Wow, I never would have thought Las Vegas was a popular place for dog fighting, or for pit bulls altogether. Thats terrible.
You need to talk to your local authorities. Call the police or animal control and ask them what you can do as someone that cares and wants to help these dogs. They will most likely give you some tips on what you can do or what you can look out for.
If you do see dogs without proper food, water, shelter, you need to report that...those are basic needs that need to be met - otherwise, it is animal neglect and needs to be reported. Once they come, you can also tell them what you see..that these dogs are chained 24/7..there they are never socialized...etc...report what you see...tell them your concerns..
Don't give up...sometimes it takes pushing and shoving to get authorities to do their job - believe me I know, I've dealt with a few of them..but keep trying..they will respond..and you may end up making a positive change, even if it is for only one or two dogs..you will be making a big difference in the life of one of these animals.
Don't stop caring