[By Douglas Novick, DVM]
Pigeon Fever is a disease that seems to be unique to California and Texas. This disease causes abscesses to form. The bacteria involved is called Corynebacteria Pseudo tuberculosis. There are two reasons that it goes by the name Pigeon Fever. The first reason is that only five people in the United States can pronounce Corynebacteria Pseudo tuberculosis. The second reason stems from the behavior of the disease. Pigeon Fever tends to cause abscesses in the chest area of the horse. As the abscess develops the chest swells much like the prominent chest of a pigeon. Thus the name.
However, the chest is not the only place abscesses can form. Recent cases I have seen where abscesses form not in the chest but between the jaw bones and on one horse's sheath. It can also affect the mammary area in a mare. The disease starts with a firm diffuse swelling over the affected region. The hard swelling enlarges and then softens like a water balloon as the abscess comes to a head. At this point the abscess either pops by itself or is lanced by your veterinarian. It is not uncommon for affected horses to have a mild temperature of 102 to 103 degrees.
Veterinary treatment usually consist of hot packing the swelling until an abscess has formed at is ready to lance. Once the abscess is lanced the open wound is cleaned daily and your horse is put on antibiotics for an extended period of time. The problem with Pigeon fever is that it can cause multiple abscesses in a given horse. About one in five cases will have another abscess once the antibiotics are stopped. In very very rare cases a horse can even get an internal abscess which can result in peritonitis when it breaks open. At the first signs of swelling it is tempting to put your horse on antibiotics right away. However, doing so may increase the risk of internal abscesses forming. It is for this reason that most cases require waiting until the abscess has formed and been lanced before instituting antibiotic treatment.
There is no vaccination for Pigeon Fever. The bacteria is present throughout California and is spread by flies. It does follow a pattern of having one or two years when many horses in an area will get the disease. Then several years will follow without any cases being seen. This implies that horses in an area will develop a resistance on there own which gradually diminishes with time. Because it is spread by flies, on a given ranch if one horse becomes affected, it is likely that a small number of additional cases will be seen. However, unlike strangles, it is not likely that you will see more than a small percentage of horses on any one farm come down with the disease.
Dr. Douglas Novick is an equine veterinarian practicing in the San Francisco Bay Area. His practice is limited to the treatment of horses with special interests in equine lameness, equine dentistry and reproduction. He is also the first veterinarian in Northern California to implant horses with ID Microchips with optional freeze brands as a method of preventing horse theft.
See more at www.novickdvm.com
(C) 2004 Douglas Novick, DVM- This article is copyrighted. It is licensed for personal use only. Any re-use, duplication, re-transmission via electronic or other means without the expressed written permission of the author, Douglas Novick, is strictly forbidden.