To Jog the Dog is to stroke ones penis vigorously until orgasm is achieved, in other words, Masturbation
The sudden urge to "Jog the Dog" may occur when;
1. You've been cock blocked and all out of options.
2. You're Horny.
3. You're Bored.
4. Your both bored AND horny.
5. You can't get some from your girlfriend/wife/etc.
6. Can't afford your local prostitutes.