The first step in treating a horse in pain is to recognize that pain. It’s a common-sense first step, but it’s so important that Anthony Blikslager, DVM, Ph.D., Dipl. ACVS, professor of equine surgery and gastroenterology at the College of Veterinary Medicine at North Carolina State University, drives home the point whenever he talks about equine pain treatment. Pain identification ranks as a high priority for the vet school at NC State, so much so that it has developed a behavioral pain scoring system to help veterinarians determine whether a horse is in pain. The scale takes into account a number of subtle hints to enable practitioners to determine how much pain a patient may be experiencing. Is a horse willing to lift its feet freely when asked? Does the horse face its stall door watching its environment, and keep its head position above its withers? Yes to all? That’s a 0 on the pain scale. On the other end of the scale, a horse that doesn’t move, is unresponsive to another horse and is unwilling to lift its feet when asked to do so would rate a 3. “When you add it all up, you now get a much better idea of how much pain they are in,” Dr. Blikslager said. The notion of determining pain in a horse follows in the footsteps of new understanding about the importance of treating pain in horses. Until fairly recently it was believed there was a benefit to a horse’s pain because the pain would limit motion and enable the horse to stand around and get better. “But they don’t,” Blikslager said. “You get rid of pain, they will get better faster.” Like Blikslager, John A.E. Hubbell, DVM, M.S., Dipl. ACVA, a professor in the Department of Veterinary Clinical Sciences at Ohio State University, makes use of a pain scoring system, particularly in laminitis cases. When assessing the degree of pain, Dr. Hubbell suggests answering the following questions: Does the horse move freely? Does the horse rest comfortably? Does the horse appear interested in its environment? Does the horse eat and drink normally? If you cannot answer yes to all of these questions, the horse might be in pain, Hubbell suggested. Further determinations of the degree of pain can be made using scoring systems, such as OBEL scoring, which was first developed nearly 70 years ago in Sweden and has been modified since. Horses scoring a 1 are those that incessantly shift their weight at rest, and when walking they have a short, stilted gait. Horses scoring a 2 allow their feet to be lifted, and walk in a stilted manner, though willingly, and are lame at the trot. A grade 3 horse moves reluctantly and cannot trot, and resents being asked to pick up its feet, while grade 4 horses refuse to move unless forced to do so. Hubbell noted that pain and reluctance to move are often the first signs owners see when their horse develops acute laminitis. Initial strategies for pain relief include intravenous drugs like lidocaine, ketamine, alpha-2 adrenoreceptor agonists (xylazine or detomidine), nonsteroidal anti-inflammatory drugs and opioids, while treatment of chronic laminitis includes the systemic use of NSAIDs that are usually tolerated but can cause side effects often primarily related to the gastrointestinal tract and kidney, Hubbell said. Providing comfort for the horse is a key to successful treatment of laminitis, however, complete analgesia produced by local anesthetics can lead to a horse standing around overloading and quicken the progression of the disease veterinarians are trying to treat, Hubbell said. That’s why Hubbell said he seeks a balance between providing analgesia and limiting the pressure a horse places on its hooves from constantly standing. Hubbell said that long-term management of horses with laminitis requires multiple therapies, including those directed at the cause, body weight management, optimal hoof care and analgesia. Hands-on Observation is key, agreed Douglas P. Stramel, DVM, a certified veterinary pain practitioner and certified veterinary medical acupuncturist with Advanced Care Veterinary Services PA in Carrollton, Texas. But he emphasized that a thorough hands-on approach should follow a clinical observation to determine a horse’s pain and the problems causing it. “Too many practitioners, both small animal and equine, do not do a thorough examination with a hands-on approach,” Dr. Stramel said. “If you are not willing to have your hands on a patient for several minutes, palpating every joint and muscle, you are going to miss pain and possibly have a misdiagnosis. I have seen too many equine veterinarians watch a horse trot around a parking lot and then without so much as touching the horse say it needed a joint injection. “Pain management in veterinary medicine is extremely time consuming if you are going to do it right.” Following