I'm using the 10mm pistol, and It takes 15 fugging shots to kill a dog! It kills me in 3 hits. My special is normal, and it takes 20 hits with a base ball bat (NO EXAGERATION)
The 10mm should be fine against dogs, how many of the 15 shots actually hit the dog?
Baseball bat seems a bit weird tho, I'm level 22 in my playthrough and I'm using fists to deal with the low level criters (unarmed around 48, endurance still at 5) and dogs, molerates, scorpions (circle strafe & punching often works for the giant ones too) they go down pretty quick without me taking too much damage. Anything bigger and I usually draw a weopon (and aim for head).
Some good suggestions already such as check difficulty setting, keeping items in good condition, use VATS, try sneak mode kills and perhaps get dog meat and let him deal with these critters while you watch the show and pump a few rounds into the fight to help the dog out if you think he needs it?
I don't think the game is easy per say, but it sounds like your having a bit of a tough time