So 3 weeks ago millie had TPLO surgery on a ruptured ligament and is doing well recovering. Yesterday she was laying on her side and my eldest son (11) rubbed her belly/side and she barked and snapped at him. She of course didn’t actually touch him with her mouth but it was enough for us all to notice. He was rubbin her firmly I guess but jut the same as he has always done; she is such a big softie. This is our second mastiff breed so my kids are great around them. It really shook him up though as she has never done this before. This morning she did the same to me without the bark. Vet appointment booked for 3:30 this afternoon but any ideas? She finished second season same time as op, 3 weeks ago so I must admit that I’m on pyo alert (due to be spayed April) . I wondered if tender tummy could be related but there aren’t any other obvious signs .