this is from another post
I believe my dog caught hepatitis eating human droppings around Mt Hood last year. She was getting too skinny and we discovered that her liver is badly damaged. If its hep or something it should respond to the 5 pills a day that she gets, if its liver cancer then I'll just love her as much as I can each day she's around. I could kick myself for not muzzling her when running loose in high use camping areas.
So anyway this is a warning. If you take your dog to an area where people camp, especially car camping especially with live stock, either keep her on a leash or muzzle her so she can't eat poisons or crap or worse - old McDonalds hamburger wrappers yuck. My dog passed a blue kitchen sponge after a visit to the creek one day. Now we're fighting to save her life probably because of something she ate and I'm gonna be into it to a tune of over a thousand dollars, so think about that before leting your dog run loose.
These are my own opinions based on wisdom earned through many wrong decisions. Your mileage may vary.