EEE In Horse & Ratite Populations In Louisiana

The deaths of about 200 emus in mid-June come on the heels of nine horse deaths within a multi-parish area during the past eight weeks all confirmed to be caused by Eastern Equine Encephalitis (EEE).

"Last month we had horses dying of this disease and now our ratite industry is being hit by it. It's a shame we're losing these animals, because this is such a preventable disease," Bob Odom, Commissioner of Agriculture and Forestry of Louisiana's Department of Agriculture, said. "Ostriches and emus can be given the same vaccination that horses get and it is just as effective. Horses and ratites that haven't been vaccinated this year, need to have it done now."

Dr. Maxwell Lea, state veterinarian for the Department of Agriculture and Forestry, said ratite farmers have known since the early 1990s that the same virus that causes sleeping sickness in horses is also lethal in ostriches and emus. When infected, the large, flightless birds are usually stricken with severe gastroenteritis and die within 24 hours.

According to Lea, the process is a little less complicated in emus than in horses. Whereas in horses it takes mosquitos to transmit the disease, in emus it can be transmitted from a sick bird to a healthy bird and soon wipe out the whole flock.

"Research indicates that a mosquito can transfer EEE directly from one emu to another. There is also evidence that the disease can be directly transmitted from a sick emu to a healthy emu without the intervention of a mosquito or carrier bird."

"There are no known cases of humans being infected directly from an emu, but care should be taken when handling the sick birds," Lea added.

The Department of Agriculture recommends that owners should wear gloves and a face mask when in contact with a sick emu or ostrich. The face mask prevents possible inhalation of the virus. Recommendations also include thoroughly washing hands and clothing after exposure to infected birds, and separating sick birds from healthy birds.

"Again, the best way to eliminate the problem is prevention but families that own ostriches and emus must raise their level of observation to be looking for birds that are sick. If they have a bird that is suspicious, contact a veterinarian for a definite diagnosis," Odom said.

A difference between EEE in horses and the same disease in ostriches and emus is the transmission of it from one infected animal to another. In order for horses to contract EEE, a mosquito must bite an infected horse and transmit the disease to a wild bird where it replicates and multiplies without causing illness in the carrier bird. Another mosquito then has to bite the bird and bite another horse, infecting the second horse.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More