Difference between Horses and Donkeys

Donkeys and horses are different species and require different care


This article has been produced by the Donkey and Mule Protection Trust as Trustees became aware that some of the misdirected care, management and training of donkeys and mules was due to their owners not realising that donkeys and mules have some significant differences from ponies and horses. The Trust hopes to provide valuable information to a wide range of people who will better understand and take account of the particular needs and characteristics of donkeys and mules. Some of these are imperative to know before veterinary procedures are undertaken.


Donkeys have been domesticated for over 5000 years. Archaeologists discovered the skeletons of 10 donkeys in Egypt that had been buried as if they were high-ranking human officials and it appeared that donkeys were revered in those days. The bones from skeletons showed they had been used for load carrying. Also when compared to modern donkeys, morphological similarities to the wild ass showed that donkeys were still undergoing considerable phenotypic change during the early Dynastic period in Egypt.

Whereas many varieties of wild ass have a dark streak running down the spine, usually in the same colour as the mane, only the domestic donkey and the Nubian Wild Ass (Asinus africanus africanus) have a streak at right angles to it across the withers and down the shoulder.

The horse evolved in swamp/grassland/savannah country, where there was plenty of grass. When it ran out they moved on and so horses developed the need to migrate constantly.

The donkey in contrast originated in semi-arid habitat with bushland and grassland.

They evolved to survive on little food and stayed in a particular territory. Because of this the donkey leaves his dung in tidy piles that keeps his area clean, which helps with internal parasites. His digestive system enables him to get far more out of his feed than the horse. In contrast the horse leaves its dung everywhere fouling the grass and then moves on to fresh pastures. When donkeys are grazed with horses they need to be wormed frequently as they have less resistance than horses against internal worms.

It takes up to two years without equines present for pasture to be clean.

When horses were attacked their survival depended on speedy flight. However, a predator cannot chase a donkey as they will not run but attack to protect themselves. This is why donkeys will not respond to commands under pressure that are against their instincts. This has erroneously caused donkeys to be labelled stubborn. Rather they are protecting themselves against perceived danger and nothing will make them acquiesce.

A herd of horses is hierarchical, with a dominant male and mutual suspicion between stallions and mares. Horses are always stressed and on the lookout for aggression. When they take flight their first instinct is protect themselves. Donkeys are different. They group together to supervise and defend their territory. There is no dominant donkey. Every donkey in the herd, no matter how young, is responsible for the others. The need to be in a group is greater for donkeys.

A donkey will never back down and males will fight to the death.

Donkeys will all stay together, but horses will move in small groups. If a donkey has an accident the others will stay with him, or if they are domesticated go for help to humans. Horses will leave the injured friend to its fate.

The donkey survives because he does not show fear or stress outwardly. In the face of danger the donkey freezes which disconcerts his predator. It is the exact opposite when the same thing happens to the horse who will show that he is agitated, and bolt or kick out.

A horse may injure himself by panicking; a donkey will avoid injury and wait to be rescued if caught in a rope or fence.

The mule has been deliberately bred by man since ancient times. The breeding of a jack with a mare is the most common and oldest known hybrid. The inhabitants of the northern and north-western parts of modern day Turkey are said to have been the first to breed mules. Mules were known in Egypt before 3000 BC. and were also to be found in Asia Minor, Mesopotamia, Ethiopia, ancient Greece and ancient Rome. In these early times mules were bred and highly valued and cost many more times than a donkey or horse. Mules were considered the mounts of princes and the highly born.


Compared with the horse, a donkey’s and mule’s brain is larger. Donkeys and mules are alert, intelligent and cautious animals with a generally placid temperament.

If a donkey perceives danger it is more likely to remain rooted to the spot, but can take flight like a horse. Mules receive their genetic makeup from both donkeys and horses and respond variably. Both mules and donkeys can attack.

They are both naturally gregarious animals and keeping them in isolation is unkind as they need the company of another donkey or mule to be happy. Mules are very drawn to horses or ponies as their mothers are horses or ponies. Isolation may lead to mischievous behaviour and noisy braying.

Donkeys and mules bond with their owners and can grieve or fret when they are moved on to another home or taken away from their donkey/mule or pony friend.

They need lots of TLC when first with new people and may take several months to trust the new person in their life.

An important difference between mules and ponies and to a lesser extent donkeys, is that they will often work for only one person. When mules are sold or rehomed it is not uncommon for them to be unobliging to the new owner and this may never be overcome.

