Primary esophageal obstruction in nursing foals – a retrospective analysis of 20 patients: clinical presentation, disease course and complications

Abstract

Esophageal obstruction is a commonly occurring disease in adult horses, however, the reported incidence in nursing foals is quite low. The aim of this retrospective study was to evaluate the medical records of 20 foals aged up to six months suffering from primary esophageal obstruction. We assessed clinical presentation, diagnostic procedures, therapeutic interventions, complications, as well as further investigations like passing of a nasogastric tube, endoscopy or radiology. The clinical course was tracked through owner phone calls up to six months after the foals were discharged. 5 of 20 foals were younger than one week old, 6 foals were between one and four weeks old, 3 foals between four and eight weeks and 6 foals were at the age of two and six months. The most common clinical signs were milky nasal discharge, coughing or snorting and rattling respiratory noises. On initial clinical pathology 5 of 20 foals had hemoconcentration, 12 demonstrated leukocytosis and 3 leukopenia. A roughage bolus was identified as the cause of the obstruction in all the examined foals. The roughage bolus was approximately 8 to 12cm aboral to the larynx. 9 (45%) of the foals received treatment under general anaesthesia, the esophageal obstruction was resolved either by passing a nasogastric tube or a flexible endoscope or by adequate water lavage. One of these foals required esophagotomy to remove the agglomerated, cigar-like bolus of roughage. In 8 of 20 (40%) of the affected foals, the obstruction was resolved under sedation either by passing a nasogastric tube or a flexible endoscope. No intervention was required in 3 of 20 (15%) affected foals. After resolution of the obstruction, endoscopy of the esophagus demonstrated that 33,3% of the examined foals had hyperemia, edema or superficial lesions of the esophageal mucous membrane at the site of the obstruction, while 40% of the foals had deep mucous membrane lesions or necrosis. In the further course of treatment, 4 of 20 (20%) foals developed aspiration bronchitis/ pneumonia. 30% of the foals developed one or more esophageal obstructions during the hospital stay or soon after discharge from the clinic. Two of these were euthanized at the owner's request, 16 and 17 days following initial admission due to significant stenosis formation. The foal that required esophagotomy developed left laryngeal paralysis, this was identified in routine endoscopy three years after surgery. But as the owner reported, this animal had experienced no clinical problem after discharge of the clinic. The findings of the 20 cases of esophageal obstruction in nursing foals indicate that the clinical signs are often mild and can resemble bronchitis. However, it represents an emergency situation and requires immediate treatment as complications such as dehydration, aspiration bronchitis and pressure necrosis occur in nursing foals more frequently compared to adult horses. The medical treatment in the standing patient is considerably more difficult in foals compared to adult horses, therefore general anaesthesia was more often necessary. PU - HIPPIATRIKA VERLAG MBH PI - STUTTGART PA - POSTFACH 102251, 70018 STUTTGART, GERMANY