DISEASES OF THE CARDIOVASCULAR SYSTEM CANINE DILATED CARDIOMYOPATHY

DISEASES OF THE CARDIOVASCULAR SYSTEM

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

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

CANINE DILATED CARDIOMYOPATHY: PATHOPHYSIOLOGY l 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) The amt. of blood that leaves The heart in a given unit of time Amt. of blood ejected with Each cardiac contraction (affected by afterload, preload, and inherent contractility) How often the heart contracts

CANINE DILATED CARDIOMYOPATHY: PATHOPHYSIOLOGY l 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

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

Normal Echocardiogram

Canine Dilated Cardiomyopathy Echocardiogram

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

CANINE DILATED CARDIOMYOPATHY Enlarged, round heart

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

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

CANINE DILATED CARDIOMYOPATHY: PATHOPHYSIOLOGY l 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

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

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

CANINE DILATED CARDIOMYOPATHY: TREATMENT COENZYME Q 10 TAURINE – USED IN COCKER SPANIELS AND CATS, MAINLY L-CARNITINE DIETARY SUPPLEMENTS THAT MAY HELP IMPROVE HEART FUNCTION, ESP IF THERE IS A DEFICIENCY

CANINE DILATED CARDIOMYOPATHY: CLIENT INFO l 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

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

FELINE DILATED CARDIOMYOPATHY l 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. l Since that time commercial foods have added taurine to feline diets, which has significantly decreased the number of cases of feline DCM