Navicular disease is not always straightforward for veterinarians to diagnose and treat, but new study findings that focus on the shape of the navicular bone (NB) and fragments found near it could help veterinarians better understand this disease in horses.

"The significance of distal border fragments of the navicular bone is not well understood," the researchers noted in the study. "There are also no objective data about changes in thickness and proximal (upper) and distal (lower) extension of the palmar cortex (rear-facing outer layer) of the navicular bone."

A recent retrospective study performed by Marianna Biggi, DVM, PhD, and Sue Dyson VetMB, PhD, at the Centre for Equine Studies at The Animal Health Trust, in Suffolk, England, examined the significance of fragments along the lower border of the NB, as well as the differences in thickness of the palmar cortex of the NB in 55 sound horses and 377 lame horses. The team hoped to better understand the distribution of distal border fragments and their association with radiological abnormalities of the NB, and to evaluate differences in the shape of the navicular bone in sound and lame horses and horses.

The sound horses used in the study had all undergone a prepurchase examination including radiographs of their front feet. The lame horses had foot-related pain and had undergone radiographic examination of at least one foot between January 2005 and December 2009. Horses used in the study were of varying breeds, disciplines, and genders. All radiographs were analyzed to determine the thickness of the palmar cortex and to measure upper or lower extensions of the palmar cortex