Abstract
This thesis describes the nature, frequency and severity of some spontaneous cardiovascular diseases in a series of 200 unseleeted doge. This
study concentrated on two conditions, chronic valvular disease and
arteriosclerosis.
It was established that chronic valvular disease was a mucoid degeneration of the spongiosis and fibrosa of the valves. These lesions occurred
with the greatest frequency and severity in the left atrioventricular valve
where thoy g&vo rise to valvular insufficiency and congootivo heart failure
in 6.C1' of cases. Similar lesions occurred in the other heart valves but
they were rarely associated with clinical disease. It was shown that chronic
valvular disease increases in frequency and severity with advancing age,
particularly in the left atrioventricular valve. These lesions tended to
develop more rapidly in the male than in the female and did not appear to
have any breed predisposition, nor were they associated with diseases in
any particular body system. Age emerged as the most important single aetiological factor.
Two different changes were seen in the posterior aorta and coronary
circulation. One, a fibrous intimal plaque of no clinical significance
and tho other an amyloid degeneration of the intramural coronary vessels
of the left ventricle. This lesion may have some clinical significance
when associated with chronic valvular disease.
Other cardiovascular diseases were observed and recorded.
