There are many things you can do if you find a sick feral cat in Delray Beach, Boca Raton, or any other city in Palm Beach County, FL. One option is to call or bring the sick cat to Palm Beach County Animal Care and Control (http://discover.pbcgov.org/publicsafety/animalcare/Pages/default.aspx). You can rent or borrow traps to safely and humanely trap the cat.
There are organizations who help treat sick feral cats on the field. Some issues like mange or injuries can be resolved with a few doses of inexpensive medicine provided by volunteers.
There are low cost vets in our area that treat feral cats brought in traps.
Justin Bartlett Animal Hospital