Feral cats have been a topic of much debate over the years, with particular regard to their health risks to the domestic cat and human population. Feral cats are currently embroiled in controversy over the most appropriate method for their control. Issues of concern include the welfare of the cats themselves, public nuisances they may cause, their impact on the environment, and their impact on public health of both cats and humans. Despite these concerns, little is known about the actual prevalence of feline and zoonotic diseases in feral cats in the United States. This study will investigate the presence and frequency of heartworm disease, Ehrlichia, Haemobartonella (Mycoplasma), feline leukemia, feline infectious peritonitis, Toxoplasma, Bartonella, and Cryptosporidium in feral cats in northern Florida. This information will help define the true risk feral cats pose to the public and provide information important for public health decisions.