Guttural pouch tympany occurs when the guttural pouch (a pouch in the Eustachian tube that connects the ears to the nose and mouth and helps to regulate air pressure) becomes abnormally filled with air, causing nonpainful swelling just behind the jaw. The condition occurs in young horses (from birth to 1 year of age) and is more common in fillies than in colts. It may be caused by inflammation or by a congenital (present at birth) defect that allows air to enter the pouch but prevents it from returning to the pharynx.

Often, the swelling is the only noticeable sign; it may occur on one or both sides of the head. Other signs may include difficulty breathing, nasal discharge, and carrying the head in an extended position. The diagnosis is based on the signs and x‑rays of the skull.

Treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) and appropriate antibiotics is successful in most horses in which inflammation is the cause. If tympany is due to a congenital defect, surgery is required to provide a route for the air to be expelled from the affected guttural pouch. The outlook for recovery is good in most cases.

Last full review/revision July 2011 by Bonnie R. Rush, DVM, MS, DACVIM; Neil W. Dyer, DVM, MS, DACVP; Joe Hauptman, DVM, MS, DACVS; Ned F. Kuehn, DVM, MS, DACVIM; Stuart M. Taylor, PhD, BVMS, MRCVS, DECVP; Wendy E. Vaala, VMD, DACVIM; Maureen H. Milne, BVMS, MVM, DCHP, MRCVS