Disease Du Jour: Managing Equine Laminitis

In this episode of the Disease Du Jour podcast, Andrew van Eps, BVSc, PhD, DACVIM-LA, joined us to talk about equine laminitis. He discussed the mechanisms that lead to different forms of laminitis, risk assessment, early indicators, treatment and rehabilitation strategies, and more.  

This episode of Disease Du Jour is brought to you by Bimeda.  

Mechanisms That Lead to Different Forms of Laminitis 

Van Eps explained that the most common cause of laminitis in horses and ponies is high insulin levels. “High insulin is commonly a consequence of obesity and excessive carbohydrate intake, either in the form of pasture or hard feeds or hay,” he said.  

Sepsis-related laminitis might occur if a horse has a systemic inflammatory disease such as pneumonia, colitis, retained fetal membranes, or metritis. These cases are often acute and severe.  

Less common is supporting-limb laminitis, which occurs when a horse has a painful limb condition that causes them to put excessive load on their other limb. “That is probably the least common cause,” van Eps said. “The importance of that one lies in the fact that we don’t even attempt to repair some of these complicated fractures and other really painful problems because of the risk of supporting-limb laminitis, which is quite high in those types of particularly complicated, painful cases.” 

Risk Assessment for Laminitis 

Van Eps said measuring the insulin in a horse’s blood is one good way to assess their risk of laminitis. He noted, however, that insulin can fluctuate throughout the day and with stress. Therefore, standardized dynamic tests, such as the oral sugar test (OST), are often necessary.  

Van Eps advocated for evaluating other markers of the horse’s metabolic health, such as leptin and adiponectin. “You want to have a low leptin and a high adiponectin,” he said. He noted that his research lab at the University of Pennsylvania’s New Bolton Center has measured adiponectin in about 700 lightbreed horses and has found a strong association between low adiponectin and the risk of having preexisting laminitis.  

“Even more interesting is that the ratio of leptin to adiponectin seems to be a stronger predictor than adiponectin alone,” he said. “You want to have more adiponectin than leptin, and you want that ratio of leptin to adiponectin to be less than one.” 

Other factors that can increase a horse’s risk of endocrine-related laminitis include advancing age and pituitary pars intermedia dysfunction (PPID). While traditional guidelines recommend testing horses older than 15 for PPID, van Eps believes it is more reasonable to test horses older than 10.  

Proactive Management for At-Risk Horses 

Van Eps said the first step in reducing a horse’s risk of endocrine-associated laminitis is to change their management. Some horses might need to lose body fat through a combination of diet and exercise. “Some of them don’t need to lose as much fat but perhaps just need tight dietary control because they have a propensity to make a lot of insulin in response to feeds,” he said.  

He also noted that many warmbloods carry a lot of internal visceral fat, even if they don’t appear outwardly obese. “Some of these warmbloods and other large lightbreed horses can have ribs that are showing but still have a lot of internal fat, and that is something that shows up in the leptin and adiponectin results,” he explained. “They’re lacking some of the healthy fat that makes adiponectin, which tends to be subcutaneous, and they’ve got a lot of the bad fat that’s visceral that they need to get rid of.”  

Early Indicators of Laminitis 

Van Eps said many horses with laminitis don’t display clinical signs. Therefore, it’s important to screen horses with insulin dysregulation, because by the time they’re lame, the damage is often already done.  

Subtle indicators of laminitis include loss of performance or reluctance to work, even if overt lameness isn’t present. More obvious clinical signs include divergent hoof rings, heat in the hooves, increased digital pulse, and a stilted gait that is more obvious on hard ground.  

Managing Laminitis 

Van Eps said it is important for laminitic horses to be confined initially because the tissue is weak. Analgesia provides pain relief, but it doesn’t improve the situation in the foot, and if the horse trots around the field, it will cause more damage. Mechanical support for the frog and sole is also important.  

For moderate and severe cases, van Eps said it is worth cooling the feet at the initial stages. “We’ve shown that [cooling the feet] can prevent the development of insulin-induced laminitis, and we’ve shown that it can prevent and also halt the progression of sepsis-related laminitis in experimental settings,” he said. “The caveat is that it is very difficult to apply constant cooling to the feet in a field environment.” For that reason, he advocates referring moderate to severe acute laminitis cases to a hospital for effective cooling.  

Listen to the podcast episode to learn more about managing and rehabilitating horses with laminitis and to hear about Dr. van Eps’ ongoing laminitis research.  

About Dr. Andrew van Eps 

Andrew van Eps, BVSc, PhD, DACVIM-LA, graduated from the University of Queensland School of Veterinary Science in Australia. His PhD studies focused on the effects of therapeutic hypothermia on the development of laminitis. Van Eps trained as a large animal internal medicine specialist at the University of Pennsylvania’s New Bolton Center and returned there in 2017 as the Dean W. Richardson Endowed Chair of Equine Disease Research. His research goal is to identify the key mechanisms that lead to different forms of laminitis to develop effective strategies for prevention and treatment. 

Learn more about Dr. van Eps’ research on laminitis at https://www.vet.upenn.edu/research/research-laboratories/van-eps-laboratory/. 

Related Reading

• Researchers Assess Prevalence of ID and Subclinical Laminitis in Sport Horses
• Recognizing Early Lamellar Structural Failure in Performance Horses
• How to Feed Horses Prone to Endocrinopathic Laminitis

Stay in the know! Sign up for EquiManagement’s FREE weekly newsletters to get the latest equine research, disease alerts, and vet practice updates delivered straight to your inbox.