Your horse is standing with his head down, drooling, and his food has barely been touched. He looks like he could be experiencing choke, but before you jump the gun it is important to realize that there could be more than one explanation. In fact, according to Danish veterinarians, there are more than 100 possible causes for dysphagia–the inability to swallow–in horses.

"Dysphagia is a relatively common disorder and can be either congenital or acquired; the definition of dysphagia involves difficulty in swallowing but often used more broadly to describe problems with eating," explained Julie Fjeldborg, DVM, PhD, associate professor in the Department of Large Animal Clinical Sciences, Faculty of Life Science at the University of Copenhagen, at the 12th Congress of The World Equine Veterinary Association, held Nov. 2-6 in Hyderabad, India.

Dysphagia encompasses problems associated with moving food into the mouth (prehension), chewing (mastication), and transporting the food down the esophagus, as well as problems actually associated with swallowing, Fjeldborg said.

According to Fjeldborg and colleague Keith Baptiste, BVMS, PhD, Dipl. ACVIM, ECEIM, also from the University of Copenhagen, dysphagia causes can be congenital (such as a cleft palate), acquired (including dental problems or drug-related side effects), or part of a multisystemic condition that could be associated with either a muscular or neurologic disease. Some examples of this latter category include equine protozoal myeloencephalitis, white muscle disease, and polysaccharide storage myopathy, among others.

"A thorough clinical examination is a must, bu