Changes

==Introduction==

==Introduction==

 

Endocarditis is defined as an inflammation of one or more of the cardiac valves. It is usually a result of a bacteraemia or pyaemia, spread from adjaent myocardium is rare. It occurs in all species and is more common in cattle, pigs and sheep than dogs and cats.   

Endocarditis is defined as an inflammation of the cardiac endocardium.  The infection can affect the valves (valvular endocarditis) and then spread to the heart wall (mural endocarditis). It is usually a result of a bacteraemia or pyaemia, spread from adjaent myocardium is rare. It occurs in all species and is more common in cattle, pigs and sheep than dogs and cats.   

[[Image:Bacterial endocarditis.jpg|right|thumb|125px|<small><center>'''Bacterial endocarditis'''. Courtesy of A. Jefferies</center></small>]]

[[Image:Bacterial endocarditis.jpg|right|thumb|125px|<small><center>'''Bacterial endocarditis'''. Courtesy of A. Jefferies</center></small>]]

==Pathophysiology==

==Pathophysiology==

===Vegetative Endocarditis===

===Vegetative Endocarditis===

Predisposed by valvular damage as thrombi occur on the surface of the valves exposed to blood flow. Needs sustained or recurrent bacteraemia.  Some bacteria have particular adherence properties and may only need a single episode of bacteraemia to set up an endocarditis. Progression to rupture of the chordae tendinae is possible, along with spread of the infection to the adjacent mural endocardium. Valves may become stenotic, incompetant or both. Death usually results from either embolisation of the vegetative material or congestive heart failure due to significant valvular damage.

Predisposed by valvular damage as thrombi occur on the surface of the valves exposed to blood flow. Bacteremia is essential for the development of endocarditis.  Once bacteria colonize the valvular endocardium, vegetative lesions composed of platelets and fibrin are formed on the valves. Progression to rupture of the chordae tendinae is possible, along with spread of the infection to the adjacent mural endocardium. Valves may become stenotic, incompetant or both. Death usually results from either embolisation of the vegetative material or congestive heart failure due to significant valvular damage.

 

[[Image:vegetative endocarditis.jpg|right|thumb|125px|<small><center>'''Vegetative endocarditis (dog)'''. Courtesy of T. Scase</center></small>]]   

[[Image:vegetative endocarditis.jpg|right|thumb|125px|<small><center>'''Vegetative endocarditis (dog)'''. Courtesy of T. Scase</center></small>]]   

===UlcerativeEndocarditis===

===UlcerativeEndocarditis===

Commonly seen along with renal failure in dogs.Uraemia irritates and damages the endocarium, particularly in the left atrium.  Oedema is seen in the subendocardial tissue with deposition of glycosaminoglycans. This may progress to a necrotising endocarditis and, in extreme cases, left atrial rupture. If renal sufficieny is re-established then healing of the endocardial lesion is possible.

Commonly seen along with renal failure in dogs.Uraemia irritates and damages the endocarium, particularly in the left atrium.  Oedema is seen in the subendocardial tissue with deposition of glycosaminoglycans. This may progress to a necrotising endocarditis and, in extreme cases, left atrial rupture. If renal sufficieny is re-established then healing of the endocardial lesion is possible.

*Horse: Lesions occur mainly on the mitral valve. The site of sepsis is often not identified but may be a sequale to septic jugular thrombophlembitis.  

*Horse: Lesions occur mainly on the mitral valve. The site of sepsis is often not identified but may be a sequale to septic jugular thrombophlembitis.  

*Pig and dog: Lesions occur particularly on the mitral valve (71% of cases in dogs), perhaps due to the higher pressure blood flow on the left side of the heart leading to more valvular damage.  Left sided heart failure and pulmonary oedema are seen clinically, as are emboli in various organs, particularly the kidney.

*Pig and dog: Lesions occur particularly on the mitral valve (71% of cases in dogs), perhaps due to the higher pressure blood flow on the left side of the heart leading to more valvular damage.  Left sided heart failure and pulmonary oedema are seen clinically, as are emboli in various organs, particularly the kidney.

==Clinical Signs==

==Clinical Signs==

==Diagnosis==

==Diagnosis==

=from clinical=

=from clinical=

===Infective Endocarditis===   

===Infective Endocarditis===   

Horse: (uncommon); Males more affected

Horse: (uncommon); Males more affected