Anatomy and imaging features of the dew claws of the water buffalo and cow

Dew claws of ruminants are rudimentary of 2 and 5 digits and usually do not have functional action. Most studies about the dew claws were done on the diseases and shape-abnormality.
Because no comprehensive study has been done on the normal features of dew claws, especially in the water buffalo which is an important animal in Khouzestan, this study was performed on anatomy and radiology of the dew claws in the water buffalo and cow.
136 dew claws from 11 water buffaloes and 6 cows were examined morphologically, morphometrically, and radiologically and their similarities and differences were clarified.
Morphologic result showed that the dew claws were prismatic in shape; their bases were attached to skin at the level of the palmar or plantar surfaces of the fetlock joints. They had two bony ossicles in most cases as proximal and distal ones, but the ossicles in lateral dew claws of thoracic limb in the water buffalo were 3 in number. Proximal ossicles of the water buffalo were dumbbell-shaped, and were irregular or drop-shaped in the cow. Distal ossicles were nearly similar to the third phalanges of the main claws which were pyramid-shaped in water buffalo and triangle-shaped in the cow. Morphometrically, the measurements of the hoof and bony structures of the dew claws in the water buffalo were muchgreater than those of the cows.
Although dew claws in both animals morphologically shared some similarities, there were morpho- metrically significant differences between the dew claws of the water buffalo and the cow. Being larger than the structures in the water buffalo may provide better adaption in static and dynamic of the animal in soft and swamp grounds. Radiologically, the best view for examination of dew claws and their elements was oblique view.