Equine
Influenza: Protecting Your Horse
This summer has been filled with news of
problems caused by the avian influenza virus. Luckily, the influenza virus that
makes chickens sick does not spread to horses. However, its close cousin, the
equine influenza virus, does give horses “the flu”. Equine influenza affects
the airways and causes horses to suffer with a fever, poor appetite and runny
nose. Horses with the flu usually feel
sick for one to two weeks before recovering. The damage caused to the airways
by equine influenza virus results in a cough that may last up to three months
and seriously hinder training or competition.
The flu is highly contagious and is
spread through contact, buckets, tack, and on peoples skin and clothing. Once
one animal catches the flu, it rapidly spreads throughout the barn to other
unvaccinated horses. Young horses, very
old horses or stressed horses are most likely to become sick with the flu.
Horses that go to the racetrack and those that go out for breaking, training or
showing are most likely to suffer from the flu and bring it home to
stablemates.
Traditionally, we have used an injectable
vaccine given every 4 months to try to prevent equine influenza. However, in
the 1990’s, research at the Western College of Veterinary Medicine proved that
vaccinated horses were getting sick with the flu. This led to the development
of new, more effective vaccines. In Canada, there are two licensed vaccines
that have been proven to protect horses against the flu for at least six months
after vaccination.
FluAvert IN has been shown
to provide excellent protection against influenza. It is designed to be
administered intranasally by a veterinarian and stimulates the immune system in the airways to produce antibodies
against the influenza virus. When a horse is exposed naturally, the immune
system reacts quickly and prevents the virus from setting up an infection and
causing disease. Fluavert is
designed to be given every six months.
Calvenza is the newest
vaccine available against influenza. Calvenza is a dual vaccine against
influenza and rhino (equine herpes virus 1). It has been shown to provide
excellent protection against the flu, but has only been shown to provide three
weeks protection against rhino.
Initially, two vaccines are administered three weeks apart, then a
single vaccination is given every 6 to 9 months to provide ongoing protection
against influenza. Calvenza can be given to pregnant mares 1 month
before foaling to provide high antibody levels against influenza in colostrum,
protecting foals for the first six months of life.
If you are interested in developing an up
to date vaccination program for your horses, or to book an appointment for to
vaccinate your horse against “the flu” please contact the clinic.