Dear Christopher Cat: We recently took our new cat to the veterinarian, who vaccinated her against distemper and rabies. I know about rabies, but what is distemper?

Christopher Responds: The distemper vaccine, which you’ll see listed as FVRCP on your cat’s vaccination summary, protects cats from three very contagious diseases: feline viral rhinotracheitis, calici and panleukopenia, the last of which is also called distemper.

Rhinotracheitis, caused by a herpes virus, and calici are common upper respiratory infections; calicivirus also produces oral lesions. Cats of all ages are susceptible.

Panleukopenia, or distemper, is a viral infection that wipes out the immune system’s white blood cells. All types of white blood cells are attacked, as the Greek name implies: “pan“ indicates all or every, “leuko“ means white, and “penia” refers to a deficiency.

Distemper, more common in kittens than adults, is marked by loss of appetite and energy, vomiting, diarrhea, abdominal pain and dehydration. Death is common.

Kittens exposed to the virus in utero or when young can develop a neurologic disorder that causes permanent loss of coordination, tremors or seizures.

Vaccination is important because the distemper virus is highly contagious, it can survive in the environment for a year or more, it’s resistant to most disinfectants except bleach, and it’s transmitted through hands, clothing, food bowls and litter pans. Moreover, cats that recover continue to shed the virus for six weeks.

Distemper vaccination is very effective at preventing disease. Depending on your cat’s age, your veterinarian will give two or more distemper vaccinations this year. Next year, your cat will require a single distemper booster as well as her rabies booster.