Donkeys, Horses Differences Studied

Researchers from the Donkey Sanctuary examined the radiographic characteristics of the feet of 157 donkeys and described the changes that occur with laminitis. The donkeys, described as the “European breed,” were typically 15 to 21 years old and weighed 360 to 395 pounds. Lateromedial radiographs were obtained from donkeys with and without a history of clinical laminitis. Several angle and length measurements were obtained of the hoof and coffin bone.

On average the dorsal hoof wall angle was 62 degrees with a nearly parallel average dorsal coffin bone angle of 64 degrees. There was considerable variation in the hoof-pastern axis, but a broken forward conformation was most common in normal feet. Donkeys with laminitis had rotation of the coffin bone within the hoof capsule, typically 12.5 degrees.

Among normal donkeys the bottom of the coffin bone created an 8-degree angle with the ground surface, which increased to about 11 degrees in laminitic donkeys. Some laminitic donkeys also showed evidence of distal displacement of the coffin bone, increased depth from the dorsal hoof wall to the dorsal coffin bone and remodeling of the tip of the coffin bone.

The authors point out that due to minor variations in radiographic parameters of the normal foot, as well as minor errors inherent in positioning, marker placement and measurement — small differences from “normal” of the order of 2 degrees or 2 mm (5/64 inches) might not be conclusive alone and should only be interpreted in context of other findings.

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