Foals with Milk Dripping from NostrilsBy Dr. Bryan Waldridge · May 16, 2012
Foals rarely have difficulty swallowing. Milk observed draining from one or both nostrils is a sign of difficulty swallowing (dysphagia). Some causes of throat and/or palate dysfunction in foals can be serious and detrimental to life. The most important condition to rule out is a cleft palate, which usually involves the soft palate in the back of the throat, but the palate can be cleft into the hard palate between the teeth. Difficulty swallowing puts foals at high risk for aspiration pneumonia when feed material, saliva, and oral bacteria can drain into the trachea and lungs. Aspiration pneumonia can be serious and life-threatening.
Other rule outs for dysphagia in foals include selenium or vitamin E deficiency, hyperkalemic periodic paralysis (HPP; especially homozygous foals), and botulism. Many muscles and nerves are involved to coordinate the complex movements of swallowing and these muscles are at constant work during swallowing and breathing. Selenium and vitamin E deficiency can result in muscle damage and weakness that can also involve the skeletal and cardiac muscles. Foals affected with HPP have muscle weakness during attacks and their signs of upper airway dysfunction are most noticeable when they are stressed or restrained. Botulism causes weakness (shaker foal syndrome) and difficulty swallowing or eating can be the first clinical sign observed.
Holcombe and others reviewed 16 cases of dysphagia in foals with presumed throat problems. Affected foals represented a variety of breeds and only one was premature. Seventy-five percent of foals had aspiration pneumonia and 38% of foals had signs of hypoxic-ischemic encephalopathy (dummy foals). Treatments varied but included antibiotics, anti-inflammatory drugs, muzzling, or placing nasogastric feeding tubes. In 75% of foals, endoscopy revealed that the foal’s throat was weak, flaccid, collapsed, and inflamed. Three foals had persistent or frequent displacement of their soft palate. Ninety-four percent of foals were eventually discharged from the hospital and all but one no longer had any signs of dysphagia. Follow-up information (1-5 years after the foals were discharged from the hospital) revealed that 81% of foals were still alive and half of the affected foals were in active athletic work.
Dysphagia in foals is not common, but it is an important problem in neonatal foals. Selective breeding (HPP) and recognition, treatment, and prevention of vitamin E and selenium deficiency will help to reduce the odds that a foal may be affected.
Holcombe S.J., S.D. Hurcombe, B.S. Barr, H.C. Schott II. 2012. Dysphagia associated with presumed pharyngeal dysfunction in 16 neonatal foals. Equine Veterinary Journal Supplement 44:105-108.