Hereditary cataracts in French Bulldogs

Cataracts are worth understanding partly for their own sake and partly because they are commonly confused with something entirely benign.

Cataract or nuclear sclerosis

Most owners who notice a haze in an older dog's eyes are looking at nuclear sclerosis — a normal age-related hardening of the lens that produces a bluish-grey appearance and barely affects vision. It needs no treatment.

A true cataract is opaque rather than hazy, blocks light, and progresses. The difference is obvious to a vet with a dilated pupil and an ophthalmoscope, and much less obvious across a room. It is worth checking rather than assuming either way.

Why the DNA test matters

As with degenerative myelopathy, an inexpensive DNA test exists for the juvenile hereditary form. Testing breeding stock and avoiding at-risk pairings prevents affected puppies entirely.

So it functions as a useful question for a breeder. Asking about HSF4 status, and getting a blank look or an assurance that it is unnecessary, tells you how much genetic screening is actually happening — regardless of what the advertisement claimed.

Surgery works

Phacoemulsification — the same technique used in humans — has a good success rate in dogs that are otherwise suitable candidates. It is expensive, it requires a specialist, and it demands committed post-operative care with frequent drops. But it restores functional vision in the majority of cases.