Dwarfing of swine maintained in large groups with relatively little space per animal may be attributed to psychosocial factors. Intramural coronary arteriosclerosis developed at approximately the same rate in dwarfed and normally developing animals. Lesions in arteries of the left posterior papillary muscle were more advanced than in the left anterior papillary muscle of the same animal, irrespective of its growth rate, and often were more advanced than in swine twice as old.
References
1.
RatcliffeH. L.:
Age and environment as factors in the nature and frequency of cardiovascular lesions in mammals and birds in the Philadelphia Zoological Garden.Ann. N. Y. Acad. Sci.127:
715–735(1965)
2.
RatcliffeH. L.:
Environment, behavior and disease. Observations and experiments at the Philadelphia Zoological Garden.
Trans. Studies Coll. Physicians, Philadelphia 1968,
pp. 7–21
(Waverly Press,
Baltimore1969)
3.
RatcliffeH. L.:
Contribution of a zoo to ecology of disease.
Proc. Am. Philosoph. Soc., Philadelphia 1968,
pp. 235–244
(American Philosophical Society, Philadelphia
1969)
4.
RatcliffeH. L.SnyderR. L.:
Myocardial infarction. A response to social interaction among chickens.Science, N. Y.144:
425–426(1964)
5.
RatcliffeH. L.SnyderR. L.:
Arteriosclerotic stenosis of the intramural coronary arteries of chickens. Further evidence of a relation to social factors.Br. J. exp. Path.48:
357–365(1967)
6.
RatcliffeH. L.LuginbühlH.SchnarrW. R.ChackoS.:
Coronary arteriosclerosis in swine: evidence of a relation to behavior.J. comp. physiol. Psychol.68:
385–392(1969)
7.
PowellG. F.BrazelJ. A.BlizzardR. M.:
Emotional deprivation and growth retardation simulating idiopathic hypopituitarism. I. Clinical evaluation of the syndrome.New Engl. J. Med.276:
271–278(1967)
8.
PowellG. F.BrazelJ. A.RaitiS.BlizzardR. M.:
Emotional deprivation and growth retardation simulating idiopathic hypopituitarism. II. Endocrinologic evaluation of the syndrome.New Engl. J. Med.276:
1279–1283(1967)
9.
HafezE. S. E.SumptionL. J.JakwayJ. S.:
The behavior of swine; in
Hafez The behavior of domestic animals
(Williams & Wilkins,
Baltimore1962)
10.
SnedecorG. W.CochranW. G.:
Statistical methods;
6th ed.
(Iowa State University Press,
Ames1967)
11.
RatcliffeH. L.LuginbühlH.PivnikL.:
Coronary, aortic and cerebral atherosclerosis in swine of three age groups.Implications. Bull. Wld Hlth Org.42:
225–234(1970)
