In a case report from a research project done at the College of Veterinary Medicine at Iowa State University, esophageal perforation within the thorax (chest) of 5 horses was examined. While perforation of the esophagus “is an uncommon event that can occur for a variety of reasons,” the location where the esophagus has been compromised plays a role in the prognosis. Intrathoracic rupture (within the chest cavity) of the esophagus carries a grave prognosis, can occur spontaneously, may have no history of obstruction (“choke”), and may not be discovered until a secondary pleuropneumonia (inflammation of the tissue that lines the lungs and the chest cavity along with pneumonia) has developed.
This study looked at 5 cases, including a 15-year-old Friesian mare. The mare was presented to Iowa State five days after transport from Pennsylvania to Iowa. Her medical history was uncertain, but she had not “choked” during transport. Upon examination, she had a fever, was depressed, and not eating. Her heart and respiratory rates were elevated, an ultrasound revealed fluid in her chest, and her blood work was abnormal. Chest tubes were placed, and fluid was drained off both sides of her chest. She was treated aggressively but continued to deteriorate. Plant material, consistent with hay, was found in the fluid that was drained off the right side of her chest, and the possibility of a rupture of the esophagus was raised. Despite a grave prognosis, the mare was taken to surgery, where a 6.35 cm tear was found in the esophagus along with caudal muscular hypertrophy (increased thickness of the muscular layer of the esophagus). The mare was humanely euthanized on the surgery table. Some of the conclusions reached by this group are as follows:
Spontaneous rupture of the intrathoracic esophagus may be more common that we think.
Friesians have a suspected genetic inheritance of megaesophagus.
Megaesophagus has been associated with spontaneous rupture of the esophagus.
Horses with megaesophagus may present with non-specific signs, requiring more advanced diagnostics.
The mortality rate of those horses with intrathoracic esophageal rupture is exceedingly high.
While megaesophagus is infrequently encountered in clinical practice, pleuropneumonia secondary to esophageal perforation can present with nonspecific clinical signs and should be considered in cases of pleuropneumonia without an obvious underlying cause.
Scientific Article: Hepworth-Warren, KL et. al. “Intrathoracic oesophageal perforation and secondary pleuropneumonia: Five cases” EVE June 2015, pp. 283-290.