I had a cat once who nearly turned himself inside-out trying to get out of a harness when we put it on him for the first time. He was absolutely determined to get out of that thing and finally he did, and we never tried to put it on him again. When my current kitty was little, we had big plans for taking her on walks with us and bought her a little harness. I started her out by putting a teensy collar around her neck but she kept trying to get out of it. She seemed so frustrated with the thing that I finally gave up and took it off of her. I never tried to get her to wear one again, so our plans to harness our cat for outdoor walks was and probably never will be realized. She's three years old now and pretty much set in her ways, so it's unlikely that we will get back into that groove again. Still, it would have been nice, had we been more determined than that tiny kitten. I've heard that if you start the cat on a harness when he's very young, it will work better. However, most cat-sized harnesses are designed for adult cats, so even the tiniest one we could find pretty much swam on her and we knew that wouldn't work... hence, the collar, which was actually just a wrist-band for a watch. It fit her neck perfectly but she didn't like it, and I didn't push it. You have to be more determined than the cat and try not to watch as the cat shows his or her misery. I failed at that last point, unfortunately.
