External abscesses due to pigeon fever most commonly occur in the pectoral region and require surgical lancing to drain. | Photo: Kristen Slater

As pigeon fever spreads across the United States, so does information—and misinformation—about it.

As equine diseases spread geographically, fueled by changing climates and animal and vector movement, horse owners and veterinarians can no longer afford to ignore a disease, leaning on the excuse “we don’t see it around here.”

Corynebacterium pseudotuberculosis infection, commonly called “pigeon fever” or “dryland distemper,” is one of those conditions, once relegated to a handful of U.S. states and now making its way across North America. As a disease spreads, so does information—and misinformation—about it. In this article we will look at some common misconceptions about this condition.

Myth No. 1: Pigeons cause pigeon fever

Pigeon fever is not a valid excuse for mass bird extermination; the pigeon is falsely accused. Rather, the soil-inhabiting C. pseudotuberculosis produces a toxin called phospholipase D that causes the characteristic severe inflammation and local tissue damage infected horses exhibit