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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30 TheHorse.com THE HORSE February 2016 gallons) for an aver- age 500-kilogram (1,100-pound) horse—and can lose a lot of blood before they exhibit signs of shock, up to 8 to 10 liters," she said. ■ Watch for lameness or gait abnormali- ties that could indicate damage to an internal structure. ■ Southwood said it's wise for the veterinarian to conduct a physical exam before treating the wound. An increased heart or respiratory rate or pale mucous membranes, for instance, could indicate the horse is in the early stages of shock or suffering from criti- cal blood loss, which could significantly alter a practitioner's treatment plan. ■ She also recommended sedating the horse and/or administering a local an- esthetic early in the treatment process. ■ Once the affected area is numb and/or the horse is sedated, the veterinarian can begin examining and treating the wound. Southwood suggested apply- ing sterile lubrication to the wound before clipping and preparing the area aseptically (in a sterile fashion). She re- minded practitioners to clean the hoof, if applicable, as it can carry substantial bacteria and foreign material. ■ Next, the practitioner ligates (ties or closes) the affected area's blood vessels to prevent further bleeding. "This can be challenging in the standing horse and in a field setting and in some in- stances may require general anesthesia with good lighting," she noted. "Referral to a surgical facility may be necessary." ■ The next step—exploring the wound and palpating the leg—is crucial, Southwood stressed. This is where the veterinarian will have the best chance to evaluate, lavage (flush and clean), and debride (surgically remove the dead or damaged tissue around) the wound. "Do this very thoroughly," she said, to ensure the remaining tissue is healthy and has the best chance to heal. "Any wound on the limb, especially the distal (or lower) limb, may involve a joint, tendon, tendon sheath, or bone," she said. "Even small puncture wounds that appear insignificant can be life- threatening if a deeper structure is involved and becomes infected." ■ Then it's time to close the wound, if possible, and apply a bandage. ■ She also urged attendees to radiograph the affected area to be sure bone isn't involved. Even if a fracture or bone chip seems unlikely, it's best to confirm internal structures are intact. Following initial treatment, Southwood said she puts patients on stall rest and ad- ministers antimicrobials and NSAIDs as needed, urging practitioners to consider the consequences of wound infection. Prognosis for most lacerations is good to excellent if caught and treated early, Southwood said. It can worsen depending on wound severity, structures involved, infection, and other factors. Joint Therapies: What to Know Navigating the formidable array of equine joint therapy options becomes easier when you have a good under- standing of each treatment and how it works. Laurie Goodrich, DVM, PhD, Dipl. ACVS, associate professor of surgery and lameness in the Department of Clinical Sciences and the Orthopaedic Research Center at Colorado State University's Col- lege of Veterinary Medicine & Biomedical Sciences, in Fort Collins, reviewed some common options. The goals of joint therapy center around removing the inciting cause of pain, reducing inflammation, and reach- ing the best possible outcome for the horse. Goodrich said the ultimate goal is to preserve the internal structures, such as cartilage, which isn't possible once the horse develops progressive joint disease or severe osteoarthritis. She said veterinarians rely on symp- tom- and disease-modifying treatments to achieve this. Symptom-modifying treatments can help the horse feel more comfortable and move easier, but they do not stop disease progression. Disease- modifying treatments, on the other hand, can slow, stop, or even reverse the degen- erative process. She reviewed the following options: Corticosteroids This group of medica- tions, considered a mainstay in treating equine joint inflammation, has evolved substantially over time, she said. Specific corticosteroids include: ■ Triamcinolone, which can reduce lame- ness and increase range of motion, Go- odrich said. Researchers learned that it can help protect cartilage and has both symptom- and disease-modifying ef- fects. She cautioned that it can induce laminitis in some horses; however, she also noted that study results revealed that just three of more than 2,000 horses receiving 40-52 mg of triamcino- lone developed laminitis two to three months following administration. So the risk for laminitis development ap- pears to be fairly low. ■ Researchers found that administer- ing betamethasone into the joint had no detrimental effects on cartilage or subchondral (beneath the cartilage) bone, so it appears safe to administer to horses whose cartilage has not been damaged. ■ Methylprednisolone, on the other hand, does appear to have deleterious effects on cartilage—even at low doses— despite the fact that it can help reduce inflammation, Goodrich said. She advised against using methylpredniso- lone in horses if their cartilage is still in good shape. After stopping blood fow, the veterinarian will evaluate, lavage (shown here), and debride the wound. KIM AND KARI BAKER While stopping hemorrhage is critical, horses do have a lot of blood … and can lose a lot of blood before they exhibit signs of shock." DR. LOUISE SOUTHWOOD