I don't know. I don't have a lot of information about this, but I was curious what your vet thought about it? I'm sorry that this is happening. I know it can be frustrating not knowing what is going on. There are a lot of threads on here with mouth problems, so if you look in the search bar on...
I have heard that too much D3 can be just as bad as not enough. I'm pretty sure they should only be getting the calcium with the D3 and the vitamins about twice a month and a calcium powder WITHOUT D3 at every feeding to help with their bones.