Impaction of the Oesophagus

Also known as:

Choke

Description

Impaction/obstruction of the oesophagus or 'choke' is the most common oesophageal disease of cattle and horses. The most common sites of obstruction are the thoracic inlet, the base of the heart, and the hiatus oesophagus of the diaphragm. In horses, causes of choke include consumption of unsoaked sugarbeet, rapid ingestion of roughage (hay), indadequate mastication of food, or rarely the ingestion of a foreign body (e.g. corn cob). Horses that are poorly fed or have poor dentition are more prone to the condition.

Clinical Signs

Horse

Although the presentation of a horse with choke may be dramatic, it does not constitute an emergency. The typical sign of choke is dysphagia with regurgitation of food and saliva through the nostrils. Acute onset pain may manifest through alterations in posture such as an arched neck or abducted elbows. The horse may appear anxious, grunt frequently and make repeated attempts to swallow. If the obstruction has led to the accumulation of food material in the oesophagus, a mass may be palpable on the left ventrolateral aspect of the neck. If the condition has become long-standing, foetid breath may be apparent. If accompanied by pyrexia, this may indicate the development of aspiration pneumonia.

Cattle

Impaction of a bovine oesophagus (Courtesy of Alun Williams (RVC))

Oesophageal obstruction in cattle is a more serious condition than in the horse. Obstruction of the oesophagus leads to failure of eructation of gases from the rumen, which may lead to bloat.

• May eat a spherical object that obstructs the oesophagus mostly in anterior 1/3rd of oesophagus and can often be palpated in live animal.
• Potatoes can be a cheap source of feed and if fed whole can become stuck in oesophagus.
• If obstruction occurs further down can be difficult to diagnose and remove.
• Cattle develop bloat when oesophagus obstructed.
• Apples fairly easily to dislodge.

Dog

• Usually with small bones
• Animals that feel protective of feed may gulp food down quickly, particularly if given small chops / knuckle bones.
• Knobbly shape may make bone lodge in oesophagus, particularly just anterior to heart.
• Very difficult to dislodge (because of shape).
• Pressure necrosis occurs very quickly around it and can erode through oesophagus within about 24 hours.
• Small bone may also lodge in duodenum if they pass through the stomach.