Rusty is 12 years old. Lately, after we get home from work and until we go to bed he just pants. It's not unbearably hot where we are, but when it is we turn the AC on. Usually, it means he has to go outside, so I'll let him out, he does his thing and comes back in again and stands there looking at me panting. He doesn't do this on the weekends when we are home all day, just during the week when are home at night. I'm starting to get a little concerned about this behavior and am wondering if anyone has any thoughts about it.