Occasionally dogs do get aggressive after spaying (this usually happens in the dogs that showed these tendencies before). I think they could definately get separation anxiety from it but I wouldn't be too worried unless it doesn't go away in the next month or so.
As HHA said, if she is peeing more she needs to see a vet.
__________________ Crystal  , Ellie May (RIP)  , Rylee Finnegan  , and Gracie Boo🐶 |