massive muscle swellings

Question
ours is the 13th home for Kacey she's 8 years old and we've had her for 6 years. she's always been fit and active with no problems until recently when every now and again out of the blue the muscles in her thighs swell massively sometimes her breathing is affected too.The vets have taken x-rays done blood tests,bile acid tests and are drawing a blank she is on 1 prednisolone and 1 frusemide tablet a day but will still have an episode from time to time.Have you ever heard of this happening before and could it be an allergic reaction to something? She's a very special girl and i hope you can help please.

Answer
Did the vet test for Lyme Disease?

If your vet did xrays and blood tests, bile for kidney disorders, and the acid tests and came up "blank" it's time to find a Boxer savvy vet ASAP and take the test results (copy of her medical records from that vet) and go forth on more testing.

It could be a number of things and only a vet that knows the Boxer breed and does not simply give up and cop out is the vet you need right now and for future medical issues.

Find THAT vet now. (call and talk to an assistant to the vet about the vet and his policies and how he practices, his beliefs and character.)