PATHOLOGY OF CARDIAC ATRIAL ANEURYSMS IN CATTLE

In our study we examined for the presence of atrial aneurysms 6348 cat tle. 2493 calves (75 % males) of French (80 % Garonnaise, Charolaise a nd Limousine) arid Piemont (20 %) breeds were between 6 and 7 months W hereas 3855 heads of beef cattle (90 % males), mainly imported form Ea st Europe and France, were between 18 and 20 months of age. Atrial ane urysms were divided in muscular and fibrotic. Fibrotic aneurysms have been detected in 2.8 % in calves and in 7.37 % in cattle, mainly in th e right atrium. Fibrotic aneurysms have been thought to be defects of the wall of the right atrium and, therefore the result of a developmen tal disorder. In analogy with the cirsoid aneurysms, the ansurysms pre sent under the epicardium or in the adipose tissue can be interpreted as a developmental detect of coronary arteries. Atrial muscular aneury sms have been detected only in calves and were located in both right ( 7) and left (8) atria. It is possible that one of the factors involved in the development of these lesions is a dietary deficiency due to an inappropriate diet.