WHEN THEY COME?
Dogs can come on one of these rounds, round 5, 6, or 7.
Most of my experiance is round 6. If you ever noticed, above the large door thing in the front of the lobby, on the wall it says "BEWARE OF THE 6". That could mean round 6 dogs or the number of the beast which is 6 6 6.
TIPS ON HOW TO KILL THEMEdit
First of all, you ALWAYS want to be in a corner unless your ammo is really low or you're hit really bad. You will automatically get a max ammo at the end so use as much ammo as you need but dont run out!! Automatics work well on them, but I would use a SPAS or a stakeout for 'em.