Feline infectious peritonitis (FIP) is a fatal, incurable disease that affects cats.It is caused by Feline Infectious Peritonitis Virus (FIPV), which is a mutation of Feline Enteric Coronavirus (FECV) - (Feline coronavirus FCoV).Experts do not agree on the specifics of genetic changes that produce the FIPV.t is caused by Feline Infectious Peritonitis Virus (FIPV), which is a mutation of Feline Enteric Coronavirus (FECV) - (Feline coronavirus FCoV).
Some people get mild cases of only a few days, o â¦ thers get severe cases of a few weeks or more and are hospitalized. On average, the symptoms of the flu generally last 3 - 10 days but the H1N1/09 virus lasts more typically 4 - 7, although a cough and fatigue may persist for up to 2 weeks.
Experts agree that it's going to be a nasty flu season in the U.S. this year. According to Business Insider, you can spread the influenza virus to others even before you know you're sick. The flu lasts anywhere from 5-7 days to up to two weeks. Experts say you're most contagious in the first 2-3 days. Everyone is different, of course, but it's best to wait at least 24 hours after your fever breaks before returning to work or school.