Hi Deb & Polo,
Cats giving up interest in dry food is normal. Sometimes it’s due to them wanting to change up their interests, or others due to the dryness. Potentially it could be because they aren’t drinking their water.
There are many reasons for your cat being averse to dry food including health issues or dental problems. It would be wise to get him checked with your local vet sooner rather than later just to know for sure.