A cat used to come up to our house, it had a huge scar / sore on its front chest, we didn't know what it was and the cat rarely comes up too.
It was an orange, white, and gray cat if I am correct, and it had two different color eyes.
I've tried to get my mom to call an animal shelter to come look at it, cause about every other time it comes up, the scar is worse or better then it was before.
And its been coming up for more then half a year, so I am pretty certain its some kind of disease, or the owners just abuse them.