Megaesophagus and aspiration pneumonia secondary to gastric ulceration in a foal.

This research documents the case of a 3-month-old foal diagnosed with pneumonia, severe digestive system abnormalities and ulceration, leading to chronic gastroesophageal reflux, after presenting with persistent fever and increased white blood cell count. The horse was euthanized and its postmortem examination revealed these complications were likely the result of the severe gastric ulceration and the dilation of the distal portion of the esophagus.

Case Details and Diagnosis

• The article describes the clinical case of a 3-month-old foal presenting with a persistent fever and a high white blood cell count, known as leukocytosis. Upon examination, the foal was diagnosed with pneumonia, which is an inflammation of the lungs typically caused by infection.
• The foal also showed severe ulceration in the squamous part of its stomach, a condition that indicates open sores or lesions on the interior lining. There was also noted dilation of the distal portion of the esophagus. The esophagus is a muscular tube connecting the throat to the stomach, and dilation implies an abnormal enlargement or widening of this tube in its lower (distal) part – a condition known as megaesophagus.

Euthanasia and Necropsy Findings

• Due to the seriousness of the diagnosed conditions, the foal was euthanized. A post-mortem examination, or necropsy, was then conducted.
• The necropsy revealed a severely dilated distal section of the esophagus and seriously thickened stomach walls at the connection point with the esophagus (the cardia). Along with severe ulceration, these complications led the gastroesophageal junction to be permanently open, therefore allowing stomach contents to flow back into the esophagus – an issue known as gastroesophageal reflux.

Conclusion of the Research

• Finally, the researchers concluded that the noted megaesophagus and the pneumonia were likely secondary conditions resulting from the chronic gastroesophageal reflux.
• This necessary reflux was caused by the severe gastric ulceration and the mural thickening which kept the gastroesophageal junction open continuously, thus allowing the stomach’s acidic contents to flow back into and damage the lower esophagus.