The clinics are designed for healthy feral cats only. (arlboston.org)
That's when they began sterilizing healthy feral cats who came into their shelter, and returning them to the locations where they'd been thriving. (maddiesinstitute.typepad.com)
Most of us would probably prefer to have a small, healthy feral cat population, rather than a larger Norway rat and seagull population in habitats where those are the only options. (cfa.org)