Donkeys are important animals throughout the world. They are used as guard animals to protect small ruminants such as sheep and goats; as companion animals; used to halter break calves and foals; and used for work in many parts of the world. Donkeys come in all sizes from minis to mammoths. Dr D.G. Pugh indicates the mini donkey hails mostly from Sardinia and Sicily and stands about three feet tall at the withers and has a dorsal cross on its backs. The burro is a smaller donkey and originally came from Spain, while a standard donkey is three to four feet tall at the withers. The large standard is four to four and a half feet tall. Mammoth donkeys are over four and a half feet tall at the withers.

Sometimes horses and donkeys are bred and the combination can be confusing as a cross between a male donkey (jack) and a horse mare will be sterile; the female is called a mare or a molly mule and the male would be called a horse, stud or a john mule. Johns should be castrated and the mule will have smaller ears than the jack but longer than the mare. The mule will reflect its parentage, so a jack crossed with a gaited mare will also have refined gait. The hinney is the opposite pairing and is much less common than the mule as it is the cross between a horse stud and a female donkey (jenny) and it is less common because the conception rate is poor.

Disease, vaccination and deworming programs are similar to horses except adult donkeys do not have resistance to roundworms as do adult horses, so adult donkeys need to be dewormed with products effective against roundworms. Also, trimming donkey feet is much different than trimming horse feet so choose a farrier familiar with donkeys.