THE HEART OF THE MATTER

Avi Avner,BSc BVSc CVR MRCVS DVDI

 

Heart testing is used to guide breeders about prevalence of a particular condition in their line and to identify disease in a potential breeding animal so that breeding from that animal is avoided. Furthermore, it is used for the early detection and management of supposedly significant heart conditions. This is only justified if the condition being tested for is inherited. There is an increasing body of evidence that both congenital and acquired cardiac disease has a genetic basis in dogs and some breeds of cats.

Congenital heart diseases in which heart testing is recommended:

-          Boxer: Aortic Stenosis (AS) (Pic. 1, 2)

-          Newfoundland: Dilated Cardiomyopathy (DCM) and AS

-          Irish Wolfhound: DCM

-          Great Dane: DCM

-          Dobermans: DCM

-          Bull Terrier/ Miniature Bull Terrier: Mitral dysplasia  (Pic. 3, 4) and AS

-          Cavalier King Charles Spaniel: Mixomatous Degenerative Valvular Disease (Endocardiosis)

-          Main Coon cats: Hypertrophic cardiomyopathy

 

aortic stenosis1
aortic stenosis

 





 



 

 

 

 

 

 

 

 

 

 

 

 

 



















Picture 1, 2: Aortic Stenosis


Disease predispositions of cardiorespiratory disease: 

Dilated cardiomyopathy

Aortic stenosis

Pulmonic stenosis

Ventricular septal defect

Patent ductus arteriosus

AV valve dysplasia

Mitral valve disease

Boxer                   

Cocker Spaniel

Dobermann

GSD

Golden Retriv

Gordon Setter

Great Dane

Irish Setter

Irish Wolfhound

Labrador

Newfoundland

Old Eng Sh D

St Bernard

Springer Span

 

Boxer

Eng Bull T

GSD

Gold Ret

Newfoundlan

Rottweiller

Samoyed

 

Beagle

Cav King C

Chihuahua

Chow Chow

Cock Span

Eng Bulldog

Fox Terrier

Labrador

Mastiff

Min Schnau

Samoyed

Schnauzer

Shih Tzu

York Terrier

Border Collie

Boston Terr

Eng Bulldog

Spring Span

Keeshond

Westie

 

 

Bord Collie

Cav King Ch

Cocker Span

GSD

Irish Setter

Poodle Miniat

Pomeranian

Shetland Shee

 

Eng Bull T

GSD

Dog De Bor

Great Dane

Labrador

Old Eng Sh

Cav King C

Chihuahua

Cock Span

Fox Terrier

Gordon Sett

Irish Sett

Poodle Min

Schnauzer

Pekinese

Yorkshire T

 

Auscultation

For most congenital heart diseases- especially aortic stenosis (AS) - and for significant mitral valve diseases (MVD), a heart murmur is present; initial testing is by auscultation. In Boxers with AS, heart murmurs are extremely prevalent and grading the murmur (out of 6) is important.

 

 

mitral dis
mitral dis1




 





































Picture 3, 4: Mitarl Dysplasia


Echocardiography

Echocardiography is used to identify the anomaly and assess its severity. Boxers with a grade 2-3/6 murmur may or may not be candidates for breeding. The decision could be made echocardiographically by assessing the aortic outflow velocity.

Echocardiography is also advocated in screening for dilated cardiomyopathy (DCM) {Irish Wolfhounds, Newfoundlands, Dobermanns and Great Danes...}. Many dogs have no abnormalities on auscultation or physical examination with early, pre-symptomatic disease.

 

When to test?

Most congenital heart diseases can be detected by presence of an associated heart murmur at primary health check. However aortic stenosis (AS) can progress and become proportionately worse as the dog grows, so official heart testing should be carried out once the dog is adult (at least 12 months old and, ideally, over 18 months old in giant breeds). For acquired heart diseases, serial examinations are required (e.g. annually).

 

Who can test?

Recognized specialists in Cardiology and or Veterinary Diagnostic Imaging.