You wake up after having a fitful night, coughing, wheezing, and constantly grabbing for that next tissue. Your chest feels like its in a vice, you can't eat and you've got the blues. What you've really got is the flu, and when your horse has it, he doesn't feel much better. With the many major horse shows and competitions taking place in this country, the likelihood your horse will contract the flu, if you're one of those traveling, is a fairly good one.
Influenza is a virus and is highly contagious in horses.
In horses, the virus is caused by two distinct strains of influenza virus A. Symptoms include inflammation of the nasal passages and throat, fever, coughing, wheezing, lack of appetite, and depression. Because it is a virus, there is little that can be done to cure it, other than to treat the symptoms and increase the comfort level of its victim. However, when your horse also happens to be a competition animal and an excellent athlete, it's also difficult to wait for a flu to run its course. Influenza virus infections are common among young horses in training and outbreaks of the virus occur at least annually in most horse populations. In a study conducted at The Ohio State University, under guidelines of the OSU animal care and use committee, to determine the effects of exercise on horses infected with influenza, as compared with infected horses given stall rest, it was concluded that while the exercised horses did not have the virus any longer than those given stall rest, the symptoms were definitely exacerbated by exercise.