The latest on laminitis: What veterinarians have learned and what lies ahead

Last year marked the 40th anniversary of Secretariat's Triple Crown wins, and the opening of the International Equine Conference on Laminitis and Diseases of the Foot (IECLDF), held in November in Florida, was dedicated to the efforts of the equine veterinary community in the area of laminitis.

(GETTY IMAGES/LILLISPHOTOGRAPHY)

From the time of Secretariat's death due to the disease in 1989 to present day, there have been significant advances made. This year's conference theme was "Building a Global Team," and the goal was to balance presentations of the latest scientific research and practical information with the opportunity to network and interact with other conference attendees.

James Orsini, DVM, DACVS, associate professor of surgery at the University of Pennsylvania's New Bolton Center and co-director of IECLDF, noted Secretariat's case of laminitis, recognizing that during the 1980s "we did not know what the underlying cause for his laminitis was, though it is now thought to most probably be endocrinopathic disease."

"We know much more about laminitis in 2013 than we did in 1989," conceded ­Rustin Moore, DVM, PhD, DACVS, professor and chair of the Department of Veterinary Clinical Sciences at The Ohio State University's College of Veterinary Medicine and Orsini's co-director of IECLDF. "However, we still have not solved the laminitis puzzle. In fact, the more we learn, the more we appreciate how little we really know."

Challenges abound

Moore compared what has been accomplished with laminitis to the hundreds of millions of dollars spent on research and treatment of various major human diseases. Vision 20/20, a common goal in the equine veterinary community to conquer laminitis by the year 2020, "sets the benchmark for all of our efforts, as well as comparable work in the world of equine care," stated Orsini.

Figure 1: Acute phase of laminitis. Arrow depicts the inflamed lamellar interface. Rotation or separation of the third phalanx has not yet occurred.

"Although we don't have the same level of funding that is present in human medicine, we have accomplished quite a bit with the available funds," noted Orsini. "But we need to find alternative funding sources to support research if we are to conquer laminitis by 2020. It's important for the National Institutes of Health to recognize the crossovers between human and animal health research."

The main goal of equine practitioners involved in the research, work and treatment of the disease is to aid in recognizing horses that are at risk and provide earlier intervention, thereby increasing the chances for preventive treatment and avoidance of chronic laminitis, stated Orsini.

Presentation highlights

The conference was divided into several different sections—scientific, practical and owner-based focus programs and workshops—each building on the science of laminitis research. The scientific program began with a focus on the epidemiology of the disease, since that plays such an important role in identifying at-risk horses and the factors that may put horses in jeopardy of getting laminitis.

Figure 2: Chronic phase of laminitis with rotation of the third phalanx away from the hoof wall. Lamellar wedge or "scar horn" development in chronic laminitis has a negative effect on the horse’s prognosis.

"We have a better understanding of laminitis knowing this type of information, which then allows early intervention for prevention rather than treatment strategies in managing these horses," stated Orsini. "Our goal is to be able to intervene before clinical signs are evident in the at-risk horse."

The other components of the scientific program included endocrinopathic laminitis, anatomy and physiology, and equine metabolic syndrome and inflammation.

Contributing factors for laminitis

Orsini explained that some of the reported contributing factors for laminitis are body weight, body condition score (BCS), occupation (i.e., racing, trail riding, Western competition, dressage and so on), age and the type of pain medication being used to manage the disease.

"Horses with supporting limb laminitis are generally a younger group—a racing or competing athlete that sustained a severe orthopedic injury," explained Orsini. "Horses used more for pleasure had a tendency to have a higher body weight and BCS and were not being exercised on a regular basis, which is another significant finding contributing to the development of laminitis."

Additionally, horses receiving "stronger" pain medications, in addition to NSAIDs, were more likely to have advanced disease and greater rotation.

Pathology of laminitis

Inflammation is the primary pathology occurring in horses with laminitis mediated by cytokines. This was discussed in a presentation by Patty Weber, DVM, assistant professor in the Large Animal Clinical Sciences Department at Michigan State University's College of Veterinary Medicine, who looked at the various chemokines and cytokines expressed in damaged tissue in both lean and overweight ponies.

Overweight ponies demonstrate some cytokines that are proinflammatory and contribute to the systemic inflammatory response state. These glycoproteins are very important in the disease process, and enzymes such as COX-2 are known to be detrimental to the laminar tissue. That is why COX-2-specific NSAIDs, such as firocoxib, are a better choice to manage the inflammation associated with laminitis.

Treatment for laminitis

Also discussed was the importance of cryotherapy to manage laminitis, especially in reducing inflammation. An abstract by Susan Holcolme, VMD, MS, PhD, DACVS, DACVECC, professor of large animal surgery and emergency medicine at Michigan State University's College of Veterinary Medicine, looked at 130 horses where prophylactic cryotherapy (encasing the foot and distal limb in a 5 L bag of crushed ice for 48 hours) decreased the incidence of laminitis associated with colitis.

Those horses treated with cryotherapy were 10 times less likely to develop laminitis compared with those that did not have cryotherapy. Digital ice therapy was an effective prophylaxis in horses admitted with colitis and at risk for systemic inflammatory response syndrome (SIRS).

More work to be done

One of the key goals of the IECLDF board is to expand access to key information on laminitis via the website www.laminitisconference.com, which is continually updated with relevant articles and other pertinent information. By increasing the availability of critical laminitis information to veterinarians, farriers, caretakers and horse owners, ultimately horses will receive the best care and prevention for this crippling disease.

Also, a multilingual Laminitis 911 guide, a vital information resource for horse owners, farriers and veterinarians intended to be displayed in equine barns and stables, is in the planning stages. The guide is designed to help combat equine laminitis by detailing the top 10 things that can be done if laminitis is suspected. Experts hope this piece will be completed within the next year and distributed to horse owners to improve awareness of the disease and explain the emergency treatment steps to be taken while awaiting the arrival of their veterinarian.

The group is also working on a global, Web-based resource known as Laminitis Health Partners, a world map of veterinarians and farrier teams working together to treat horses with laminitis. This will enable horse owners to locate teams of professionals dedicated to treating laminitis anywhere in the world.

"It will be a directory of global laminitis experts that have developed advanced knowledge, expertise and interest in treating these challenging cases," Orsini said.

Final focus

The take-home message from the conference was clear: The best prevention for laminitis is identifying the at-risk horse early using prophylactic methods to prevent disease and utilizing anti-inflammatory medications (NSAIDs) when necessary.

"For the future, regenerative medicine provides some promise, but we still don't have the research evidence to support its use clinically," Orsini stated. "The jury is still out on stem cell therapy, but it may prove to be very beneficial in the future, especially if used early in the disease process."

"One thing remains certain," continued Moore. "The focus needs to be on gaining a better understanding of the triggering events, various mechanisms, multiple pathways and risk factors so that we can more effectively and reliably implement preventive strategies before laminitis develops, rather than struggling with the challenges of alleviating and reversing its devastating effects."

The overall goal, as stated by Moore, is to engage veterinarians, farriers, caretakers and the greater equine community in a collaborative effort to advance, expand and disseminate knowledge through research and collective experiences in order to effectively prevent and treat equine laminitis and disease of the foot.

Ed Kane, PhD, is a researcher and consultant in animal nutrition. He is an author and editor on nutrition, physiology and veterinary medicine with a background in horses, pets and livestock. Kane is based in Seattle.