HEART DISEASE

©The DCM - Dil. Cardiomyopathy - by D. Caroline Coile, PH.D.,
published in DOGWorld, Dec. 1999, submitted by Nancy Abel - USA
-summary of article by E. Steffen -

Summary:

DCM is a progressive disease, the muscles of the heart lose their contractility. In many cases dogs don't display symptoms until the condition has advanced significanly. DCM is one of the mos common serious cardiac diseases in dogs.

Symptoms often appear to develop quite suddenly; this is exp. true in dogs that normally are not very active. The condition for DCM is developing slowly (probably 6 mths. to 18 mths.). In active and working dogs it's noticed earlier as the dog loses it's ability to excerise.

DCM mostly is a disease of large and giant breeds 
(but can also strike other breeds).

Scottish Deerhound - Doberman Pinscher - Irish Wolfhound -  Great Dane - Boxer - St. Bernard - Afghan Hounmd, Newfoundland - Old English Sheepdog - English Cocker Spaniel - English Springer Spaniel - American Cocker Spaniel - Labrador Retriever and Golden Retriever - are the most affected breeds.
DCM is seen roughly twice as often in males than females (own remark: hormonal influence ??).

Most dogs presented with symptoms are between 4 & 10 yrs. old; the incidence incr. with age.
A few dogs are diagnosed with DCM before reaching 1 yr. of age.

Diagnostic Procedure

Preliminary tests can be done by a general vet. Blood- & urine tests may reflect effects of low cardiac output.

X-ray of the heart
will show some degree of cardiac enlargement (cardiomegaly).
About half of the dogs in auscultation moderate heart murmurs are found. Heart rate is usually rapid (more than 200 beats p.m.)
Most dogs with DCM have some abnormalities shown in EKG.

Ultrasound:
the sound waves show int. structures of the heart, the heart valves, size of heart chambers, thickness of heart muscle and how well the heart is contraction.

Etiologies

In most cases the cause of the condition is unknown (idiopathic).
Might be influenced by nutritional deficiencies, metabolic disorders, cardiac toxins, inflammations, trauma, tumors, infections.

L-Carnitine (found in red meat) is essential for the mitochondrial transport of fatty acids, helps rid the mitochondria of some pot. toxic metabolities.
Toxine (in drugs and / or plants), viruses (parvovirus, distemper,other viruses), parasites (worms) - can have an influence on developing DCM.
Heredity: some preliminary evidence (autosomal dominant mode of inheritance( has been reported in a family of Boxers. DCM in dogs could reflect different genetic etiologies among breedsand perhaps even within single breeds.

Treatment - Therapies

Unfortunately, DCM cannot be prevented or cured. 
Most dogs live only 6 - 12 mths. after the onset of symptoms, some live serveral years, some others only a few weeks after diagnosis.

Current therapies can improve and prolong a dog's quality of life 
- but they have their limits.


Low-sodium-diet, replacing substances such as L-carnitine or taurine.

Diuretics (to avoid excessive fluid in lungs)
Digitalis glycosides - help the heart to contract better
ACE-inhitibors increase the vasodilation - may help to prolong life.

Supplements - L-carnitine - Taurine - Co-enzyme Q10-supplementation - Fish oil

Lifestyle

Owners of dogs suffering from DCM should observe certain precautions.
No exercises - low-sodium-diet (commercial or home-made) - no anesthesia if not absolutely necessary/extensive precautions.

research on DCM is continued.