Changes

==Description==

==Description==

Transudates are a type of [[:Category:Effusions|effusion]] that has a low cellularity and a low protein content.  Transudates occur due to imbalances in the Starling forces, of which the two principal examples are hydrostatic pressure and plasma oncotic pressure (or colloid osmotic pressure).  The following causes of transudate effusions are therefore recognised:

Transudates are a type of [[:Category:Effusions|effusion]] that has a low cellularity and a low protein content.  Transudates occur due to imbalances in the '''Starling forces''', of which the two principal examples are hydrostatic pressure and plasma oncotic pressure (or colloid osmotic pressure).  The following causes of transudate effusions are therefore recognised:

*'''Reduced plasma oncotic pressure''' may occur if plasma proteins are lost.  Albumin contributes 75% of the total oncotic pressure so [[Hypoalbuminaemia|'''hypoalbuminaemia''']] is the major cause of transudate effusions.

*'''Reduced plasma oncotic pressure''' may occur if plasma proteins are lost.  Albumin contributes 75% of the total oncotic pressure so [[Hypoalbuminaemia|'''hypoalbuminaemia''']] is the major cause of transudate effusions.

*'''Increased hydrostatic pressure''' may occur with inappropriate activation of the renin-angiotensin-aldosterone system (RAAS), as in congestive heart failure and portal hypertension.  Both diseases commonly result in high-volume ascites, although this is often composed of a modified transudate.

*'''Increased hydrostatic pressure''' may occur with inappropriate activation of the renin-angiotensin-aldosterone system (RAAS), as in congestive heart failure and portal hypertension.  Both diseases commonly result in high-volume ascites, although this is more often composed of a [[Modified Transudate|modified transudate]].

==Diagnosis==

==Diagnosis==

===Clinical Signs===

===Clinical Signs===

Effusions may occur in any of the major body cavities, causing:

Effusions may occur in any of the major body cavities, causing ascites, hydrothorax or pericardial effusion.  '''Ascites''' is often of a high volume.  An abdominal fluid thrill will often be palpable and the abdomen may appear to be grossly swollen.

*'''Ascites''', often of a high volume.  An abdominal fluid thrill will often be palpable and the abdomen may appear to be grossly swollen.

 

*'''Hydrothorax''' causing tachypnoea and dyspnoea if severe.  Dullness will be evident on thoracic percussion if a pleural effusion has developed and the heart sounds will be muffled on auscultation.

'''Hydrothorax''' will cause coughing, tachypnoea and dyspnoea if severe.  Dullness will be evident on thoracic percussion if a pleural effusion has developed and the heart sounds will be muffled on auscultation.

*'''Pericardial effusion''', which may be sufficiently severe to cause cardiac tamponade and right-sided heart failure.  The heart sounds will be muffled on auscultation and there may be hepatojugular reflux, a jugular pulse or signs of left-sided forward failure.

 

*In large animals (horses and cattle), it is much more likely that '''ventral oedema''' will be observed in animals with liver failure (causing hypoalbuminaemia) or congestive heart failure.

'''Pericardial effusion''' may be sufficiently severe to cause cardiac tamponade and right-sided heart failure.  The heart sounds will be muffled on auscultation and there may be hepatojugular reflux, a jugular pulse or signs of left-sided forward failure. In horses and cattle, it is much more likely that '''ventral oedema''' will be observed in animals with liver failure (causing hypoalbuminaemia) or congestive heart failure.

===Diagnostic Imaging===   

===Diagnostic Imaging===   

[[Category:To_Do_-_James]]

[[Category:To_Do_-_James]]

[[Category:Horse]][[Category:Cat]][[Category:Dog]][[Category:Cattle]]

[[Category:Horse]][[Category:Cat]][[Category:Dog]][[Category:Cattle]]