Wednesday, January 25, 2006

Equine flu invades valley, but humans can't catch it

Jane Moorman News-Bulletin Staff Writer; jmoorman@news-bulletin.com

Los Lunas It's flu season, not just for humans, but for equids — horses, donkeys and mules — as well.

Valencia County veterinarians are seeing an enormous number of equine influenza cases, according to Los Lunas veterinarian Donny MacDougall.

"There's a rash of it right now. We're seeing two to 10 cases a day," said the owner of Los Lunas Animal Clinic of the flu season that lasts from January to May. "Foals, malnourished and elderly equids are most susceptible to the virus."

Equine influenza is spread by respiratory secretions when an animal sneezes. The mucous droplets can contaminate inanimate objects and people that transport it to another horse.

"Unlike the avian flu (bird flu), humans cannot contract the flu from their horse, donkey or mule. But they can transmit it from one equid to another," he said.

"The influenza virus can get on a rope or bridle and even the hands of a person, which then touches another horse. Virtually 100 percent of the horses that are exposed become infected."

The most common source of infection and outbreak is the introduction of a new animal into a herd. It is recommended to isolate any newly acquired animals to ensure that they are not infectious.

While the virus is highly contagious, MacDougall said prevention is possible with a vaccination. The vaccination is among the equids' annual spring shots but MacDougall says that, if people wait until then, the flu season will be two-thirds over.

"There is an intra-nasal vaccine that horse owners can administer," he said. "I'm encouraging all equid owners to vaccinate their animals as soon as possible."

But if the equid is showing symptoms, MacDougall says it's too late for the vaccination and the horseowner needs to get antibiotics to prevent the secondary bacterial infections.

The onset is of equine influenza is abrupt. with a fever up to 107.5 degrees. Normal is 99.5 to 100.5 degrees. The incubation period is usually one to three days, but up to seven days has been observed. Infected horses shed viruses during the incubation period and continue to excrete the virus for four to five days after clinical signs are observed.

"If your equid has yellow snot, they've got the flu," MacDougall said. "The symptoms are fever, coughing, nasal discharge, depression, muscle soreness, not eating and enlarged regional lymph nodes."

He added that nearly 20 percent of the infected horses do not exhibit clinical signs of disease, but still shed the virus and can spread the infection.

In the absence of secondary complications, healthy adult horses usually recover from equine flu within one to two weeks, however, coughing may persist for a longer period.

"Lots of people let their horse struggle through the flu, which makes me feel bad because no one likes to suffer with the flu," he said. "Vets are able to give the horse Banamine to break the fever and help the horse's appetite return."

Mortality of horses with confirmed infections has ranged from 1 percent to 20 percent and as high as 60 percent for animals who have never been exposed to influenza.

"Death has been reported as caused by secondary bacterial pneumonia and pleuritis," MacDougall said.

E-mail this story Printer-friendly version