It is so easy to become consumed with anxiety when we get of megaesophagus horses. Megaesophagus can be an isolating this diagnosis. Being present, knowing there will be highs and disease for caregivers who are struggling to manage the disease, lows, reminding yourself to enjoy the time you have together particularly the intensive management strategies and special is so important.” Gail P. feeding requirements. The initial diagnosis of megaesophagus can be very overwhelming for owners. The group is a place “Focus on the solutions, not the problems. Be willing for owners to share ideas, ask questions and simply to not go to experiment and advocate for your horse by asking through their struggles alone. Members who do not manage professionals and others who have experience with ME. Be

51 THE FRIESIAN

the change, that makes the change for our beautiful pearls. on our part, these horses can live happy and relatively “normal” Remember you’re doing your best to help and they absolutely lives – and we firmly believe every Friesian deserves that know your efforts.” Megan H. opportunity.

“Realize that 99% of the time when they do choke, they will If you are managing or own a Friesian horse with megaesophagus clear it on their own.” Casey K. please join our Facebook© Group, “Equine Megaesophagus,” or feel free to reach out to the Fenway Foundation directly “Follow instructions on their feeding plan, stick with it for additional resources and information. You can reach us at regardless of the mess. Do your best, love that Black Pearl. If (888)-838-0877 or [email protected]. the time comes to say goodbye, you will have peace knowing you gave it your best.” Christy W. Author’s Note: At the time I was completing this article, the Fenway Foundation received another request from an owner “A support system is critical to making this journey easier who wished to surrender a colt with megaesophagus. The for you and successful for your horse. Seek out people who Foundation has since taken ownership of the colt, Marcus, have experience with this and learn from them. Know that and he is now pastured with Martin. Although their symptoms what works for one horse may not work for yours and over are slightly different, we are adjusting our feeding and time what once worked may require changes. It is not hard management routine to offer Marcus the same chance at a to care for them, but you must be observant, consistent and happy and productive life that we offered Martin. Both Martin proactive to any sign to avoid a choke. Your horse can live a and Marcus are the first two foals to contribute a DNA sample good life with this condition if you are proactive and consistent for our ongoing genetic research - which is pretty cool! DNA in their care.” Gay H. samples from the parents and siblings of these foals will form the first two family groups in our study. Megaesophagus is not a death sentence, particularly for foals, but it is a disease that does require very careful life-long References: management. The critical component for success of these horses is largely dependent on their owners proactively identifying Ploeg M, Gröne A, Saey V, de Bruijn CM, Back W, van the disease as early as possible and intervening with diet and Weeren PR, et al. Esophageal dysfunction in Friesian management techniques to help them avoid choke, aspiration horses: morphological features. Vet Pathol. 2014. pneumonia and other common complications. While the Foundation wishes it could provide lifelong sanctuary for Holcombe S.J., Hurcombe, B.S., Barr, H.C., Schott II. all Friesians in need, our resources are finite. We hope that 2012. Dysphagia associated with presumed pharyngeal our experience in managing foals with megaesophagus at the dysfunction in 16 neonatal foals. Equine Veterinary Journal Foundation will provide an educational road map for others who Supplement 44:105-108. one day might find themselves caring for a foal newly diagnosed with megaesophagus. Our experience at the Foundation with Foal Pneumonia, Christina S. Cable, DVM, Dipl. ACVS. megaesophagus thus far has taught us that with a bit of effort 1998. The Horse. e

Martin & Marcus: Martin (L) has taken Marcus (R) under his wing and they are getting along wonderfully.

52