I have two fixed male cats. One 7 and one 1.5 years. They both occasionally go outside. The 7yr old came inside Thursday evening and was limping. I watched him and called the vet Friday morning. First appointment available was for Monday. Today is Sunday and he has been inside resting eating normally and is no longer limping but the 1.5yr old is. In the same left rear leg. He meows in pain when I picked him up and won't let me touch it. He was inside all day today and had been fine until this evening. Any thoughts?