My male cat is around 5 years old and has always worn a collar. I've noticed the hair has been a bit thin around there but the other day I noticed a significant bald patch on the back of his neck and patches all around the collar line. I've taken the collar off him now and will leave it off.
I'm assuming (and hoping) that it's just the rubbing from always wearing it that has caused this. If there is anyone that has had the same problem, do you know of any creams or oils that I could possibily rub into his skin to promote regrowth?
Or could this be more serious and should I take him to the vets?

Tabitha wore a collar from when she was small because her cat flap was magnetically operated. The same thing happened to her and presumably to all cats who wear collars.

Her fur grew back when she had a period without a collar but I had to reinstall the magnetic element to the cat flap when other cats started making themselves at home in my house. My cats weren't too bothered but I was!

I just made sure the collar was very loose fitting from then onwards.

I don't think there's any need for a vet visit

have you noticed him scratching it or irritating him? i think i would just leave the collar off and see if his fur grows back, i have never liked collars on cats anyway they can get caught up on branches and annoy cats in general

one of my (collarless) cats get bald patches on the collar line - my vet calls them 'hot spots' and says they arent much to worry about unless they are constant in which case they could be a food allergy

I've never noticed him scratch at it that much at all, that's why it was such a suprise when I saw it that bad. He's never had a problem having the collar on. Never objected when taking it on and off at all so it obviously doesn't bother him. I will leave it off for the foreseeable future though and hope it grows back.
Thanks for the answers

Yes, collars can be risky. Bernard lost his collar once (and his magnet) and was waiting plaintively outside my house when I got home, not understanding why he couldn't get in the cat flap. There's a cat that comes into my garden who's lost many collars.

I would prefer not to use collars but my cat flap necessitates their use. My friend has a micro chipped operated cat flap but I find it quite noisy. It took her cat about 2 months to use it as she was scared by the loud bleep it made whereas Tabitha learned to use her cat flap in just a couple of days.

I definitely wouldn't use collars by choice.

Kaida has actually lost his collar 3 times and had a replacement one in the mean time. Each time the collar has been returned by kind strangers who read the address on the tag! One gentleman did say he had to unhook him from a bush once too. I think you're right and it's safer for him to go without.