Impact of facial conformation on canine health: corneal ulceration

Brachycephalic breeds more likely to suffer from canine corneal ulcers

Source: R.M.A. Packer, A. Hendricks, C.C. Burn
PLOS One. 2015 vol 10 no 5: e0123827 .DOI:10.1371/journal.pone.0123827

Dogs from extremely short-nosed. or brachycephalic breeds have become increasingly common due to artificial selection, and this has been linked to an increase in eye disorders. This study examined whether corneal ulcers, which appear on the surface of the eye, are linked to extreme facial features such as brachycephaly. The study involved 700 dogs at a UK hospital, and included 31 dogs suffering from corneal ulcers, 30 of which were pedigree dogs, including brachycephalic breeds, such as bulldogs, pugs, shih tzus, and cavalier King Charles spaniels.

These short-nosed breeds had a twenty-fold greater possibility of suffering corneal ulcers, than dogs with normal or longer noses. This may be because brachycephalic dogs tend to have protruding eyes, and they may not be able to protect their eyes by blinking easily. Nasal folds were associated with an almost five-fold risk of corneal ulcers, while an increase in the relative width of eyelid aperture of more than 10% was linked to a more than tripled risk of corneal ulcers, and exposed eye-whites with an almost three-fold risk of corneal ulcers.

Breeding for short muzzles and linked characteristics such as nasal folds can increase the risk of corneal ulcers. Dogs could be bred for longer muzzles, in order to lessen the chances of their suffering from corneal ulcers.