Cat nibbling at hind legs?

[Pluto207]

Hi Everyone
I adopted my cat Pluto a few months ago now and about a month or two ago I noticed that she was starting to get furless patches on the top of her back legs, licking them a lot until they started to look quite red and sore. She had been de-flead using Frontline within the second month of having her so I thought that couldn't be the cause. However I did change her litter from clay to wood pellet type so I thought perhaps due to the coincidence, this was responsible!
Anyway, her legs didn't get better after changing the litter back, so after a couple of weeks of keeping an eye on them, I took her to the vet who went through the usual questions about fleas, etc. which resulted in a conclusion of it perhaps being a psychological tick, and they gave her a steroid shot to 'break the cycle of itching'.
This seemed to work as now, a month on, one leg seems much better however the left leg has started to look bad again!
Has anyone seen this in their cats and do they have any advice? The vet also said that as she's an indoor cat, I do not need to de-flea her but I've seen that this is a common symptom of allergy to flea saliva so I'm thinking to do it again now, just in case. (I should also mention that she doesn't seem to have any skin lesions anywhere else, just on the back left leg/thigh).
Seeing as she is 100% an indoor cat, I'm also wondering if she's developed this 'tick' out of boredom and not having much in the house to hunt (she seems to be quite the hunter). I've ordered her more toys to see if I can keep her entertained!
I feel somewhat reluctant to take her back to the vet so soon, and they didn't ask permission before giving the treatment so I fear what future costs I might incur!
If it is a psychological issue arising from being an indoor cat maybe someone else here has experience or some advice?
If things don't get better in a couple of weeks then another trip to the vet it is! Thanks all.

[Mollycat]

I have seen similar once, in my old cat from a previous relationship, Purdy.

We had Sarah Cat, then Henry cat moved in and all was well. Then Purdy moved in, followed Henry from his previous home, and things were a lot less harmonious but she was determined to stay. Then Sarah died.

Purdy always suffered with fine downy fluffy back end and scabs, and she was always nibbling. Vets said flea allergy but despite all different treatments she still had bad episodes. I have never trusted this diagnosis tbh, it's the equivalent of the term idiopathic, in other words we don't know what is causing it and we can't be bothered to find out.

Henry died. We knew he had bullied her a bit, but we were totally unprepared for how Purdy changed. She was 21 at the time and since becoming an only cat she has blossomed, her "flea allergy" has vanished and she is like a new cat ... now 23 years old. It was stress all along making her pull out her own fur and lick herself raw.

As for fleas and indoor cats, I tend to agree that generally they don't need the same level of flea treatment as outdoor going cats, but you have to reach a flea-free status first. There can still be eggs in the carpets and soft furnishings for a long time after the cat has been de-fleaed. But to check, sit her on a white sheet of paper and comb her through to the roots. She should shed some little black bits. Put a drop of water on them, if they are flea poop they will run red. If they don't run they are just bits of grit. I would never treat a cat indoor or outdoor that has no trace of flea poop.

[Kay]

My Penny has always overgroomed her back legs since she came to me in April 2019 - she's around 12 now

She isn't forced to be an indoor cat, but very rarely goes outside - perhaps twice a week for 10 minutes or so - and I don't think she's stressed as such - I have read somewhere that some cats get pleasure from grooming, and overdoing it is just a habit they fall into, and which is very difficult to break - I think Penny falls into this catergory - part habit and part boredom

Having said that, although her fur is very scanty on the inside of her back legs, the skin doesn't look sore, and as she sheds very little there are no problems with hairballs , so I don't worry, and I think probably you needn't either

[fjm]

I had a cat do this out of stress. She was put onto a suitable medication to reduce her anxiety in the short term and I worked on reducing stress long term - it started when my other cat was killed on the road, and although she had never liked him I think she missed the security he provided, keeping visiting cats away. It took a while, but she did stop the licking and nibbling and the fur grew back eventually.