A goat with a bad and painful knee

I was wondering if anyone can offer any guidance with my sick goat. The baby was about 28 days old when he developed a limp (turns out it is his right knee) it has got progressively worse over the last week and a half he is now in a lot of pain and barely able to use that leg. He has been seen by different vets but they aren't that knowledgeable and say they don't know. He has been given vitamin injections but no pain relief. He was energetic and bouncy before hand and we're worried it is someone more serious. (white muscle disease? no idea though as just guessing from his symptoms and that there is no improvement) He is still eating and going to the toilet but is in so much pain and now has referred pain on his other front leg. Has anyone else had something similar?

I can't remember exactly what it is called...there is a condition caused by bacteria entering via the umbilicus, entering the blood stream, and then settling in a joint or joints. Generally, it is treated with antibiotics. BUT, I would think any large animal or farm vet would know this. Found it, "Joint-ill" is what it is called.

https://www.merckvetmanual.com/musculoskeletal-system/lameness-in-goats/joint-ill-in-goats

This link is from the Merck Veterinary Manual.

Hi, thanks for that I will have a read. I'm trying to track down a larger animal vet in the hope they will be more knowledgeable and I can pass the details/suggestions on