Changes

*The disease is frequently asymptomatic.

*The disease is frequently asymptomatic.

*'''Gastro-intentinal signs''' may be reported, including vomiting, diarrhoea, abdominal pain, anorexia and weight loss.

*'''Gastro-intentinal signs''' may be reported, including vomiting, diarrhoea, abdominal pain, anorexia and weight loss.

*'''Respiratory distress''' may occur if abdominal contents occupy a large amount of volume of the thoracic cavity.

*'''Respiratory distress''' may occur if abdominal contents occupy a large amount of the thoracic cavity.

*'''Cardiac signs''' are unusual but cardiac tamponade (with right-sided heart failure) may develop if abdominal organs are incarcerated in the pericardial sac.  The heart sounds will be muffled on auscultation and borborygmi may be apparent.

*'''Cardiac signs''' are unusual but cardiac tamponade (with right-sided heart failure) may develop if abdominal organs are incarcerated in the pericardial sac.  The heart sounds will be muffled on auscultation and borborygmi may be apparent.  A heart murmur may be present if the animal has concurrent septal defects.

====Radiography====

====Radiography====

The cardiac silhouette is enlarged and continuous with that of the diaphragm.  If loops of small intestine have passed into the pericardial sac, areas of as lucency may be apparent overlying the cardiac silhouette and, if necessary, this can be confirmed by a barium contrast study.  The trachea may also be displaced dorsally.  

On plain radiographs of the chest, the cardiac silhouette is enlarged and continuous with that of the diaphragm.  If loops of small intestine have passed into the pericardial sac, areas of lucency may be apparent overlying the cardiac silhouette and, if necessary, this can be confirmed by a barium contrast study.  The trachea may also be displaced dorsally. In cats, an area of radio-opacity may be apparent in the area of the dorsal diaphragm on a lateral radiograph, referred to as the 'dorsal peritoneo-pericardial remnant.'

====Echocardiography====

====Echocardiography====

Definitive diagnosis generally relies on the identification of abdominal organs within the pericardial sac.

Definitive diagnosis generally relies on the identification of abdominal organs within the pericardial sac.  Septal defects may also be diagnosed during the scan.

===Treatment===

===Treatment===

If the animal is showing few clinical signs or if the hernia is discovered incidentally, '''conservative treatment''' may be all that is required.  In animals showing overt clinical signs, the abdominal organs can be retracted via a '''midline coeliotomy''' and the defect in the diaphragm can then be closed surgically.  This procedure may trap air within the pericardium so it is important to perform '''pericardiocentesis or pericardectomy''' before closure of the abdominal incision.  Even though organs may have been present in the pericardial sac for prolonged periods, it is rare for adhesions to form as these structures are in constant motion.  

If the animal is showing few clinical signs or if the hernia is discovered incidentally, '''conservative treatment''' may be all that is required.  In animals showing overt clinical signs, the abdominal organs can be retracted via a '''midline coeliotomy''' and the defect in the diaphragm can then be closed surgically.  This procedure may trap air within the pericardium so it is important not to close the pericardium and to perform '''pericardiocentesis''' before closure of the abdominal incision.  Even though organs may have been present in the pericardial sac for prolonged periods, it is rare for adhesions to form as these structures are in constant motion.  

===Prognosis===

===Prognosis===

A study assessing treatment regimes used in cats showed a post-operative mortality rate of 14%, whereas progressive disease was reported in 9% of those managed conservatively.  This result may largely reflect the criteria used for determining whether a cat was a surgical candidate.   

A study assessing treatment regimes used in cats showed a post-operative mortality rate of 14%, whereas progressive disease was reported in 9% of those managed conservatively.  This result may largely reflect the criteria used for determining whether a cat was a surgical candidate <ref>'''Reimer SB, Kyles AE, Filipowicz DE, Gregory CR''' Long-term outcome of cats treated conservatively or surgically for peritoneopericardial diaphragmatic hernia: 66 cases (1987-2002) ''J Am Vet Med Assoc. 2004 Mar 1;224(5):728-32''</ref>.   

===References===

===References===