Canine Cardiomyopathy

Type of cardiomyopathy commonly seen in Boxers

Familial arrhythmogenic cardiomyopathy

Definition for DCM

A primary myocardial disease characterized by cardiac enlargement and impaired systolic function

Most common breeds prone to developing DCM

Large breeds: Doberman, Great Dane, Irish Wolfhound, St. Bernard, Newfoundland, Leonberger, Boxer, Giant Schnauzer, Cocker Spaniel, Flat Coat Retriever

Early clinical signs for DCM

-fatigue, lethargy, exercise intolerance

-dogs can be asymptomatic until they suddenly have symptoms associated with heart failure

Signs of heart failure

-respiratory distress from left sided heart failure

-abdominal distension from ascites from right sided congestive heart failure

Diagnostics for DCM

-echocardiography: perform based on presence of clinical signs, auscultation, and radiographic findings

-echocardiogram will show predominantly systolic cardiac dysfunction (poor contractility and shortening fraction)

Subclinical dog treatment

-ACE inhibitors and/or pimobendan for early stage cardiac dilatation

-arrhythmias: therapy is needed→ ventricular tachycardia (boxers, dobermans): Sotalol, Amiodarone, Mexilitine, low dose Atenolol

Familial arrhythmic cardiomyopathy- second name, trait type, most common breed

ARVC- Arrhythmogenic right ventricular cardiomyopathy

-autosomal dominant trait most common in Boxers

-mild to sever forms

-VPC occurs and can cause sudden cardiac death at a young age if severe enough

ARVC diagnosis

-24 hour Holter monitor to assess severity and response to treatment (VPC are too intermittent and an ECG might over or under estimate frequency)

3 levels of ARVC severity

Asymptomatic VPC

-no strict diagnosis criteria

->100 VPCs per 24 hrs or runs of couplets, triplets, or ventricular tachycardia is consistent with disease and > 1000 VPC per 24 hrs, runs, of ventricular tachycardia, or evidence of R on T warrant treatment

Symptomatic with syncope

-2 options: Sotalol or combo of Mexilitine and Atenolol (if one has poor response, use another)

Systolic dysfunction and heart failure

-treat as dogs with DCM

-supplementation of L-carnitine