a hands-on evaluation, Stramel likes to communicate with the clients to find out what their treatment expectations are. “I constantly tell people that pain management is like a puzzle and that we might change treatment plans several times before we figure out what pieces of the puzzle will help their pet lead a painless life,” he said. “Be upfront that sometimes the condition is so painful that the best we can do is help them be less painful and not completely pain free. Without proper communication, people can set unrealistic expectations for the benefits that you can provide.” He advises changing the treatment plan as needed to find the best level of comfort, and not to be afraid of learning about new techniques or medications. One new medication Stramel has taken note of is Laminil. “Although it is not a specific medication for pain management, it seems to be a huge game changer in a horse with laminitis and we all understand how painful a condition that is,” he said. Stramel also uses intra-muscular dry needling to treat myofascial pain. It’s a human physical therapy technique that Houston, Texas, veterinarian Rick Wall began to use in small animals. “I and a few others have actually started to use it in the equine world with great success,” Stramel said, noting that Wall and Jan Dommerholt from Myopain Seminars have begun offering lessons to teach veterinarians this technique. Options Blikslager noted that a drug called Equilox is labeled for use in horses with arthritis, and there are signs Equilox is “more selective in what it targets and because of that it has less side-effects.” It’s good for horses that may have some stomach problems from NSAIDs, he said, adding the drug has been slow to take off because of some confusion about what the drug does and where it belongs in the veterinary practice. Blikslager also uses Buscopan, used for colic for years in Europe and more recently in the U.S., to prevent horses from having intestinal cramping. There are two reasons to consider the drug. It’s commonly used to treat spasmodic colic, but the drug can also be used when a veterinarian needs to palpate a horse’s rectum—it enables a horse to more thoroughly relax the rectum. However, there’s a side-effect, Blikslager cautioned. The drug can make the heart rate rise for 15 to 20 minutes. “So on horses, take the heart rate, figure out what you want to do and if has spasmodic colic, you can give it and not be concerned about the heart rate going up,” he said. “It’ll come right back down again.” Multimodal pain control is another advancement in treatment. An example of multimodal pain control that has been around for some time is treating a horse with a combination of xylazine and butorphanol. “You get more pain control than you would with either one alone,” Blikslager said. Multimodal pain control is being turned to by equine practitioners increasingly, sometimes with more than two in combination, especially in critical cases in which animals are hospitalized, Blikslager said. Veterinarians can, for example, add xylazine and butorphanol, with lidocaine dripping intravenously, to treat a patient with severe pain. “Multimodal pain control has been practiced for some time in human medicine, but it’s really taken off, first off all in small animals, and most recently in horses,” Blikslager said. Stramel, with Advanced Care, offered a list of his 10 favorite treatments: NSAIDs like phenylbutazone, Banamine, Previcox, Surpass Topical Cream; fentanyl topical patches; gabapentin; amantadine; shockwave therapy; acupuncture; intra-muscular dry needling; laser therapy; steroid joint injection; lidocaine topical patches. Bottom line, Blikslager said, is that the list for pain treatment options and ways to identify pain is much longer than it was a few years ago, and it’s growing. “We’re getting better at recognizing pain and we’re using different systems to do it,” Blikslager said. Hubble echoed those thoughts, but hopes for more developments in the field of helping horses and their owners deal with pain. “The understanding of pain mechanisms, our ability to recognize pain and new treatment methods for pain in all animals, including the horse, have made significant strides in the past 10 to 15 years, but much work remains to be done,” Hubbell said. “Our ability to use new drugs and combine therapies (multimodal treatment) has allowed us to improve comfort for the animal with a reduction in potentially deleterious side effects. Sadly, even with these advances, our inability to provide comfort via pain relief in some cases remains a significant cause of euthanasia.” Excerpt from Veterinary Practice News, April 2014 with permission from its publisher, Lumina Media. To subscribe to Veterinary Practice News, click here.