There is a saying “Beware of buying a mule that is onto its third home.” The mule is much more suspicious than the donkey or horse, but like the donkey they are very affectionate towards humans with whom they have bonded. If a mule has changed homes many times it may never bond with a new owner.

Donkeys do not cope well with changing homes as they bond with their owners also, but they seem to cope better if they have a donkey companion that goes too, otherwise they can become psychologically distressed and withdraw into themselves until they feel safe.

This aspect to their natures does not suit the trend of the owner passing donkeys and mules on every two to five years and moving on to some other new interest. Horses are tolerant towards humans but do not bond to the same extent as donkeys or mules.

Mules are more highly reactive than both donkeys and horses until they are mature and can be different to handle and train while still young.

When working with donkeys and mules, praise and positive reinforcement work particularly well. This is especially true for the mule. Research has shown that they make fast associations with people and situations. Once a mule has learned something it is much more difficult for them to unlearn the behaviour. A donkey will always remember but may not necessarily comply.

The best will not be brought out in a donkey or mule if the trainer tries to dominate it. Unlike horses or ponies they need to be encouraged, and not pushed or bullied. If the handler asks and does not demand they are more likely to cooperate. They only need a stern word rather than a smack if they need reprimanding; donkeys and mules are very sensitive and mules in particular, will hold a grudge if unfairly treated.

The mule can be aware of its physical limitations and this can be incorrectly interpreted as being dumb, stubborn, or mean. The truth is, mules are very smart.

Some other Facts

Movement: Mules are more inclined to be athletic and forward going with faster reactions than donkeys. Donkeys can kick forward, backwards and sideways. Donkeys and mules are more surefooted than horses and can walk on narrow rough paths without stumbling. Mules can be trained for harness as well as riding

Conformation: Apart from the obvious outward appearance of the donkey with its short mane, tufty tail, long ears, teats on male genitalia and lack of chestnuts, there are many hidden differences under a donkey’s skin, which is thinner and damages more easily than a pony’s. The mule’s mane, tail and ears vary and may fall somewhere between its donkey father and mare mother.

The donkey has a straighter shoulder than a pony. Donkey hooves are oval, narrow and more upright than horses, which are of a round platter-type shape. A mule’s hooves vary in shape, but are somewhere between a donkey and a horse.

A horse cannot see its hind feet, but both donkeys and mules can.

Stoic: Donkeys and mules are stoic and hide pain making it hard to know when it is in distress or ill. This helped to save them from predators in the wild.

Chromosomes: Donkeys 62, horses 64, mules 63 (the uneven number of chromosomes of the mule renders them almost always infertile).

Gelding: All male donkeys and mules should be gelded with the exception of jack stallions possessing highly desirable traits for breeding. Jack (stallion) donkeys and mules are not suitable as pets as they are unpredictable and likely to suddenly become dangerous without warning. Note: When gelding donkeys and mules vets should use ligation rather than clamps because donkeys and mules can bleed to death after gelding.

Gestation: A normal pregnancy can vary from 11 to 13 months. When giving injections to donkeys note that the muscle which covers the jugular vein is thicker and covers the middle third of the farrow (vets will understand this term). Note: This can vary in the mule depending on how much its physique has thrown to the horse.
There are many other differences to the anatomy.

Maturity: Donkeys’ and mules’ bones take six years to harden and only light work should be required of them until they are eight years old. They also take longer to mature mentally.

Life span: Under ideal conditions donkeys live much longer than horses or ponies. In drier climates donkeys can live 50 to 60 years, but when on rich New Zealand pastures most donkeys become too fat and few live past 30 years. Mules live 25 to 30 years in New Zealand.

Worming: Like horses and ponies, donkeys and mules should be monitored to see if they need worming. An annual check of faeces for worm eggs and only worming if necessary is good practice. Talk to your vet as to the best procedure. Picking up dung on a daily basis helps to keep pastures clean and the worm burden down as does grazing with another species of animal to vacuum up the horse and donkey parasites. Quarantine drenching of new animals onto a property is sensible and good practice. Parasite overload is one of the three main causes of colic in donkeys and mules.

Shelter: Donkeys lack the oils horses have in their coats and their hair does not lie in a manner which enables it to shed water effectively. Therefore, a shed is necessary and a cover is desirable but not essential for cold weather.
A mule will fare better in wet weather than a donkey, but not as well as a horse.

