Sudden leg twitch response in my 4yr old Corgi

Question
I have a 4yr old spayed female Pembroke Corgi who is in excellent health. She is up to date on all of her vaccinations and is happy and energetic.

Within the last week, she has developed a rather extreme version of the classic "twitchy leg" that some dogs get when you scratch their saddle region. We have had her for two years and she has never been sensitive in these areas. Now, suddenly, she twitches violently when we scratch anywhere on her lower belly or lower back.

She doesn't seem to mind it, but all that tells me is that it's not painful - this is a very snuggly, please-pet-me-at-all-times sort of dog.

She has been on the same food and in the same environment for the past two years, with very little variation. We also haven't been able to spot anything unusual about her skin.

I know that this sort of twitch reaction can be normal, but our concern is that it only just now cropped up and the "target" area is very widespread over her back and belly. Would we be seeing this reaction as part of a skin irritation like an allergy? Or is it possible this is spine/nerve related? Many thanks for your advice.

Answer
She might have just gotten more sensitive with age, or she is itchy all over and that spot just sets her off more. I have seen dogs get like this.

I would do a very careful search for fleas however. Since it her lower back and belly (prime flea hangouts) she very well could have them.

My uncle was just here with his dog who he swore didn't have a flea on her but her lower back above her tail was red and raw, another give away for flea allergies, and the dog was full of fleas once I looked her over!!

So that would be the first step here. After that if she isn't red, doesn't have fleas and is normal in every other way, then I wouldn't be too concerned.

Otherwise, have her vet look her over...