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.
Without a doubt the best hay for horses is clean hay. Hay that is moldy or dusty should not be fed to horses, even when the amount of mold or dust appears to be minor. Any hay (alfalfa, timothy, clover, fescue) that contains dust or mold can inflame the respiratory tract and impair breathing ability. Many horses develop permanent lung damage after consuming moldy or dusty hay.