2. DISEASES OF THE CARDIOVASCULAR SYSTEM

3. CANINE DILATED CARDIOMYOPATHY
90% of cases occur in Doberman Pinschers and Boxers
OTHER BREEDS INCLUDE WOLFHOUNDS, GREAT DANES, AND COCKER SPANIELS

4. THE WALLS OF THE HEART ARE WEAK, FLABBY, AND DILATED

5. CANINE DILATED CARDIOMYOPATHY: PATHOPHYSIOLOGY
DECREASED CONTRACTILITY from an unknown cause (viral?, carnitine deficiency?)
Decreased contractility = decreased overall cardiac output
CO (CARDIAC OUTPUT) = SV (STROKE VOLUME) X HR (HEART RATE)
Squeezing a water bottle analogy
Amt. of blood ejected with
Each cardiac contraction
(affected by afterload, preload,
and inherent contractility)
How often the heart
contracts
The amt. of blood that leaves
The heart in a given unit of time

6. CANINE DILATED CARDIOMYOPATHY: PATHOPHYSIOLOGY
THE BODY COMPENSATES BY:
1. INCREASING THE HEART RATE
*this is done by sympathetic nervous system stimulation
2. TRYING TO INCREASE STROKE VOLUME BY INCREASING PRELOAD (this means that the body increases filling of the heart)
*This is done by retaining sodium and water

7. CANINE DILATED CARDIOMYOPATHY: CLINICAL SIGNS
LETHARGY, EXERCISE INTOLERANCE, COUGHING, TACHYPNEA,
SYNCOPE, SOFT MURMUR, PLEURAL EFFUSION, ASCITES, HEPATOMEGALY

8. Normal Echocardiogram

9. Canine Dilated Cardiomyopathy Echocardiogram

10. CANINE DILATED CARDIOMYOPATHY: ECHOCARDIOGRAM
PERFORMING AN ECHOCARDIOGRAM
IS THE DEFINITIVE WAY TO DIAGNOSE
DILATED CARDIOMYOPATHY

11. CANINE DILATED CARDIOMYOPATHY
Enlarged, round heart

12. CANINE DILATED CARDIOMYOPATHY
PLEURAL EFFUSION
PULMONARY EDEMA
PATIENT MAY SHOW SIGNS OF LEFT-SIDED, RIGHT-SIDED, OR HEART FAILURE FROM BOTH SIDES

13. PULMONARY EDEMA VS PLEURAL EFFUSION
Pulmonary edema is the accumulation of fluid in the ALVEOLI of the lungs
Causes dyspnea due to air being displaced by fluid
Left sided heart failure
Pleural effusion is the accumulation of fluid in the pleural space OUTSIDE of the lungs
Causes dyspnea due to lungs not being able to expand fully
Right-sided and congestive heart failure

14. CANINE DILATED CARDIOMYOPATHY: PATHOPHYSIOLOGY
Constant stimulation of the heart by the sympathetic nervous system causes ventricular arrhythmias and myocyte death
Most common arrhythmias: VPC’s and ventricular tachycardia, esp. in boxers & Dobies; other dogs may have APC’s and atrial fibrillation
ONE VPC
MULTIPLE VPCs
CAUSING TACHY-CARDIA

15. CANINE DILATED CARDIOMYOPATHY: DIAGNOSTICS
Laboratory tests
Atrial Natriuretic peptide increase
Released from atria in response to excess stretch
Brain natriuretic peptide increase
released from ventricles in response to excess stretch
Pro-BNP release
Troponin 1 (cTn1) increased
Released when heart muscle is damaged

16. CANINE DILATED CARDIOMYOPATHY: TREATMENT
INCREASES CONTRACTILITY
DIGOXIN
FUROSEMIDE
REDUCES FLUID
RETENTION
ENALAPRIL
DIURETIC-ELIMINATES EXCESS
FLUID

17. CANINE DILATED CARDIOMYOPATHY: TREATMENT
L-CARNITINE
COENZYME Q10
TAURINE – USED IN COCKER
SPANIELS AND CATS, MAINLY
DIETARY SUPPLEMENTS THAT MAY HELP IMPROVE HEART FUNCTION, ESP
IF THERE IS A DEFICIENCY

18. CANINE DILATED CARDIOMYOPATHY: CLIENT INFO
DCM is a progressive diseases that is almost always fatal
Most dogs die within 6 months -2 years
Death may occur suddenly due to arrhythmias

19. FELINE DILATED CARDIOMYOPATHY
A globular-shaped heart with
severe dilation of all four
chambers. Depressed
ventricular contractile
performance occurs.
Ventricular dilation distorts the
atrioventricular valves leading to
mitral regurgitation and atrial
enlargement
ABNORMALLY THIN VENTRICULAR WALLS

20. FELINE DILATED CARDIOMYOPATHY
In the 1980’s DCM in cats was one of the most commonly diagnosed heart diseases. It was discovered that this was caused by a deficiency of TAURINE, an amino acid.
Since that time commercial foods have added taurine to feline diets, which has significantly decreased the number of cases of feline DCM