Figure 8. — (Z 178) Black bear (Ursus americanus). 
Elderly adult female. Thoracic aorta showing multi- 
ple saccular aneurysms. (Reproduced with permission 
from Amer. J. Path., Harper and Row, Hagerstown, 
Maryland). 
found dead unexpectedly one morning. She had 
been in captivity for the last 14 years of her 
life, and had enjoyed apparent good health. 
Death was due to acute pulmonary edema, and 
the presence of hemosiderin laden macrophages 
in the alveolar spaces suggested chronic left 
ventricular failure. The left ventricle of the 
heart was tremendously hypertrophied, averag- 
ing 2.0 to 2.5 cm. in thickness. The right ventri- 
cle showed mild hypertrophy, measuring 0.3 to 
0.4 cm. in thickness (Figure 17). There was no 
valvular abnormality or other obvious cause for 
the hypertrophy. The main, interlobar and ar- 
cuate renal arteries were normal. However, the 
interlobular renal arteries showed classical 
pseudoelastic hyperplastic sclerosis, and there 
. BOHORQUEZ 853 
Figure 9. — (Z 141) Black bear (Ursus americanus). 
Elderly adult male. Section through the rim of small 
aneurysm showing loss of medial smooth muscle and 
elastic tissue. The overlying intima is thickened by 
hyaline-like tissue. Weigert's elastic stain x 25. (Re- 
produced with permission from Amer. J. Path., 
Harper and Row, Hagerstown, Maryland). 
was focal, pronounced medial and intimal hy- 
pertrophy and hyperplasia in the preglomerular 
and slightly larger arterioles. Focal hyaliniza- 
tion of the afferent arterioles was alpo seen 
(Figure 18), These changes were exactly simi- 
FiGURE 10. — (Z 485) Tamandua (Tamandua tetradac- 
tyla). Adult male. Section through a small aneurysm 
showing degeneration with expansion of smooth mus- 
cle cells with preservation of elastic fibers. Centrally, 
the entire inner media is replaced by granulation-like 
tissue. The overlying intima is thickened by hyaline- 
like tissue. Weigert's elastic stain x 25. (Reproduced 
with permission from Atherosclerosis, Elsevier, Am- 
sterdam) . 
