it affects all cats. its just that people often overfeed RTCS or do not provide ample filtration (cause they secrete a lot of waste from mucas,excrement and sumtimes vomit). therefore they r usually not very healthy. a rule of thumb is to provide a HUGEEEE tank or tub and great filtration to ensure top water quality. also, after they are over 16 inches u only have to feed them every few days or so. lastly, live food have a much higher chance of passing bacteria (especially live animals that live in water (ie fish) because fish transfer disease to other fish much easier than land animals do).