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.
Typical Flu Duration. The flu typically lasts for as few as three days to as many as two weeks. If you act quickly, though, you may be able to shorten the length of time you're sick by taking an antiviral medication such as Tamiflu (oseltamivir) or Relenza (zanamivir).