The Horse

OCT 2018

The Horse:Your Guide To Equine Health Care provides monthly equine health care information to horse owners, breeders, veterinarians, barn/farm managers, trainer/riding instructors, and others involved in the hands-on care of the horse.

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WHAT'SONLINE CURRENTLY ON 6 October 2018 The Horse | Laminitis causes crippling lameness associated with intense pain that shortens horses' athletic careers. Download this fact sheet to learn more about recognizing, treating, and preventing laminitis in horses. Sponsored by Soft-Ride. Kissing spines are more likely to cause clinical problems in certain horse breeds, disciplines, and age groups. Sponsored by EQ Saddle Science. TheHorse. com/160189. Learn about the risk factors associated with developing gastric ulcers, as well as diagnosis, basic management, and treat- ment, in this slideshow. Sponsored by Boehringer Ingelheim. Expert Nutrition Advice Watch: Equine Glandular Gastric Disease Do you have an equine nutrition question? Send it to Sponsored by LMF Feeds. ■ Cleaning Horse Feed Buckets: When, How, and Why? ■ Feeding Traveling Horses: Prepare in Advance, ■ Reseeding Horse Pastures in the Fall, ■ Are Hay Preservatives Safe for Horses? What do we know about this disease? Dr. Hoyt Cheramie covers anatomy, epidemiology, patho- physiology, and management of horses with glan- dular gastric ulcers. Look: Equine Gastric Ulcer Syndrome Basics Download: Laminitis in Horses Read: Kissing Spines Are Common but Not Always Career-Ending ISTOCK.COM THE HORSE STAFF THE HORSE STAFF Read: Why Is My Horse Aggressive in the Stall? A senior mare gets grumpy when other horses walk by her in the barn. Our equine behaviorist looks at possible reasons why and how her owner can manage her aggressive behavior. ■ HORSE HEALTH This award-winning e-newsletter offers news on diseases, veterinary research, and health events, along with in-depth articles on common equine health conditions. Supported by Zoetis. ■ HORSE WELFARE AND INDUSTRY Get the latest news on equine welfare, industry happenings, and horse-related business. E-NEWSLETTERS Get Horse Health News Delivered To You! ■ SPECIALTY WEEKLY E-NEWSLETTERS ■ Nutrition ■ Soundness & Lameness ■ Reader Favorites MONTHLY E-NEWSLETTERS ■ Behavior ■ Breeding ■ Farm & Barn ■ Older Horse Care ■ Sports Medicine ◆ Increased heart and respiratory rate and sweating; ◆ Glazed, pained facial expression; 1 ◆ Bounding digital arterial pulses; and ◆ Feet that are consistently warmer than usual to the touch. If the coffi n bone has displaced, horses might be reluctant to stand and can have a palpable depression immediately above the coronary band. Blood might ooze from this area. If you suspect laminitis, call your veterinarian immediately. Don't force the horse to move, and don't feed him while waiting for the vet. If possible, offer deep bedding to provide some relief from weight-bearing, even if this means bringing the bedding to wherever the horse is located. DIAGNOSING LAMINITIS Usually, clinical signs and physical examination fi ndings make diagnosis relatively straightforward. Hoof radiographs (X rays) can help vet s diagnose milder cases, determine disease severity, and devise a treatment plan. In some cases, venograms (hoof X rays taken with contrast media injected into the veins) can help guide treatment. TREATING LAMINITIC HORSES Treat cases of acute laminitis or fl are-ups as emergencies. The three main treatment goals include: 1. Minimizing mechanical trauma to weakened lamellae. Minimiz- ing trauma via trimming/shoeing is a cornerstone of treatment and ongoing management. In acute cases, soft sole padding or sand can be very useful. 2. Providing pain relief. Non-steroidal anti-infl ammatory drugs remain therapeutic mainstays; additional sedation or pain relief might be necessary. 3. Treating the underlying cause of the laminitis. Your veterinarian will try to establish and treat the basic cause—this might involve any- thing from aggressive treatment of the primary disease (in sepsis-re- lated conditions) to endocrine testing and medication for conditions such as PPID. Research has shown that cryotherapy (cooling the feet) can help prevent laminitis (e.g., in at-risk sick horses or in cases of known excessive grain intake). It's also an effective fi rst-aid strategy for LAMINITIS FACTSHEET SPONSORED BY BY STACEY OKE, DVM, MSC; REVIEWED BY ANDREW VAN EPS BVSC, PHD, DIPL. ACVIM L aminitis causes crippling lameness associ- ated with intense pain that shortens horses' athletic careers, negatively impacts quality of life, and all-too-frequently prompts euthanasia. Laminitis — damage and/or infl ammation of the lamellae — affects an estimated 7–14% of the world's equine population. 