Southern Alberta horse owners are being advised to watch their animals for large lumps on their chests, following what are apparently the first-ever cases of pigeon fever in the province.
Pesky flies - Carriers of pigeon fever in horses
Southern Alberta horse owners are being advised to watch their animals for large lumps on their chests, following what are apparently the first-ever cases of pigeon fever in the province.
© 2013 by Carien Schippers
Pigeon fever is a disease common in the southern States and this year, veterinarians have seen about 20 horses infected with pigeon fever in Claresholm, Fort MacLeod, Lethbridge and Taber.
The most common form of the disease involves external abscesses that form deep in the muscles and can be very large, giving the horse the appearance of a pigeon breast.
Horses may become infected and yet not develop abscesses for quite some time. The disease usually occurs in younger horses, but can occur at any age and in any sex and breed.
Abscesses usually appear in the pectoral region, the ventral abdomen and the groin area, but can also occur along the back. They often rupture spontaneously and the wound exudes an ill-smelling, yellow and light tan-colored pus.
Functional problems can develop when abscesses are large and create pressure within the horse's muscles.
Ulcerative lymphangitis is the most common form worldwide and often involves one leg. Usually, multiple, small, draining sores develop above the fetlock.
When the disease is in the form of internal abscesses it is very difficult to diagnose and treat.
The disease is seasonal, with most cases occurring in the dry, hot months of early fall, when the fly population is at it height athough cases have occurred during the winter and at other times of the year.
The disease is contagious, but is not spread by horse-to-horse contact. Any fly that burrows in a horse's skin can be a carrier. The bacteria can infect other animals as well but there are different strains, so it's rare for cross-infection to occur.
There's no vaccine and no way to prevent pigeon fever. Antibiotics are useless in pigeon fever cases, since the drugs have no effect on the bacterium in the equine's body. If antibiotics are used before the abscesses drain completely, the infection can be prolonged and abscesses can develop internally.
About eight per cent of affected horses develop internal infections, and about 30 per cent of these horses die.
Fortunately, horses with external abscesses have a high survival rate.
Managing infection in horses with pigeon fever
Consistent and careful cleanliness wherever horses are kept, along with strong pest control measures for insects are very important. When an infected horse is on the premises, proper disinfection protocols should be utilized to limit the spread of the disease.
Gloves should be worn when handling infected horses. Any topsoil, bedding, mats, hay, straw or other material around an infected horse should be removed and replaced with clean soil or bedding.
Buckets or other containers used to collect pus from draining abscesses and any infectious material should be disposed of properly. All stalls, paddocks, utensils and tack should be thoroughly cleaned and disinfected.
Good sanitation practices should be followed, with thorough washing of hands and removal of clothing worn around infected horses, and any tools or implements used in the area, such as pitchforks or shovels, should be cleaned and disinfected.
Insect control measures should be carefully followed to limit flies and other pests.
Horses should be examined daily for wounds or abrasions that could become portals of entry for bacteria. Elective surgical procedures that require opening the skin should be scheduled for times when the disease is least likely to be active and when insect activity is at its lowest point.