Concerned about my cats coat

[violeticecream]

Hi all
My cat is 6 years and has always been fit and healthy. Over the last few weeks I have noticed that his fur seems to have changed. He is shedding like crazy and his fur seems to be clumpy and sort of going in ridges. He is eating fine as usual and seems happy. His flea treatment is up to date. I have a furminator and have been using it but he hates it so not that often.
Has anyone's cat fur home like this? I wondered if a supplement like salmon oil would help. First photo is now and second photo how he looked a while back.

Hope someone can advise

How’s his weight? My mum’s cat’s fur looked like this when he had an overactive thyroid. Was eating ok but got a bit thin.

Fleas?

He's a bit young for hyperthyroidism, but if the clumps are sort of glued together, I'd get him checked out. Other signs are weight loss, eating well.

Thanks. Yes I have read about hyperthyroidism but thought he would be too young for that.
A trip to the vets me thinks ....

Was about to suggest thyroid too. Our old cat's coat got dry (flaky skin too) and rough looking before diagnosis - she was a bit older though. Fingers crossed the vet can shed some light. If it's thyroid, it's very treatable.