Anaesthesia in Donkeys (Equus asinus)

Introduction
This presentation will discus anaes- thesia in donkeys and will focus on the differences between horses and donkeys. An introduction will be given considering the diversity that is found in donkey breeds. There are small Mediterranean donkeys weighing less than 80 kg, while the largest breeds like the French Poitou can reach the size of warmblood horses with a weight between 400 and 500 kg. Equus asinus has a varying number of chromosomes from n=27 to n=31, while Equus caballus (the horse) has 64 chromosomes. This is the reason for the infertility of both mules and hinnies, the crossbreds of horses and donkeys.

Anatomical differences
There are several anatomical differences of vital importance when performing anaesthesia in donkeys (1). Donkeys have small nasal passages and the pharynx is angled differently compared to horses. Furthermore, the pharyngeal recessus is very deep. This may not only give problems with nasogastric intubation, but it may also make tracheal intubation in donkeys more complicated. The jugular vein is covered by a thick muscle (M. cutaneus colli), which can make jugular venepuncture and catheterisation difficult. [...]