Changes

[[Image:Normal incisors donkey.jpg|left|thumb|200px|<small><center>Normal permanent incisors (Image courtesy of [http://drupal.thedonkeysanctuary.org.uk The Donkey Sanctuary])</center></small>]]

[[Image:Normal incisors donkey.jpg|left|thumb|200px|<small><center>Normal permanent incisors (Image courtesy of [http://drupal.thedonkeysanctuary.org.uk The Donkey Sanctuary])</center></small>]]

[[Image:Ventral curve donkey.jpg|right|thumb|200px|<small><center>Normal ventral curve (Image courtesy of [http://drupal.thedonkeysanctuary.org.uk The Donkey Sanctuary])</center></small>]]

[[Image:Ventral curve donkey.jpg|right|thumb|200px|<small><center>Normal ventral curve (Image courtesy of [http://drupal.thedonkeysanctuary.org.uk The Donkey Sanctuary])</center></small>]]

[[Image:Normal teeth donkey.jpg|right|thumb|150px|<small><center>Normal teeth (Image courtesy of [http://drupal.thedonkeysanctuary.org.uk The Donkey Sanctuary])</center></small>]]

[[Image:Normal teeth donkey.jpg|left|thumb|200px|<small><center>Normal teeth (Image courtesy of [http://drupal.thedonkeysanctuary.org.uk The Donkey Sanctuary])</center></small>]]

[[Image:Skull donkey.jpg|right|thumb|150px|<small><center>Normal position of teeth within the skull (Image courtesy of [http://drupal.thedonkeysanctuary.org.uk The Donkey Sanctuary])</center></small>]]

[[Image:Skull donkey.jpg|right|thumb|200px|<small><center>Normal position of teeth within the skull (Image courtesy of [http://drupal.thedonkeysanctuary.org.uk The Donkey Sanctuary])</center></small>]]

Since donkeys evolved as browsers in often harsh, arid environments, it would be expected that their teeth would be sufficiently hard to resist the likely increased rate of dental attrition caused by the high levels of silicates

Since donkeys evolved as browsers in often harsh, arid environments, it would be expected that their teeth would be sufficiently hard to resist the likely increased rate of dental attrition caused by the high levels of silicates

and phytoliths (sand-like particles) on the herbage they had to survive on. There is anecdotal evidence that the ‘floating’ (rasping) of donkey dental overgrowths is more difficult than for horses. However, studies have yet to be made to confirm these suspicions. Micro-hardness of horse dental tissue has been assessed in Thoroughbred, draught and Arab breeds, with the Arab breed having significantly harder teeth.

and phytoliths (sand-like particles) on the herbage they had to survive on. There is anecdotal evidence that the ‘floating’ (rasping) of donkey dental overgrowths is more difficult than for horses. However, studies have yet to be made to confirm these suspicions. Micro-hardness of horse dental tissue has been assessed in Thoroughbred, draught and Arab breeds, with the Arab breed having significantly harder teeth.