Happens to me every time I enter the saloon.

Have you tried running the game with no sound configured?

Mabye increase or decrease dosbox memsize value?

The installer leads you through the some menus but none of the are for sound. If afterward you select continue when there's nothing left for it to do, then you can enter sound options. However I don't think these are actually stored anywhere as the BAT and CFG files read the same regardless of choice.

Edit: I now suspect the sound options only display what has been detected and isn't for setting anything. The 2 sound cards it can differentiate between are Sound Blaster Pro and Sound Blaster 16. I used sbtype=sbpro1 and was able to rescue the sheriff a few times in a row without crashing.

I tried changing sbtype to sbpro1, but it only resulted in no sound at all. Also the game lacked in the trailer and the very first scene in the game froze.

Did you use the same installation? When I made changes I deleted the MADDOG folder and had it install a fresh one. The files are the same so it shouldn't make a difference yet somehow it does.

Here's Another oddity.
Before I changed the sbtype, and when I already had it installed, I went through the install again but selected cancel each time. After this I didn't see a crash. I can't find anything that doing this would have effected though.

The MADDOG.CFG file contains a copy of the BLASTER environment variable. If you change sbtype (which changes the BLASTER var) to something other than what's in the config file, it could cause a problem, but maybe it doesn't really matter. At any rate, I've yet to see the PP_SOUND error after several rescuings of the Sheriff. Installed and played using default settings in DOSBox 0.74.

I think it is working correct now. Have completed the game 3 times without the PP_SOUND issue occurring.

I went through the installation again, changed 'Sound Blaster 16' to 'Sound Blaster/Pro' and pressed 'Install'. It seems to have solved the problem.

Thanks for all your input.

The Patches Scrolls site has two patches for Mad Dog McCree labeled as "soundblaster fix" and "soundblaster16 fix". Sounds like they might be helpful.

Good find. I tried looking there before but I guess it's picky about the search term used.
maddog = 0
mad dog = 4