Boehringer Ingelheim Vetmedica Inc. (BIVI) has placed a voluntary stop sale on its conditionally licensed Corynebacterium pseudotuberculosis bacterin-toxoid vaccine, more commonly known as the "pigeon fever vaccine."

A written statement from the company said the voluntary stop sale, which took effect April 9, "is due to reports of unexpected post-vaccination gastrointestinal tract events observed in some horses. During the required pre-licensing safety studies, these events were not observed.

"We are committed to supplying the highest quality products to our customers and believe a voluntary stop sale is in the best interest of our customers and their horses," the company’s statement said.

The statement indicated that an investigation into these events is underway