Hey guys. My rat has a small cut on his shoulder inflicted by another rat about a week ago. And today I just discovered this big lump on his shoulder about the sise of a dime. He seems fine, but he groans when we touch it. Hes eating and drinking fine. A bit lethargic but hes usually lazy. He hasn't had the lump more that 24 hours. I've been giving him amoxysisillin for the infection since he got the cut. The lump is firm and will not move under his skin. https://photos.app.goo.gl/2dA6mq8nG37vuFJR6 Link to thread describing what happpened( hes the docile rat)https://www.ratshackforum.com/threads/rat-likes-being-in-small-cage-alone.37278/ I think its an infection turned abscess. Oh, goodness I feel horrible. Please help.