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===Description===

===Description===

Impaction/obstruction of the oesophagus or 'choke' is the most common oesophageal disease of cattle and horses. Obstruction usuually occurs at the thoracic inlet, the base of the heart or the hiatus oesophagus of the diaphragm (i.e. the narrowest points). 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.  

Impaction/obstruction of the oesophagus or 'choke' is the most common oesophageal disease of cattle and horses. Obstruction usuually occurs at the level of the thoracic inlet, the base of the heart or the hiatus oesophagus of the diaphragm (i.e. the narrowest points). 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 developing the condition.  

In cattle, choke usually occurs due to the ingestion of a single solid vegetable or fruit such as a potato, turnip or corn cob.  

In cattle, choke usually occurs due to the ingestion of a single solid vegetable or fruit such as a potato, turnip or corn cob.  

===Clinical Signs===

===Clinical Signs===

===Diagnosis===

===Diagnosis===

An initial diagnosis of choke in any animal may be suspected if the above clinical signs are present with a history of acute onset pain and access to unsuitable food. 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 although this may be difficult to detect in the adult cow. Confirmation of the diagnosis may be achieved by the inability to pass a nasogastric tube or direct visualisation of the obstruction using endoscopy.

An initial diagnosis of choke in any animal may be suspected if the above clinical signs are present with a history of acute onset pain and access to unsuitable food. 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 although this may be difficult to detect in the adult cow. Confirmation of the diagnosis may be achieved by the inability to pass a nasogastric tube or direct visualisation of the obstruction using endoscopy. Other tests that may provide useful information include radiography and ultrasound.

===Treatment===

===Treatment===

In the horse, treatment is usually conservative as most obstructions resolve spontaneously or with medical treatment. Treatment comprises the use of sedatives to calm the horse and spasmolytics to reduce oesophageal muscle spasm. If conservative treatment fails to resolve the problem, oesophageal lavage may be attempted. Due to the risk of aspiration, lavage is only used in horses where medical management was unsuccessful.

In the horse, treatment is usually conservative as most obstructions resolve spontaneously or with medical treatment. Treatment comprises the passage of a nasogastric tube followed by intraluminal oesophageal lavage. Before attempting this procedure it is important to ensure that the horse is well sedated (with its head below the thoracic inlet) so that the risk of aspiration is minimised. The administration of oxytocin may be beneficial, particularly in animals with cranial onstructions. If conservative treatment fails to resolve the problem, oesophageal lavage may be attempted. Due to the risk of aspiration, lavage is only used in horses where medical management was unsuccessful.

In cattle, rumenal bloat caused by the obstruction is an emergency and requires immediate treatment. This is achieved by trocharisation through the left paralumbar fossa. Once the bloat has been relieved, the obstruction may be manually broken down via percutaneous massage, or may resolve spontaneously due to the large volume of saliva present.

In cattle, rumenal bloat caused by the obstruction is an emergency and requires immediate treatment. This is achieved by trocharisation through the left paralumbar fossa. Once the bloat has been relieved, the obstruction may be manually broken down via percutaneous massage, or may resolve spontaneously due to the large volume of saliva present. As in the horse, a sedative such as xylazine may be administered combined to provide both sedation and muscle relaxation. Broad spectrum antibiotics should be administered if there is any suspicion of aspiration,

===Prognosis===

===Prognosis===