We in Alberta have been issued a health alert for pigeon fever in horses. More than 10 horses in Southern Alberta have been diagnosed with this fever this fall.
So what the heck is pigeon fever? It is a nasty infection caused by the bacterial organism Corynebacterium pseudotuberculosis (also call dryland distemper). This bacteria tends to localize and form abscesses in the pectoral (chest) region and ventral abdomen. It shows up as swellings that look like a pigeon’s breast (hence the name). This infection can also affect sheep, goats and cattle.
The bacteria tends to live and multiply in dry soil and manure. Horses can contract this infection through open wounds, mucous membranes or flies. Flies transmit the bacteria into horses when flies bite the horses. Horses will develop a fever and the abscesses.
Once the abscesses mature, they can be lanced, drained and regularly flushed while healing. During this process, pain medications can be administered to make the horse more comfortable. These swellings can appear on one or both sides of the chest, on the belly, neck and head. In some cases (eight per cent), internal abscesses can occur and, in some cases, they can be fatal (Barb Glen, Lethbridge Bureau, Western Producer).
Following are the clinical signs of pigeon fever as identified by Jessie Evans DVM — American Association of Equine Practitioners: “You will know if your horse is infected by swelling of the chest or abdomen. The horse might have a fever (temperature greater than 101.5 F) but he usually exhibits a normal attitude and appetite. An affected animal might be sore at the walk, usually after swelling and abscess of his chest and abdomen have occurred. Some develop more severe infections where they acquire multiple abscesses and become systemically ill. A small percentage of horses can develop internal abscesses which are more serious.”
So what can we do to prevent further outbreaks? If you have a horse that is affected, that horse needs to be isolated from all other horses. The drainage from the abscesses will contain a large amount of the bacteria, which will contaminate the environment. Since flies are the major method of transmission, all attempts must be made to reduce fly populations (spraying, fly traps) and to minimize exposure of other affected or non-affected horses. As the horse handler, you must also be aware that you can carry the bacteria on your boots, hands and clothing. In fact, any materials that come in contact with the sick horse can carry the bacteria. You should follow strict hygiene practices to prevent transmission to other animals. Everything needs to be disinfected and/or disposed of and not shared with other horses. This includes water buckets, bedding, blankets and halters.
This warning is a wake-up call for all horse owners – we must always pay attention to our horses and watch for any changes that might be signs of bad things happening.
