We have been fostering for a few months and the agency pays for all food, care and litter. There are many people who have the room and love, but not the additional expenses. Fact is, true foster agencies usually are non profit and qualify for many donations and discounts. All costs are usually much cheaper than a private home can get it for. Example, the medication we just bought for $50, if I had been thinking I could have called the lady that runs the rescue we help and got it for about $15.00.