Incidence, types and outcomes of distal limb fractures of racehorses in Kenya: a retrospective study of radiographs (2005-2014).

Abstract

This retrospective study aimed to determine the incidence of fractures affecting the distal limbs of racehorses and their outcomes. A total of 387 radiographs each showing at least one significant bone lesion were examined. These radiographs were from racehorses examined in the period starting 1st January 2005 to 31st December 2014 at the Equine Clinic of the Jockey Club in Kenya. Radiographs showing all types of fractures were retrieved from the records archive and evaluated. Fractures accounted for 23.5% (91/387) of the cases studied and out of these, 56.0% (n=51) were of the distal limb. The commonest distal limb fractures occurred in the phalangeal bones (47.1%, n=24), followed by the proximal sesamoid bones (27.4%, n=14), metacarpal bones (19.6%, n=10) involving mainly metacarpus IV (50.0%, n=5) and metacarpus III (40.0%, n=4), navicular bones (3.9%, n=2) and metatarsal bone (2.0%, n=1). Of the phalangeal fractures, 45.8% (n=11) were chip fractures, while 41.7% (n=10) were single line fractures. Overall, horses with fractures involving the distal limb had a higher incidence for retirement (74.5%, n=38) compared to those that returned to racing (25.5%, n=13). Out of these distal limb fractures, those of the proximal sesamoid bones had a higher incidence for retiring from racing at 85.7% (n=12), while cases of navicular bone fractures that were only 2 retired from racing. The study concluded that among the distal limb fractures occurring in racehorses in Kenya, phalangeal fractures are the commonest particularly those affecting the third phalanx. Racehorses with distal limb fractures in Kenya have a high likelihood of retiring from racing owing to the fact that surgical intervention is rare except for removal of chip fractures.