My two year old male rat is have a tumor removal surgery today. The tumor is quite large and on his side. They're going to give him a collar and they're recommending I leave it on for several days. Based on my research I think I'll take it off immediately and leave it off unless I notice him chewing the wound. Is this the right thing to do? They're also telling me to keep him separated from my other rat for several days. How necessary is this? My rats are very close, and I'm worried they will both get depressed if separated for long. Any advice would be much appreciated.