The degenerative changes progress as the animal ages, but may be less severe in animals less than 15 kilograms in body weight.
Hambi leswi swikalaka swinene kuva kuri na ku lahlekeriwa ka swifuwo, swihadyani leswi laviwaka kuva kuri swifuwo leswintsongo swinene leswinga tikeku kutlula 5 kg.