A hinny is the result of breeding between a female donkey and a male horse. A hinny is said to have the body of a donkey and the extremities of a horse.

Because a donkey mare is smaller than most horses, hinnies are generally smaller than mules and are less common than mules. It is extremely difficult to tell the differences between a mule and hinny, therefore hinnies are often mistaken for mules.

Male and female hinnies are generally referred to in the same way as male and female mules.

Male mules and male hinnies are anatomically normal. They are extremely difficult to handle and should be castrated, to help with their temperament and make them safer to manage.

Mules and hinnies come in a wide range of colours depending on their parents: from plain solid colours to paint and appaloosa markings.

As donkeys have 62 chromosomes and horses have 64 chromosomes the result of their inter-breeding, a mule or hinny, has 63 chromosomes. This odd number of chromosomes makes it extremely rare for a mule to breed.