Feline disease are those infections or diseases that infect cats. Some of these cause symptoms, sickness or the death of the animal. Some of these are symptomatic in a cat but not in other cats. Some are opportunistic and tend to be more serious in cats that already have other sicknesses. Some of these can be treated and the animal can have a complete recovery. Others, like viral diseases, cannot be treated with antibiotics. This is because antibiotics are not effective against viruses.