Lameness

Written by Dr. Chris Stokes

2021-2022 PSEH Hospital Intern

What is equine lameness and what causes it?

Lameness is an abnormal stance or gait which may be subtle or obvious. Pain is by far the most common cause of lameness. Painful conditions in the horse include trauma, infection, muscle soreness, osteoarthritis, laminitis, or hoof abscess just to name a few. Mechanical lameness is a restriction on movement which might not be painful, but affects the horse’s gait. Some examples are locking patella which causes the hind limb to stay in extension, or fibrotic myopathy which causes the foot to “slap down” and is characteristic for the disease. 90% of equine lameness is in the foot, but other causes should not be ruled out without being seen by an equine veterinarian.

How do I know if my horse is lame?
There are multiple signs of lameness which may be obvious, or not so easily seen. Head bobbing usually indicates fore limb lameness while hind limb lameness can be a small drop or deviation of the hip on one side. Horses may not be obviously lame but “feel off” to the rider under saddle. Refusing to take the bit, change leads, tail swishing, or perform any ridden activity which has never been a problem previously can be signs of an underlying lameness.

My horse is lame or performing poorly, what now?
A thorough lameness exam by your veterinarian is the first step in determining any problems with your horse. This may reveal issues such as swelling of a specific joint or tendon, sensitive or painful areas, incorrect conformation, or something completely unrelated to the musculoskeletal system. The first step in a lameness exam is obtaining a history. Previous injuries, medical conditions, medications, and duration of issues are important for your veterinarian to be aware. Next is a standing exam where the horse’s conformation, joints, tendons, ligaments, and muscles are evaluated for abnormalities. An exam in motion is usually combined with flexion tests and regional anesthesia consisting of nerve or joint blocks to localize potential causes. Diagnostics commonly used are radiography (x-rays) and ultrasound of the affected limb initially, and can require MRI, CT scan, or Nuclear Scintigraphy (bone scan) to detect certain lesions.

What treatments are available?
There are many medications, therapies, and surgeries which have been developed over the years for our equine athletes. Anti-inflammatory medications are usually warranted in most cases of lameness. Corticosteroids are often injected into joints in cases of osteoarthritis. Muscle relaxants are often used in patients with muscle soreness along with rest and time off. Regenerative therapies include stem cells, platelet rich plasma (PRP), interleukin – 1 receptor antagonist protein (IRAP), and pulsed extra-corporeal shockwave. Other therapies can be useful with the previously mentioned treatments such as chiropractic adjustment, message therapy, acupuncture, and pulsed electromagnetic field (PEMF). Surgery, especially arthroscopy, is sometimes warranted and should be used in conjunction with medications or therapies. Ultimately it is important to know every lameness is different, and treatment should differ on a case by case basis based on recommendations by your equine veterinarian.

References
Hinchcliff KW, Kaneps AJ, Geor RJ, eBook – Veterinary Medicine 2013 [EBCVM13]. Equine Sports
Medicine and Surgery: Basic and Clinical Sciences of the Equine Athlete. Second ed. Edinburgh: Saunders
Elsevier; 2014.
Kahn, C. M. (2005). The Merck veterinary manual. 9th ed. / Whitehouse Station, N.J. ; [Great Britain]:
Merck & Co