Can you tell me what’s wrong? Bald patches on legs

[Itsnouse]

My male cat has been grooming his legs to the point of baldness. Mainly on the inner side so when he’s standing up you wouldn’t notice it. Obviously he needs to go to the vets but I wondered if anyone knew what it was likely to be? The bare skin looks in good condition. Could it be a stress response?

How old, often a sign of pain such as arthritis.

He’s only 3

Could be over grooming, is he up to date with flea treatments, sometimes they can get a reaction to flea bites which can be very irritating and lead to the overgrooming.

It could be that. There’s a lot of grooming going on.

One of my cats is prone to stress grooming. If the skin isn't irritated it's less likely to be flea allergy. Although my stress groomer is also flea allergic.
Presumably something has changed in his world - if he goes out, there's probably a new cat in the neighborhood. Mine got very stressed by Christmas a couple of years ago - changes, people in the house etc.
Try a plug in - feliway or similar and some calming treats..

My guess would be fleas. My cat was like this a couple of years ago. The vet prescribed a stronger dose of flea treatment. The biting and scratching stopped and the fur grew back.

Overgrooming is a sign of stress . My older cat has done it on and off through his life, he's a nervy cat and hates anything to change ! Maybe worth a vet visit .

Thanks everyone for your input. He has seemed a bit reluctant to go out so perhaps something has upset him. Though the weather has been pretty dreary and I expect the mice are hibernating and he does enjoy hunting them.

My girl has been doing this too. The vet decided it was arthritis, but we tested for cystitis and urinary infection too as that can cause it. Keep an eye on that just in case

An update
We gave him a flea treatment and waited a few days to see if it made a difference. It didn’t so he went to the vet today. They weren’t sure if it was anxiety or pain as either could be the cause of the over grooming ( as previous posters suggested) and both would mean a reluctance to go outside. He’s started on painkillers now to see if he improves.

Also depends what flea treatment you used. Many are ineffective.

My 5 y o tortie overgrooms when she feels itchy - cats can get allergic reactions which make their skin itch. The vet tried gabapentin in case she was in pain or stressed, but that didn’t work. A low dose steroid plus hypoallergenic dry food seems to keep it under control though!