How to Assess and Treat Acute-Onset Non–Weight-Bearing Lameness in an Ambulatory Emergency Setting

Acute-onset non–weight-bearing lameness is a common emergency complaint to the ambulatory practitioner. The initial consultation commonly contains the phrase “he was fine yesterday and today cannot bear any weight on the leg,” or, “he was sound while being ridden and suddenly came up severely lame.” The most common causes of acute non–weight-bearing lameness include subsolar abscessation, penetrating hoof injury, fracture, laminitis, severe soft tissue injury, and cellulitis. Diagnosis of the lameness can be difficult especially if the initial cause was not witnessed. Using the AAEP lameness scale, these emergency cases would be classified as Grade 4 to 5 of 5. Grade 4 is defined as “obvious lameness with a marked nodding, hitching, or shortened stride” and Grade 5 is defined as “lameness produces minimal weight bearing in motion and/or at rest or a complete inability to move.” This article is intended to assist the ambulatory practitioner in preparation of appropriate diagnostic tools and therapeutic options for an acute-onset non–weight-bearing lameness emergency. 2. History and Physical Examination