Changes

*Rare in other species  

*Rare in other species  

===Signalment===

==Signalment==

Typically in middle aged to older small breed dogs. Genetically predisposed breeds include Cavalier King Charles Spaniel, Bull Terriers, German Shepherds, and Great Danes.

Typically in middle aged to older small breed dogs. Genetically predisposed breeds include Cavalier King Charles Spaniel, Bull Terriers, German Shepherds, and Great Danes.

===Introduction===

==Introduction==

A congenital malformation or degeneration of the mitral valve leaflets and its supporting structures(chordae tendineae, papillary muscles, valvular leaflets, annulus) results in valvular regurgitation (insufficiency)  

A congenital malformation or degeneration of the mitral valve leaflets and its supporting structures(chordae tendineae, papillary muscles, valvular leaflets, annulus) results in valvular regurgitation (insufficiency)  

Chronic mitral regurgitation leads to volume overload of the left heart, which results in dilatation (eccentric hypertrophy) of the left ventricle and atrium. When mitral regurgitation is severe, cardiac output decreases, which results in signs of left sided cardiac failure [[LCHF]] and pulmonary venous congestion. Dilatation of the left-sided chambers predisposes affected animals to [[arrhythmias]]. In some cases, malformation of the mitral valve complex causes a degree of valvular stenosis as well as insufficiency.

Chronic mitral regurgitation leads to volume overload of the left heart, which results in dilatation (eccentric hypertrophy) of the left ventricle and atrium. When mitral regurgitation is severe, cardiac output decreases, which results in signs of left sided cardiac failure [[LCHF]] and pulmonary venous congestion. Dilatation of the left-sided chambers predisposes affected animals to [[arrhythmias]]. In some cases, malformation of the mitral valve complex causes a degree of valvular stenosis as well as insufficiency.

===Diagnosis===

==Diagnosis==

===History===

===History===

*Exercise Intolerance

*Exercise Intolerance

*Cough  

*Cough  

* Dyspnoea

* Dyspnoea

*Suden death due to left atrial tear and pulmonary oedema

*Sudden death due to left atrial tear and pulmonary oedema

===Clinical Signs===

===Clinical Signs===

* Left apical Systollic Murmur

* Left apical Systollic Murmur

* Left sided Congestive heart failure

* Left sided Congestive heart failure

**Pale Mucous membranes

**Pale Mucous membranes

** Prolonged Capillary refill time (CRT)

** Prolonged Capillary refill time (CRT)

** Pulmonary crackles / evidence of pulmonary oedema

** Pulmonary crackles / evidence of pulmonary oedema

** Cool extremities

** Cool extremities

** Loss of sinus tacchycardia

** Loss of sinus arrhythmia

** Cardiac arrhythmias e.g. Atrial fibrilation, Atrial premature complexes

** Cardiac arrhythmias e.g. Atrial fibrilation, Atrial premature complexes

===Diagnostic imaging===

===Diagnostic imaging===

* Pulmonary Oedema

* Pulmonary Oedema

Evidence of Right sided congestive heart failure maybe evident in severe cases e.g. distended caudal vena cava, hepatomegaly, ascites, pleural effusions.  

Evidence of Right sided congestive heart failure maybe evident in severe cases e.g. distended caudal vena cava, hepatomegaly, ascites, pleural effusions.  

===Laboratory Tests===

===Laboratory Tests===

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-Cough

 

-Tachypnea/Dyspnea

 

-Exercise Intolerance

 

-Syncope

 

-Pale Mucous Membranes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

==From Pathology==

==From Pathology==