Feral dogs are (have been) a serious problem in this part of the state. Typically when multiple packs are on the loose in a certain area, County Animal Control, a deputy and a USDA hunter are called in to eliminate the problem. Dogs that can't be captured by animal control are left for the hunter to dispatch and collect. Dogs are tested for rabies and the plague, a person died from the plague after being bit by a feral dog; that's why dogs are tested now for the plague.
The original article no longer has a direct link, but there's a very interesting article from March 10, 2006 if anyone wishes to scroll down this page.
http://journalism.arizona.edu/node/661
A direct pit bull attack will happen rapidly, from my experiences there will not be time for two handed grip shots or use of sights for hits. I aggressively move toward the attacking dog as I draw, thus closing the already short distance. In one instance, I was taken by surprise on my way to the shooting range on my property, with M4/64gr Power Points there was no time for sights, the bullet hit the pit bull's left shoulder, immediately stopping the charge and the bullet did not exit.
Based upon other attacks, I have complete faith in the .38 Super with high velocity handloads 124gr/125gr JHPs for head penetration. The split times of a 1911 in .38 Super are exceptionally fast, even when loaded with .357mag/125gr XTPs to the high 1400s, a .357mag bullet at .357mag velocities, in a single action 1911 platform.
Shooting dogs that have turned feral and stopping a determined pit bull attack have different handgun requirements in my limited experiences. It's not a subject I enjoy discussing, let alone writing about; however, a serious subject that hasn't been addressed thus far on this thread is that of rabies.
Those who live in the suburbs have different issues than here, a very rural high desert valley that adjoins wilderness areas.
In closing, if anyone gets the opportunity to read DEA assisted door entry reports, there's a lot of data involving determined pit bull attacks in the homes of drug dealers, surprisingly, a number of pit bulls survive being hit with .40 S&W.
Bob