Feline Infectious Peritonitis(FIP) and Canineparvovirus Vaccine

Many years ago when in practice, I received a phone call from a Siamese breeder with a most perplexing problem; all of her cats were testing positive for FIP. She replaced them with new FIP free cats. several months later all were testing positive for FIP. She could not sell any of her kittens. My query to her was do you have a dog who has access to the cattery? her reply was “yes”; has your dog been vaccinated against the canine parvovirus? yes was her reply. Your cats became sensitive to the parvo vaccination which contains the coronavirus so is the FIP virus they both belong to the same coronavirus family. Therefore, the FIP titer test was positive because of the commonality of the canine and feline coronaviruses. After maintaining separation of her dog from the cattery, the problem was solved. This senerio, I am certain, Has occurred in individual house holds where there were dogs and cats cohabiting. I cannot help wondering how many cats were euthanized because of this lack of knowledge and information.