On average, the untreated HIV infected patient will progress to AIDS in about 5-10 years. Since 1996, the introduction of powerful anti-retroviral therapies has dramatically changed the natural progression of HIV infection to the development of AIDS.
You CAN feed your horse just hay, but you have to up the portions and it also depends upon the type of hay you are feeding. Alfalfa mix is normally the best but there again, you're goinng to have to feed more hay to make up for the not feeding grain when you are riding.
Hay provides most of a domesticated horse's forage intake. The amount of hay your horse needs every day will depend on the size of your horse and how active he is. The amount of nutrition that is in the hay also has a crucial role in how much is needed to sustain a healthy animal.