3 Main Differences Between Horses and Zebras

Is a zebra a black horse with white stripes or a white horse with black stripes? Actually, zebras are very unlike horses in temperament and physical appearance. However, both zebras and horses share similar herd social structures. Horses and zebras can mate, although the resulting offspring, zebroids or zorses, are sterile. Zebras can also successfully mate with ponies and donkeys, producing zonies and zedonks, respectively, but these are also sterile.

Body Build (Conformation)

Zebras more closely resemble donkeys than horses in conformation. Their ears are long like a donkey's. The manes are short and stand stiffly upright, like a donkey's rather than the long flowing manes of horses. Some breeds of horses such as the Fjord have a mane that will grow up stiffly like a zebras for a couple of inches, but then it falls over. Zebra manes usually grow very short so they never have a chance to fall to one side.

Zebra tails are also built like a donkey's instead of a horse's. They resemble a paintbrush in that the only part covered with hair is at the end. Horses tend to have tails entirely covered with hair.
Zebras also lack withers that horses have. Withers are a slight bump where the neck meets the shoulders. Having withers makes it far easier for a saddle to stay in place. Although differences vary in individual zebras, many zebras have a mostly level spine instead of a dip from withers to middle of the spine and up to the rounded hindquarters seen in many horse breeds.

Vocalization

Both horses and zebras have a wide range of vocal displays from a snort to a scream. Both species can snort and nicker, but the horse whinnies in a more brassy way than a zebra, which "hee-haws" like a donkey.   Zebras will also make barking sounds similar to geese honking.
In contrast, horses can whinny, which can sound quite shrill or even similar to a bugle.  When aggressive, horses can emit a chilling roar.

Temperament

This is the biggest way in which horses and zebras differ. Horses will readily be domesticated. Even feral horses that have spent years living on the range can be domesticated if given a patient and forgiving trainer. But, outside of a few instances using questionable training methods, zebras will not have anything to do with pulling a carriage or letting someone ride them.

In this way, zebras are identical to Przewalski's horse (Equus ferus przewalksii) in that this species refuses to be domesticated.  There have been rare individuals that have been able to pull carts or temporarily allowed themselves to be ridden.  However, Przewalksi's horses are a different species than domestic horses (Equus caballus) in that they have a different number of chromosomes. Domestic horses only have 64 while the Przewalski has 66. A zebra, in contrast, has 44 chromosomes. Both horses and zebras are prone to spooking, but this instinct is intense in the zebra or in zebroids.

Image of a zorse by Christine and David Schmitt for Wikimedia Commons