Mules are less susceptible to hyperlipaemia than donkeys.

Mule foals are highly susceptible to neonatal isoerythrolysis due to ‘donkey factor’ antigen present in donkey red blood cells.

The position of the nasolacrimal duct varies greatly between mules.

The mule hoof is more similar to the horse or pony and is less susceptible to white line disease than the donkey.