Age determination in mini-Shetland ponies and donkeys.

The accuracy of ageing mini-Shetland ponies and donkeys was assessed by correlating the appearance of specific dental features with the known ages of 106 mini-Shetland ponies and 63 donkeys. The ages of the animals ranged between 2 days and 26 years. In both species the eruption of the deciduous and permanent incisors occurred later than in horses. On the other hand, the appearance of the dental stars on the permanent incisors of mini-Shetlands and donkeys was seen at a younger age than in horses. As in most horse breeds, the disappearance of the cups, the clinical crown lengths, the presence of hooks on the upper corner and the presence of a Galvayne's groove are unreliable features for dental age determination in the pony and the donkey. Specific dental characteristics of both the mini-Shetland pony and the donkey are discussed.