Both covering and a shelter may be necessary for donkeys in cold wet weather

Carriage driving

Donkeys are different from ponies for carriage driving as they are steadier and less likely to take fright and bolt. Most donkeys in New Zealand are driven in an open bridle and if so, they will be even safer to drive as they can see where they are going and will make allowances for obstacles. They will keep themselves and their driver safe.
It is important to remember that donkeys and mules cannot pull as much weight as a pony as their straighter hocks and straight shoulders do not give them the leverage to do so. Donkeys should not pull a cart heavier than their own weight. Donkeys (and to a lesser extent mules) have difficulty pulling weight up hills and need to be taken slowly or they will damage their muscles. Ponies on the other hand can easily canter up a hill pulling a carriage.

Mules can travel faster than a donkey pulling a carriage. If a straight breastplate is used it should not be thin. An Empathy collar is preferred as it goes around the shoulder which otherwise bears the pressure in a donkey or mule because their neck is set lower and their windpipe may be affected. Active donkeys and mules might pace and this is acceptable as long as it is balanced.

Most scientific studies in the past have centred on the horse, but studies are being done and knowledge about donkeys and mules is increasing. Perhaps this is because they have had little monetary value in the Western World in comparison with the horse or pony. However, their value to many peoples is inestimable as working animals in many countries. Here in New Zealand, when properly trained, the donkey is an ideal first mount, harness animal and companion or pet. The mule is also experiencing a come back for pleasure pursuits. Although in several countries mules have been, and still are employed by the military.

Care – some thoughts

Diet: Donkeys and mules are herbivores and eat small amounts slowly and continuously browse and graze. Donkeys’ and mules’ natural desert food is coarse grass, roughage, leaves, bark, branches, thistles etc. and they absorb more nutrition from their food than ponies. They require less protein, too much of which is harmful. Donkeys and mules are not in their natural environment in New Zealand. Our rich lush grass is the opposite of what they need. Donkeys and mules benefit from access to barley straw and coarse hay all year round. Hay must not be musty but be well harvested and smell sweet.

Lack of fibre in their diet is one of the main causes of colic in donkeys and mules.

When feeding mules it must be borne in mind that they are hybrids and as such are subject to the laws of hybrid vigour. They therefore require less food for maintenance and work than either the donkey or the horse.

Feet: Hooves are not designed for wet conditions and the ideal environment is dry underfoot. Feet need regular trimming every 6 – 8 weeks.

For donkeys the angles of their feet will be slightly steeper than a horse. In the case of mules the angle of their feet can vary depending on the conformation of the individual mule.

They both suffer from various hoof ailments which can be hard to treat in New Zealand’s soft pastures. Like ponies, donkeys and mules are very susceptible to laminitis.

Teeth: Teeth should be checked by a vet or equine dentist every two years. However, if the donkey or mule has a bit in its mouth, it should have its teeth filed every year. Painful sharp points can grow on a donkey or mule’s teeth which can cut his mouth or cause ulcers.

Again, the New Zealand environment plays a part as our pastures usually lack suitably fibrous plants. Bad teeth are one of the three major causes of colic.

If a donkey or mule is going to have a bit in its mouth it should first be checked to ensure it does not need its wolf teeth removed. Wolf teeth will cause much pain. There are bitless bridles available now.

Ears: A donkey’s large ears (mules less so) are not just to let it hear better; the donkey evolved in a hot desert climate and they enable it to keep cool. The ear’s blood vessels are close to the skin and they allow the donkey to cool its blood. This also means that a donkey’s ears are very sensitive and should not be grabbed as this will cause pain, unlike a horse whose ears are not so sensitive to touch.

Comparison of Normal Vital Signs

Daytime Rectal Temperatures

Normal Range


37.5 – 38°C


Young Donkey

36.2°C – 37.8°C

36.6°C – 38.9°C


Foals & Yearlings

37.5°C – 38.5°C

up to 39°C

Pulse at rest


32 – 70


Young Donkey

36 – 68

44 – 80

Mule – adult

26 – 40

Foals, 2 – 4 weeks

70 – 90

6 – 12 months

45 – 60

2 – 3 years

40 – 50

Respiration at Rest


10 – 14 breaths/minute


Young Donkey

12 – 44 breaths/minute

16 – 48 breaths/minute


8 – 16 breaths/minute