Skull size and cheek-tooth length in wild-caught and captive-bred chinchillas

Chinchillas are herbivorous rodents with teeth that all grow continuously. In captivity, they are commonly affected by dental disease. As the range of dental disease occurring in wild chinchillas is unknown, the dentition of museum specimens originally obtained from the wild was assessed and compare d with specimens prepared from captive-bred animals. Skulls from wild-caugh t chinchillas showed minimal evidence of dental disease and the teeth were all short, cheek-tooth lengths averaging 5.9 mm. Cheek-tooth lengths in zoo specimens (average 6.6 mm), clinically normal (average 7.4 min) and captiv e-bred animals with dental disease (average 10 mm) were significantly elong ated by comparison (P < 0.0001). Captive-bred specimens showed a wide range of tooth-related lesions. These results suggest that some aspect of captiv ity is responsible for the development of dental disease in chinchillas. It is suggested that the diet (its physical form and composition) is the main aetiological factor, and that provision of a diet closely matching that of wild chinchillas should significantly reduce the incidence of dental disea se in captive animals. (C) 2001 Elsevier Science Ltd. All rights reserved.