Gym Dilemma

I promised myself that this post would be brief, because it is an attempt to stall my going to the gym to run. It's not that I don't like to run, it's just that running after you've been educating young kids is almost like working out AFTER you've just run a marathon. So, here is the dilemma:

Gym right after work, or gym after a break?

Usually I go home right after work to let Tobi out, take a break, eat dinner, and then go to the gym. To be honest, the going to the gym part sometimes doesn't happen, because I have more time to talk myself out of it. I tell myself I really just need a break to decompress from the stress of school, but should that not be the reason I go to the gym??? If I go to the gym after work (after letting Tobi out, of course), I convince myself that I am a horrible pet owner because my poor dog is at home by himself again, while I am "selfishly" working out. Another cop out? I think so! What are your strategies to get you to the gym in the evenings??? Help!!!