The most pitiful thing is that they are so subject to disease and illness. And they are SO thin that if they get sick they have no reserve to draw on -- and the first thing a sick cat loses is its appetite.
A few years ago, my 14 pound male got a mysterious virus that gave him a low-grade fever for weeks. Very debilitating. We kept him alive by hand feeding him baby food and giving him subcutaneous fluids, but he lost an awful lot of weight. My daughter would hold him while I gave him two "saddlebags" of fluids, one on each side of his hips. He was very patient, but whenever I inserted the needle he would take my daughter's hand in his teeth and just hold it . . . "Now, nobody wants to get hurt here, do they?" We never did find out what the virus was, but he recovered and is perky (but grouchy) and pretty active for a 13 year old cat.