As feline viruses can be confusing to the average cat caretaker and I put myself in that category, I thought an overview page might help. The intention is to stand back and try and make sense of all the long words and slightly confusing names such as “feline distemper”, a misleading description. This is not meant to be a detailed look at this subject but I do include links to other pages on this and my blogger site.

Feline viruses, as infectious agents, need to be distinguished from other infectious agents: bacterial infections and fungal and protozoan diseases.

Cat suffering from a mild URI although can’t see symptoms – great photo by Fozzeee (trying to catch up) Flickr

Feline Upper Respiratory Disease

The most common infectious disease diagnosed in domestic cats1. Eight out of ten cases are caused by one of two highly contagious feline viruses:

  1. rhinotracheitis virus- feline herpesvirus (Feline herpes virus type 1 – FHV-1)
  2. feline calcivirus (FCV)

Transmission is through intimate contact between cats from virus particles shed in:

  • sputum (spit)
  • nasal/eye discharges

Most common form of transmission:

  • grooming, licking
  • sharing food bowls

Symptoms appear after 2 to 17 days and are:

  • inflammation of mucus membrane
  • sneezing
  • ulceration of mouth (sometimes) leading to under eating and weight loss
  • corneal lesions

FCV infections produce less severe inflammation that FHV-1. About 80% of cats that have recovered can be carriers of FHV-11. Cats also carry FCV once infected.

Feline Herpes Virus

3 Dec 2008 Viral Rhinotracheitis (RHV), which is an upper respiratory infection (URI) and a feline viral respiratory disease. Incidentally, the other major cause of feline viral respiratory disease is the Calicivirus group.


This disease is also called “feline distemper”, confusingly, I think and “feline infectious enteritis” as it causes enteritis (inflammation of the small intestine), which is often fatal in kittens. The panleukopenia virus is so called because the infection causes a severe reduction in white cell count. The word “pan” means “all” and “leukopenia” means reduced white blood cells.

This is a hardy virus that can survive in the environment under harsh conditions.  It is a highly contagious feline virus. Primary source of transmission is from the faeces. Transmission also takes place through: vomit, urine, saliva. Contact with contaminated objects spreads the disease.

Infection primarily take place in the womb and in young kittens (post natal). Infected adults can carry the virus showing no symptoms.

Symptoms – post natal in kittens:

  • abdominal pain
  • diarrhoea
  • vomiting
  • fever
  • crying
  • collapse
  • fatal

Symptoms – infected in the womb – kittens  born with:

  • cerebral hypoplasia (politically incorrect term: spastic cat)

Feline Distemper Symptom – acute and occurring quickly

Feline Panleukopenia ("Panleukopenia" means depression of the various kinds of white blood cells); Feline Infectious Enteritis (FIE); FPV; FIE

Feline Leukemia Virus

A feline virus that causes cancer. Known as FeLV. It is an RNA retrovirus for the technically minded.  The virus can only survive for minutes outside the body.

Transmission is through contact between cats, the virus secreted in saliva. Mutual grooming comes to mind. Transmission also takes place from mother to offspring in utero.

Symptoms: Feline Leukemia Symptoms

Testing: Feline Leukemia Test

Adoption: Adoptable FeLV cats

Signs Of Feline Leukemia

Before setting out the signs of feline leukemia a little background information may help. I am also making the presumption that people searching for

Feline Coronavirus

This virus is labelled: FCoV. It causes two separate diseases in domestic cats:

  1. feline enteric infection – mild infection – caused by a strain of coronavirus called FECV – symptoms: small % of cats have vomiting, diarrhoea, low grade fever, recover in 5-7 days, fatalities are rare.
  2. feline infectious peritonitis (FIP) – severe and always fatal – caused by a stain called FIPV – symptoms: See below:
  • Feline FIP

    6 Sep 2008 The Coronavirus (FCoV) is so called because the virus is circled by a Half of the cats that contract vasculitis develop Feline FIP.

  • My puppy has just eaten my cat’s poo and my cat has FIP

    1 Apr 2010 Addie DD, Jarrett, O: Use of a reverse-transcriptase polymerase chain reaction for monitoring the shedding of feline coronavirus by healthy

  • A victim of FIP

    4 Sep 2009 Last year I lost my Ivanhoe, who succumbed to FIP (feline infectious because back then many believed that Coronavirus meant FIP.

    Feline Immunodeficiency Virus

    This feline virus is labelled FIV. It belongs to the same family of feline viruses that include FeLV mentioned above. Unlike FeLV it does not cause cancer, however. There is no evidence that links it to human disease.

    Thought to infect 1-3% of all USA domestic cats. Infection is for life. Transmission is through saliva and bite wounds.  Also from mother to kitten, either in utero or in colostrum (mother’s milk).

    Occurs mainly in adult free roaming male cats. Mean age of infection is between 5 and 6 years.

  • FIV cats colloidal silver

    Today, the strides in FIV cats colloidal silver treatment are slowly becoming an increasingly known possibility for combating the scary health threat that

  • Pictures of Cats org Blog: Feline Aids

    21 Aug 2008 The feline immunodeficiency virus was discovered in California in 1986 (or 1987?). In research work carried out at the University of Florida


    We know that rabies is an invariably fatal feline virus. It is a worldwide health problem still. Of course it infects other animals including the human animal.

  • Cat Rabies Symptoms

    It is probably worth recognizing cat rabies symptoms as rabies does occur in cats in many countries and in the United States,

  • Feline Rabies

    Feline rabies may be the savior of the feral cat in Asia at least in respect of the cat meat and fur market, although I doubt it. There will still be cat.

  • Zoonotic Disease Carried by Cats

    25 Mar 2009 Rabies is by far the most serious. As I understand it, rabies is eliminated in the UK so their is almost no risk (except rabies that is

  • Cat Drooling

    In the UK rabies is eradicated but in the USA, the biggest domestic cat market, rabies exists albeit rarely as far as I am aware. Shots are commonly given

    Feline viruses – Note:

    1. page 191 The Cat, Its Behavior, Nutrition & Health by Linda P Case

    From Feline Viruses to Cat Health Problems

  • Michael Broad

    Hi, I'm a 71-year-old retired solicitor (attorney in the US). Before qualifying I worked in many jobs including professional photography. I have a girlfriend, Michelle. I love nature, cats and all animals. I am concerned about their welfare.

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