C. STOUT AND F. BOHORQUEZ 843 
Table III. — Taxonomic Classification and Prevalence of Arterial Lesions in Hoofed Mammals 
Number of Animals % of Aorta Containing Lesions 
With 
With Fatty 
Fibrous 
Other 
Order 
Common Name 
Scientific Name 
Total 
Lesions 
Atheroma Steaks 
Plaques 
Perissodactyla 
Donkey 
Equus asinus 
5 
1 
1 
tr 
Zebra 
Equus burchelli 
2 
1 
tr 
ir 
Tapir 
Tapirus sp 
1 
1 
tr 
Artiodactyla 
Alpaca 
Lama pacos 
1 
1 
tr 
Arabian camel 
Camelus dromedarius 
2 
2 
2 
1 
Giraffe 
Giraffa camelopardalis 
1 
1 
1 
tr 
Pronghorn 
Antiloeapra americana 
5 
2 
tr 
tr 
Axis deer 
Axis axis 
1 
1 
1 
Barasingha 
Cervus duvauceli 
2 
Wapiti 
Cervus canadensis 
7 
5 
tr, tr, 2, 2, 5 
tr, 1, 2, 5 
+ , +. +. + 
Reindeer 
Rangifer tarandus 
2 
1 
tr 
+ 
Mule deer 
Odocoileus hemionus 
9 
7 
tr, tr, tr, 1, 1, 1 
1, 1, 2, 2 
+, +, + 
White-tail deer 
Odocoileus virginianus 
7 
6 
1, 1, 1, 4, 10 
1, 2, 5 
+■ + 
Muntjac 
Muntiacus muntjak 
1 
1 
1 
5 
Zebu 
Bos indicus 
4 
2 
1 10 
tr, 3 
American bison 
Bison bison 
1 
1 
tr 
tr 
Sitatunga 
Tragelaphus spekei 
7 
4 
tr, 1 
tr, tr, 5, 10 
Greater kudu 
Tragelaphus strepsiceros 
6 
6 
tr, tr, tr, tr, 1 
tr, tr, tr, 1, 3 
Nyala 
Tragelaphus angasi 
2 
2 
tr 
tr 
Nubian ibex 
Capra ibex 
3 
2 
tr, 2 
tr, 1 
Markhor goat 
Capra falconeri 
4 
2 
tr, 2 
2 
Angora goat 
Capra hircus 
5 
4 
tr, tr, 1, 2 
tr, 1, 2 
Argali 
Ovis ammon 
1 
1 
tr 
10 
Cape hartebeest 
Alcelaphus buselaphus 
1 
1 
1 
Sable antelope 
Hippotragus niger 
2 
1 
1 
+ 
Kob 
Kobus Kob 
5 
3 
1. 2 
tr, tr 
+ 
Defassa waterbuck 
Kobus defassa 
2 
2 
1, 15 
Addax 
Addax nasomaculatus 
3 
2 
tr, tr 
Topi 
Damaliscus korrigum 
2 
2 
tr, tr 
tr 
Grant's gazelle 
Gazella granti 
11 
10 
tr, tr, tr, tr, 1 
tr,tr,tr,tr,tr,tr,tr 
+ . + ,+,+. + .+.+ 
Blackbuck 
Antilope cervicapra 
10 
3 
tr 
tr. tr, 3 
+ 
Gemsbok 
Oryx gazella 
2 
1 
tr 
tr 
Persian gazelle 
Gazella subgutturosa 
2 
1 
tr 
tr 
African guinea hog 
Potamochoerus porcus 
2 
2 
tr. tr 
tr 
TOTALS 
121 
82 
1 61 
57 
20 
% 
68% 
1% 50% 
47% 
16% 
4- = Medial degeneration and/or calcification 
tr = Trace 
Fibrous (Myoelastie) Plaques. Fibrous 
plaques were found in 57 (47%) of 121 hoofed 
mammals, 19 (18%) of 104 non-human pri- 
mates, 19 (35%) of 54 carvivores, 11 (92%) of 
12 pinnipeds, 42 (58%) of 72 birds, and 8 
(19%) of 42 exotic mammals. (Table I) Fi- 
brous plaques were located primarily in the ab- 
dominal segments of the aortas, frequently at 
the iliac bifurcation or trifurcation. From 
traces to 3% of the intimal surface of the aor- 
tas contained fibrous plaques in most of the 
individuals. Exceptions were an elderly male rhe- 
sus monkey (Macaca mulatta) with 15%, S pea- 
cocks (Pavo cristatus) with 10%, 12%, and 
15%, respectively, a domestic turkey with 10%, 
a Goliath heron (Ardea goliath) with 15%, an 
argali (Ovis ammon) with 10%, and 3 Califor- 
nia sea lions (Zalophus calif ornianus) with 
10%, 10%, and 11% respectively (Tables III- 
VII). Microscopically, the lesions were com- 
posed of smooth muscle and elastic tissue ele- 
ments. In larger plaques, the smooth muscle 
cells of the lesions were sometimes oriented in 
different planes. Most commonly, the cells near- 
est the media were oriented longitudinally or 
obliquely, while those adjacent to the lumen 
were oriented circumferentially. The internal 
elastic lamella was usually intact beneath small 
lesions and fragmented or absent beneath 
larger ones. Many fibrous plaques contained 
lipid droplets, which were usually distributed 
throughout the thickness of the lesions, but 
were most dense at the outer edges. Foam cells 
and central accumulations of lipid were seen 
primarily in the birds and non-human primates 
(Figures 3 and 4). 
Atherosclerotic Plaques: Atherosclerotic 
plaques were found in 1 (1%) of 121 hoofed 
