what is this on Maizey ‘s back right arm?

最佳回答：

That looks like a mass on Maizey's arm. It could be many things and most likely it is benign. I would still recommend to have it aspirated by the vet to make sure its not a malignant tumor called a Mast Cell Tumor. The problem with this particular type is that it can look like anything. Best to play it safe.