PIGEON BREAST: A Big Problem
By Kenton H. Arnold, DVM
Over the last few months we have seen a huge increase in the number of Pigeon Breast, or Pigeon Fever, cases at our clinic. Many of our clients have either experienced this nasty disease first hand or have seen a case in their barn or with a friend's horse. If you have been fortunate enough to not have seen Pigeon Breast first hand, it is still good to learn about the disease - just in case.
Pigeon Breast is caused by a soil borne bacteria called Corynebacterium pseudotuberculosis. It is not new to Texas, however, this last year it has reached an epidemic proportion as I have seen more than 30 cases in the last six months. Pigeon Breast is contagious, yet it is not as contagious as other common bacterial infections such as Strangles. The rise in infections appears to be due to the drought conditions that we have experienced over the last year.
The soil borne bacteria is picked up by flies and transmitted to the horse through fly activity on the animal. The bacteria incubates in the horse’s body, and typically manifest itself in the form of a large abscess on the chest which causes the chest to swell, resembling the pronounced breast of a pigeon. This is the reason for the name "Pigeon Breast". Occasionally the abscess will form in an alternative location. Over the last year I have had 3 cases where the abscess formed above the sheath in 2 geldings and a stallion. I have also seen several cases along the ventral mid-line of the belly and another case where the abscess busted just below the ear.
Most cases resolve well once the abscess is lanced and flushed, followed by antibiotic therapy. No one should ever start an affected horse on antibiotics before the abscess has ruptured or been lanced as this will prolong the length of the disease. Occasionally the abscess will form in a different location on the animal and could even be internal - such as in the spleen, kidney, liver or other internal lymph node. If an internal abscess occurs the disease quickly becomes life-threatening - most horses will die without aggressive treatment. Fortunately this is not common, especially with proper care and avoidance of antibiotics until after the abscess has ruptured or been lanced and flushed. Occasionally we did see a new abscess arise after the resolution of the first abscess. Monitoring for any new swelling is an important part of follow-up on any of these cases.
Although it is contagious, it is rare to see Pigeon Breast affect more than just a few horses on any one property. This rate is usually less than 10% of any population that has had a current case of Pigeon Breast, and with proper isolation and care the infection rate should be far lower. If a case is discovered it is best to let the veterinarian lance the abscess so that almost all of the infectious pus can be removed and disposed of properly. If the abscess ruptures on its own in the pasture, the amount of contamination to the environment is much higher, and depending on the amount of flies in the area the risk to the other horses can be much greater. Affected horses should be isolated until the draining abscess has dried up. Also any farrier work should be postponed on any horses with active draining abscesses; however other horses that have not yet formed a mature abscess pose little risk of spreading Pigeon Breast at that early stage of the disease.
Equine Veterinary Services