Camelidae and Cervidae Berserk Male Syndrome – NAVLE Study Guide

Overview and Clinical Importance

Berserk Male Syndrome (BMS), also known as Aberrant Behavior Syndrome (ABS) or Berserk Llama Syndrome (BLS), is a serious behavioral disorder primarily affecting human-raised camelids (llamas and alpacas) and can occur in cervids (deer) that have been hand-reared. This condition results from improper imprinting during early development, causing affected animals to perceive humans as conspecifics and exhibit dangerous aggressive and dominance behaviors.

The syndrome was first documented in the 1970s following the importation of llamas to the United States. Understanding this condition is critical for veterinarians as it represents a significant welfare and safety concern. Affected animals often cause serious injuries to handlers and frequently require euthanasia when behavioral modification fails.

Etiology and Pathophysiology

The Imprinting Process

Imprinting is a rapid learning process that occurs during a specific developmental window (critical period) in which young animals form strong attachments and learn species-typical social behaviors. In camelids, this critical period extends through the first several weeks of life, during which crias normally bond with their dams and learn appropriate camelid social behaviors.