Veterinarians in Germany have described their successful treatment of a one-month-old miniature Shetland pony with a life-threatening restriction in his esophagus.
Pieter Nijdam, Colette Elmas and Maria Fugazzola have described their treatment of the little colt, weighing just 14kg, in a report published in the journal Case Reports in Veterinary Medicine.
The treatment involved surgery and the later use of balloon dilation, showing that the two techniques could be successfully combined.
The youngster was taken to the Burg Müggenhausen Equine Clinic for emergency treatment. He was weak, was regurgitating milk, and had a white discharge from both nostrils.
An endoscopic examination of the esophagus and an X-ray led to the diagnosis of an esophageal stricture and aspiration pneumonia.
An esophageal stricture is a narrowing of the lumen of the esophagus. They usually form as a result of external or internal trauma to the esophageal wall. Congenital esophageal strictures, though rare, have also been documented.
They usually lead to impaired passage of food. Nasal discharge, salivation, coughing, discomfort and extension of the head and neck may also occur. Aspiration pneumonia is a common complication.
Esophageal surgery is technically demanding and often associated with complications. Overall, the prognosis is guarded.
The narrowing of the esophageal lumen in this case was visible at the second cervical vertebra. The esophagus narrowed from 9.5mm to 5mm at the stricture.
The foal underwent surgery, in which an esophagomyotomy was performed to open up the stricture. Afterwards, for recovery, the foal was only allowed to nurse. Solid feed was withheld by use of a muzzle.
No regurgitation of milk or nasal discharge was seen after surgery. The foal was discharged from the hospital with instructions to gradually reintroduce the foal to solid food after two weeks.
Forty days after discharge the foal was returned to the clinic as he was regurgitating food again. He was attentive, had gained 6 kilograms, and had satisfactory body condition.
An examination revealed no abnormalities. The incision had healed without complications. However, nasogastric tubing found resistance at the same location as before and X-rays confirmed persistence of the stricture.
“As the esophageal stricture had not improved sufficiently, treatment by balloon dilation was initiated,” the veterinarians reported.
They used a 24cm long balloon catheter, put in position by advancing it through the working canal of the endoscope. During three separate sessions with 10-day intervals, the stricture was dilated twice for 30 seconds after which the balloon catheter was removed.
Over the three sessions, the pressure and thus diameter of the balloon were gradually increased from 10mm up to 20mm.
Each time, the stricture was checked by endoscope for possible swelling and scarring. It was treated with topical dexamethasone to reduce possible swelling and scarring of the esophageal wall.
Two days after the second balloon dilation, the foal was returned to the clinic with a fever and apathy. He was not eating, and his heart rate and respiration rate were fast. There was non-painful swelling on the side of the neck.
The most likely explanation was transient inflammation of the dilation site with possible short-term infection. It was quickly resolved with antibiotics and anti-inflammatory drugs.
After the third dilation, the foal was increasingly allowed to eat solid food, mostly grass and hay, over the course of two weeks.
The foal did not have any complaints for up to 12 months after the final treatment. Endoscopic and ultrasonographic examination at that time showed no apparent abnormalities. The diameter at the stricture site had increased from 5mm to 10.9mm, as assessed by ultrasound.
The veterinarians said previous research had found a survival rate of 22% in non-surgically managed esophageal strictures and 46% in surgically managed cases. Balloon dilation of esophageal strictures has been described in literature, mainly in case reports.
“To our knowledge, this is the first report describing this abnormality in a miniature Shetland foal,” Nijdam and his colleagues reported.
“The combination of both surgical intervention and balloon dilation also has not been described previously.
“This case report shows that if surgical treatment for esophageal stricture is elected but shows recurrence of the problem, balloon dilation may still be performed successfully afterwards.”
Treatment of an Esophageal Stricture in a 1-Month-Old Miniature Shetland Colt
P. Nijdam, C. Elmas, and M. C. Fugazzola
Case Reports in Veterinary Medicine, Volume 2017, Article ID 3069419