Lame 12 year old Quarter horse mare

Question
I just bought a quarter horse mare She was lame in the front right leg when I bought her the previous owner before I got there had run this mare that was out to pasture for over 6 months with 2 large dogs she was  sweeting.She is one of the sweetest horses I have ever seen even with a sore leg she allowed me to ride her. i only rode her at a slow walk and for only a minute or 2 to see if she was broke to ride. He on the other hand tried to get her to lope.The only reason I purchased her was to get her away from this jerk before he hurt her more. Can you give me some help in helping her get better. if possible I do not want to get a vet involved as they are very expensive. I have started her on bute as well as a cooling leg rub similar to absorbeen Sr.. Her feet were a mess so I had her feet trimmed the farrier though she may have founder but was not sure as there was no heat in any part of her leg or foot.Can you help?

Answer
Sandra,
  You state there was no heat in any part of the foot or leg. How long ago did you have her shod? Has she improved since then or gotten worse?
  I HATE Bute. It causes as many problems as it helps. I'd recommend using Antiflam. Have you tried hosing the leg or using therapy boots?
I don't understand why you are using a cooling leg rub if there is no heat. I'd recommend poulticing the leg.
  I know you don't want to get a vet involved, but you really need to know what you are dealing with. I think x-rays and some baseline bloodwork would be a very smart investment in this mare's future.
  Best wishes!
Anne Stepien