1 The tiny, inter- woven lamellae attach a horse's hoof to the underlying coffi n bone, singlehandedly supporting the animal's entire weight. Anything diminishing the lamellae's integrity, such as infl ammation, weakens their hold, causing the coffi n bone to displace (rotate or sink) within the hoof capsule. CAUSES OF LAMINITIS Veterinarians generally classify cases into one of three major categories, based on the underlying cause: ◆ Endocrine-associated, the most common form, which generally af- fects horses with insulin dysregulation, often due to equine metabolic syndrome (EMS) or pituitary pars intermedia dysfunction (PPID, formerly called equine Cushing's disease). It is exacerbated by excess starch and sugar ingestion via feed or pasture; 2,3 ◆ Sepsis-related, due to toxins in the bloodstream of ill horses (e.g., those with diarrhea, colic, retained placenta, or uterine infection); ◆ Supporting-limb laminitis, due to excessive weight-bearing on one limb as a result of injury to the opposite limb (e.g., fracture); Although the exact mechanisms that lead to laminitis development aren't completely clear, vets' understanding is progressing rapidly. Endocrine-associated laminitis is due to excess insulin's effects on the lamellae, associated with periods of high blood insulin concentrations. Supporting-limb-laminitis appears to be due to decreased blood fl ow to the lamellae. This occurs when an excessive constant load interferes with the cyclic weight loading and unloading on the limb that nor- mally helps blood fl ow. Sepsis-related laminitis is more complicated, with multiple factors, including infl ammation, acting on the lamellae. Not every case fi ts neatly in one of these three boxes. For example, exces- sive feed intake can involve both endocrine- and sepsis-related elements. Laminitis associated with corticosteroid administration likely occurs because the corticosteroids temporarily reduce insulin sensitivity. And traumatic laminitis is relatively rare and likely due to concussive tissue damage. Causes might vary but, once laminitis develops, its clinical signs and treatment approach are relatively similar. SIGNS OF LAMINITIS IN HORSES Clinical signs can be subtle (even absent), particularly with chronic endocrine-associated laminitis. However, horses with acute laminitis or chronically affected horses experiencing a fl are-up show signs including: ◆ Reluctance or inability to walk/profound lameness; ◆ Unwillingness to stand on hard surfaces; ◆ Frequent weight-shifting or lifting the feet alternately; ◆ Abnormal stance and weight distribution to relieve pressure on the affected limb(s); COURTESY DR. AMY RUCKER When the lamellae's integrity is diminished, the cof• n bone can sink or rotate within the hoof capsule. RECOGNIZING, TREATING, AND PREVENTING LAMINITIS ◆ Most Group 1 horses were 6 to 10 years old; ◆ In Group 1, 40% of the horses were used for dressage; 23% of Group 2 animals were dressage horses; and ◆ Twenty-seven (39%) of the control group horses had kissing spines; of the Thoroughbreds in the control group, six of seven had the con- dition (indicating a potential breed prevalence). CLINICAL SIGNS Horses' ground behavior in the back pain groups ranged from hypersensitivity when brushed to girthiness when saddled. When ridden, horses bucked, reared, kicked out, and displayed rear limb dragging, head-tossing, and excessive shying. Riders complained these horses were hard to get on the bit, hollow, behind the leg, slow to warm up, stiffer moving in one direction than the other, and exhib- ited poor gait transitions. DIAGNOSIS Thermography is a very useful method for detecting where the pathology might be in the horses with kissing spines (99% sensitiv- ity, but only 70% specifi city), Turner said, but the condition must be confi rmed using spinal radiography. Pathology in the Group 1 cases occurred between T11 and L2 (11th thoracic vertebra and second lumbar). "In 90% of cases, T15 was involved," noted Turner. "Not surprising, because the vertebrae change direction there." Kissing spines most commonly occurred between T15 and T18, which is roughly where the seat of the saddle rests on the ridden horse. The median number of vertebrae involved in the painful horses was four. "Dressage horses were distinctly overrepresented," he observed. "Dressage is one-third of eventing, so over 50% of horses with kissing spines (in this study) are in some kind of dressage." So, why dressage horses? "There are a lot of arguments … the SPONSORED BY BY STEPHANIE CHURCH K issing, while generally considered favorable in its usual context, isn't so great when it comes to horses' vertebral surfaces. Over- riding spinous processes — known as kissing spines — can cause severe back pain, said Tracy Turner, DVM, MS, Dipl. ACVS, but not all horses with the condition have complications because of it. Turner, of Anoka Equine Veterinary Services, in Elk River, Min- nesota, performed a study in which he determined kissing spines are more likely to cause clinical problems in certain breeds, disciplines, and ages, and that a particular combination of therapies can produce successful outcomes. Study results have shown that back pain is a major cause of poor performance in horses, and clinical signs are highly variable. Such is the case with kissing spines, so he sought to better defi ne the condi- tion, its detection, and treatments. "It's not hard to understand why back pain or anything that interferes with a horse's back will interfere with its movement," said Turner. "Any contraction in the (back) muscles causes ventral (toward the abdomen) fl exion of the spine, which makes it impossible