The technical term for feline distemper is panleukopenia. The Latin prefix pan- means all, leuko- refers to the white blood cells and -penia means to be decreased. Therefore a cat with panleukopenia or distemper has a decrease in all of its white blood cells.
Feline distemper is a parvo virus closely related to the canine parvo virus, and infects all species of cats in the Felidae family as well as raccoons, mink, and coatimmunid1. These parvo viruses infect rapidly dividing cells, for cats the virus preferentially infects the cells of the gastrointestinal tract and as previously stated the white blood cells. Clinical signs include vomiting, diarrhea and lethargy. Diagnostic blood work shows severely decreased white blood cell count of all white blood cell lines.
This virus is commonly found in the environment, is spread in all body secretions especially feces, and is viable in soil for more than a year so exposure is almost guaranteed1. The virus is very resistant to inactivation, but can be cleaned with a 1:32 dilution of Clorox to water.
There is no specific treatment for feline distemper as there are no antiviral medications labeled for use against the virus. Treatment involves aggressive supportive care including IV fluids, and antibiotics to treat secondary bacterial infections. Part of the challenge in treating feline distemper is that the patient has decreased white blood cells and therefore a diminished ability to fight infection. These patients are also usually not eating or unable to eat because of vomiting, which also complicates treating them. Treatment is expensive with a low percentage of success, mortality rates of 50-90% have been reported1. I have however, successfully treated panleukopenia cases, so I do recommend trying.
In light of those grim mortality statistics, prevention is critical. Feline panleukopenia as with canine distemper and parvo virus, are almost completely preventable with proper vaccination. The vast majority of cases are in kittens from nonvaccinated queens or in nonvaccianted adults. The vaccine series is begun at about eight weeks of age and repeated at 12 weeks with a yearly booster. For those not wishing to revaccinate on a yearly basis there is a blood test available to check the patient’s immune level which can guide the decision as to whether to revaccinate. Humane shelters and feline rescues often suffer from outbreaks of the disease because many of their residents have not been vaccinated.
It is unfortunate that in this day with high quality and effective vaccines that we still see cases of this deadly disease. Please see your veterinarian for his or her vaccine recommendations.
1. Saunders Manual of Small Animal Practice page 114