Everybody keeps talking about how expensive the doggies are, but please remember, that's only for the initial build. Once you've got your kennels breeding a set of psycho dogs, they only cost 50 gold per turn to maintain. That makes them one of the cheapest garrison supplements there is.

I find that in the Imperial campaign, when I'm flush, I'm flush. But if I stick too many expensive maintenance troops all over the place, I go broke. So my minor cities have a nice retinue of city guards and war dogs, and the expense is negligible. Sure, they won't stand up to a hardened enemy, but they're plenty good for killing peasants. Mix in some light cav for backup (also cheap on salary) and you have a great peasent-killing force ready to go.

It's not just the initial expense, folks.