for the horse to engage its hind end and meet its athletic potential." THE STUDY SETUP Of 4,407 horses Turner examined for lameness from Feb. 1, 2004, to Jan 31, 2011, 7% of the cases (or 310 horses) displayed back pain (reacted with pain to pressure applied along the topline or resisted or showed agitation to such pressure). He conducted a complete lame- ness exam, including thermography and radiography, on each horse to rule out other potential pain causes. This narrowed the group to 212 horses (68% of the back pain horses) with kissing spines. Turner's study comprised the following groups: ◆ Group 1: Horses with back pain and kissing spines. ◆ Group 2: Back pain, no kissing spines. ◆ Group 3: A control group consisting of 70 mature horses without back pain, either presented for "nose to toe" prepurchase exams or pretraining exams (the latter providing an opportunity to examine animals not yet impacted by training or riding). RESEARCH RESULTS In examining and comparing these groups, Turner discovered: ◆ Kissing spines make a horse three times more likely to have back pain; ◆ Group 1 contained a wide variety of breeds, but most common were Thoroughbreds, Thoroughbred crosses, Quarter Horse types, and Warmbloods; ISTOCK.COM Kissing spines can cause resistance under saddle. KISSING SPINES: COMMON BUT NOT ALWAYS CAREER-ENDING Kissing spines are more likely to cause clinical prob- lems in certain breeds, disciplines, and age groups. SPONSORED BY Special Report Thursday, Oct. 11, 2018 ❙ 8 p.m. EDT Core Vaccines Every Horse Needs The vaccines the American Association of Equine Practitioners considers core and the diseases they prevent. Sponsored by Zoetis ASK THE HORSE LIVE! Visit 1 Creating and properly maintain- ing arena and racetrack footing is important not only for equine injury prevention but also for rider safety. In recent years it's been a growing research focus for scientists around the world. One of those researchers, Mick Peterson, PhD, is the director of the University of Kentucky (UK) Ag Equine Programs, a faculty member within UK's Biosystems and Agricul- tural Engineering Department, and ex- ecutive director of the Racing Surfaces Testing Laboratory (RSTL). The RSTL, founded by Peterson and Wayne McIlwraith, BVSc, PhD, DSc, FRCVS, Dipl. ACVS, a professor at Colorado State University's College of Veterinary Medicine and Biomedical Sciences, has a more than 10-year his- tory of examining surfaces at race- tracks and equestrian sports venues worldwide, developing protocols and standards, and offering recommenda- tions. Peterson is considered one of the world's premiere experts in testing of high-level competition surfaces. Regardless of whether the RSTL team is working on a track (dirt, turf, or synthetic) or arena, its objective of surface testing remains the same. Here, we'll focus on racetrack surface testing; a later article will address arenas. "The goal (of surface testing) is to create a consistent surface and to meet the needs of the event," Peterson said. Ensuring racetrack surfaces meet the established criteria is fairly straightforward, he said. One param- eter the surface testing team can use to determine if the surface is doing its job well is race times for a particular day. However, it is critical on those occasions when a horse is injured and/ or safety questions arise that complete data is available to ensure the safest possible surface is provided for racing. Testing track surfaces involves examining its composition, as well as how the footing performs during use. Once investigators perform these tests, they can make recommendations for improvement, whether it be the foot- ing's contents or how it's maintained. Surface testing isn't a one-time event; rather, its a regular part of track maintenance. Part of their goal is to ensure proper long-term surface maintenance. The Maintenance Qual- ity System (MQS), which Peterson and the RSTL developed, involves a methodical approach of assessing and maintaining the surface prior to every event; it also assists track maintenance workers in enhancing the maintenance protocols already in place. This is the fi rst in a series of articles looking at the testing and maintenance of equine competition surfaces worldwide. N o matter the discipline—be it a horse race, show jumping competition, dressage test, reining pattern, or any other equine events that take place every year—all have one singular requirement they need to take place: appropriate and safe footing. In is Issue Feeding Healthy Senior Horses 02 Cold Spells Stress Livestock 05 Dr. Uneeda Bryant Recognized 07 Mineral of the Month: Zinc 10 Engineers inspect tracks prior to a race meet or before a change in season, depending on how long the venue operates each year, to ensure it is fully prepared for a safe competition. ANNE M. EBERHARDT/THE HORSE CA.UKY.EDU/EQUINE ❙ THEHORSE.COM ❙ JANUARY 2018 B R O U G H T T O Y O U B Y PART ONE: AN INTRODUCTION TO SURFACE TESTING Surface Testing: Keeping Horse and Rider Safety in Mind ■ Bluegrass Equine Digest is published monthly in partnership with UK Ag Equine and the Gluck Equine Research Center and is supported by Zoetis.

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