Discussion 113 



Lindop : There are two studies going on in this country on athero- 

 sclerosis in poultry (Saxl, H., in press; Hall, D. A., in press). One is 

 done by the Ovaltine workers who are keeping two groups of animals 

 on identical diets, but one group has limited exercise. These groups 

 are being followed for the development of atherosclerosis. The 

 other study, at Leeds, is more on the cytological and the biochemical 

 side. There they have been able to produce atherosclerosis in poultry 

 which have limited exercise, and they have also been able to reverse 

 atherosclerosis in poultry which have been allowed to exercise after 

 they had been inhibited. Atherosclerosis developing in zoo animals 

 might therefore be caused by the comparatively limited exercise 

 they get. 



Scheidegger : The problem really concerns the age of these birds. 

 This old vulture lived in the zoo for about 5Q years. It came as a 

 young bird, at the age of 3 or 4 years, and the food was always the 

 same. In its last year the bird had severe arteriosclerosis. The ages 

 of the other birds are not known, and I cannot tell you what the 

 birds had to eat in captivity. 



Jalavisto : Orma has made observations on cholesterol-fed poultry 

 and it seems that even a little exercise may be enough to retard 

 development of atherosclerosis. He put the food on one side of a 

 fence, and the water on the other side. The poultry drink after they 

 have eaten and therefore have to go over the fence and back again all 

 the time. That could be very easily arranged in a zoo, and it would 

 be one means of checking easily whether it is exercise or something 

 else which is operative in this case. 



Nigrelli: Arteriosclerosis and atherosclerosis can be induced 

 experimentally by dietary methods in poultry, as Dr. Lindop said, 

 and I think there is some relationship with the pantothenic acid in 

 the diet. 



Comfort: The blood pressure of these birds in relation to their con- 

 figuration may have some effect. It is just conceivable that birds of 

 the flamingo type, which have both a long neck and a considerable 

 change of posture between their head-erect and head-down positions, 

 have larger fluctuations in blood pressure than other animals. It is a 

 point which needs investigation. 



The other point is that I am quite sure all zoo birds and animals 

 are better fed, or more consistently fed, than they are in the wild. 

 I rather suspect that, like Dr. Berg's rats, these birds would be less 

 likely to get atherosclerosis if they were only fed intermittently. I 

 suspect that in the wild the vulture does not feed every day, or even 

 every week, unless he is lucky. 



Bourliere: I understand that a study is already under way in 



