Changes

Two types of hiatal hernia have been recognized in the dog and cat:

Two types of hiatal hernia have been recognized in the dog and cat:

*'''Sliding hiatal hernia''' - Cranial displacement of the distal oesophagus and stomach into mediastinum through the oesophageal hiatus.This is the most common form. It can occur in the dog and cat and may occur as a congenital or acquired lesion. The hernia results from incomplete fusion of the diaphragm during early embryonic development.

*'''Sliding hiatal hernia''' - Cranial displacement of the distal oesophagus and stomach into mediastinum through the oesophageal hiatus.This is the most common form. It can occur in the dog and cat and may occur as a congenital or acquired lesion. Congenital hernias result from incomplete fusion of the diaphragm during early embryonic development.

*'''Para-oesophageal hiatal hernia''' - Cranial displacement of part of the stomach into mediastinum through a defect ''adjacent'' to the oesophageal hiatus

Acquired hernias can occur in any breed of dog or cat. The cause is unknown but it is suspected to result from disorders that cause increases in intra-abdominal pressure (ie chronic vomiting) or increases in negative intrathoracic pressure (ie intermittent airway obstruction seen with laryngeal paralysis).

Sliding hiatal hernia ==Diagnosis==

==Diagnosis==

===Clinical Signs===

===Clinical Signs===

Depend on the severity and extent of the stricture but include:

Some animals may be asymptomatic but otherwise clinical signs include:

*Regurgitation shortly after feeding (may then attempt to re-ingest the regurgitant)

*regurgitation

*Anorexia

*vomiting

*Weight loss

*hypersalivation

*Malnutrition

*dyspnoea

*Ptyalism

*coughing

*Aspiration pneumonia (with associated pulmonary signs such as wheezing and crackling on lung auscultation)

*dehydration

*Liquid food better tolerated than solid food.

*weight loss

 

===Diagnostic Imaging===

===Diagnostic Imaging===

Fibrosing strictures must be differentiated from vascular ring anomalies, oesophagitis, intraluminal and extraluminal masses. This can be done with survey and contrast radiography, endoscopy and ultrasonography.

*'''Plain survey radiographs''' may visualise a caudodorsal gas-filled intrathoracic soft tissue opacity which is diagnostic of a hiatal hernia.Oesophageal dilatation and alveolar consolidation may be present with aspiration pneumonia.

 

*'''Barium contrast studies''' may be used to confirm a diagnosis.

Survey radiographs are usually unremarkable in animals with benign oesophageal strictures. Barium contrast radiography is normally diagnostic of the disorder and may demonstrate:

Intermittent hiatal hernias can be difficult to detect and therefore it is sometimes necessary to put pressure on the abdomen during the radiography procedure to induce displacement of the stomach.

*Segmental or diffuse narrowing of the oesophagus

 

Ultrasonography is not usually useful in diagnosing small benign strictures but may visualise those caused by mass compression.

 

Oesophagoscopy is used for a definitive diagnosis. It should be used to confirm the site and severity of the stricture and also to exclude the presence of an intraluminal mass.  

==Treatment==

==Treatment==