Don't turn a blind eye

My five-year-old labrador retriever seems to be seeing less well. He has bumped into things on a nighttime walk and seems hesitant. Could this be cataracts? I have also read about an inherited condition that leads to blindness.

- DR DAVID GRANT

Cataracts can develop in labrador retrievers at this age. They may be inherited as a genetic mutation with signs of poor vision beginning as early as six months, and up to six years.

Apart from genetic causes, cataracts can be secondary to other diseases. These include progressive retinal atrophy, diabetes mellitus, or from eye trauma. Clinical signs are poor vision at night at first, and then gradually increasing to complete blindness.

Your veterinary surgeon will be able to diagnose cataracts by an examination with an ophthalmoscope.