Cat has gone off his food

My 10-year-old male neutered cat has been slightly off his food and yesterday did something unusual. He went to his food bowl and then backed away hissing, as though he didn’t like it. Can cats suddenly take a dislike to their food or should I see the vet about this?

- DR DAVID GRANT

Cats can be fussy about their food, but can usually be tempted by something tastier if they suddenly stop eating without being unwell.

Your description sounds like a reaction to severe pain when opening the mouth.