In order to ensure that there are no injuries and that all introductions are positive a desensitization and counter-conditioning program is the best way to ease a new cat into a household. Begin by confining the new cat to a room or portion of the home with its own litter and water. Allow the existing cat to continue to have access to the rest of the home. This arrangement provides a separate territory within the home for each cat, and allows both cats an opportunity to adapt to the smell and sounds of each other, without the possibility of direct contact or physical confrontation. If the new cat is housed in a screened-in porch or a room with a glass door, it may also be possible to allow the cats to see each other through a safe partition. When the cats show no fear, anxiety, or threat toward each other, then progress to controlled exposure exercises. Training should occur when the cats can be occupied in a highly "rewarding" activity such as feeding, play, or treats. Provided both cats are far enough apart to minimize the possibility of aggression, and the reward is sufficiently appealing, the cats will focus on the rewards rather than each other. In addition, if the rewards are saved exclusively for these introduction times, the cats will quickly learn to expect "good things to happen" in the presence of each other. In addition to ensuring that the cats are at a safe enough distance to minimize fear, both cats (or at least the one that is likely to be the aggressor) can be confined to an open wire mesh cage or a body harness and leash. This will ensure that the cats can neither escape nor injure each other. It is safest to begin the first few introductions, not only at sufficient distance to reduce fear, but also with one or both cats in cages or on body harness and leash, so that they can neither retreat, or injure the other cat. If the cats have been in cages during the first training session, they can be placed in each other’s cages at the next session (so that the cats are exposed to the other cat’s odor). The cages can be moved progressively closer, provided the cats show no fear or anxiety and remain interested in the food. Once the cats will eat and accept exposure in either cage when close together, keep one cat in the cage and the other out during feeding. The situation is then reversed at the next session. As a final step the distance between cats can be increased again, with both cats out of their cages. A body harness and leash can be used to ensure additional safety. Over time the cats are fed closer together until a point where the cats can eat, or take treats, in each other’s presence.