DISEASE SUMMARY PAGE

Arteriosclerosis in Elephants

Summary Information
Diseases / List of Miscellaneous / Metabolic / Multifactorial Diseases / Disease summary
Alternative Names --
Disease Agents
  • The condition seems to be multifactorial. (J46.147.w1)
    • The diet may play a role in the pathogenesis. (J46.147.w1)
    • Age has been showed to be directly associated with the disease. (J46.147.w1)

Further information on Disease Agents has only been incorporated for agents recorded in species for which a full Wildpro "Health and Management" module has been completed (i.e. for which a comprehensive literature review has been undertaken). Only those agents with further information available are linked below:

Infectious Agent(s) --
Non-infectious Agent(s) --
Physical Agent(s) --
General Description
  • In wild animals, arteriosclerosis lesions occur mainly in the aorta; however in birds the brachiocephalic arteries are commonly involved as well as the aorta. (B35.7.w8)
  • A common type of arteriosclerosis found in wild animals is atherosclerosis, involving changes in the intima (focal accumulation of cholesterol, other lipids, complex carbohydrates, blood, fibrous tissue and deposited calcium; the media may be involved in the lesion breaches the internal elastic lamina. This type of lesion may develop into an atheromatous plaque, on which a thrombus can develop, in some cases occluding the vessel. (B35.7.w8)

In Elephants

  • Note: Simple deposition of lipid in the linings of arteries, particularly "around the musculo-elastic collars, ramps and ridges which reinforce the origins of arterial branches or bifurcations in the aorta or larger arteries" have been found in normal healthy elephants of both sexes and all ages, and particularly in suckling calves and in pregnant and lactating females. This may be considered normal in elephants. (B453.7.w7)
    • These were described as "yellowish-white, slightly raised streaks posterior to the orifices of the branch arteries" of the coronary arteries. (J98.1967ii.w1)
  • Lesions of arteriosclerosis in elephants are more common in the aorta than in the coronary arteries, and are more severe in the abdominal aorta than in the thoracic aorta. (B461.185.w185)
  • In Loxodonta africana - African Elephant, there appears to be no correlation between the severity of lesions and blood levels of cholesterol, phospholipids, triglicerides or free fatty acids. (B461.185.w185, J42.80.w2, J361.16.w1)

Clinical signs:

  • Decreased motility. (B450.14.w14, P5.39.w1)
  • Lethargy. (B450.14.w14, P5.39.w1)
  • Head drooping. (B450.14.w14)
  • Lameness. (J360.9.w1)
  • Stiffness. (J360.9.w1)
  • Emaciation. (B450.14.w14, P5.39.w1)
Gross Pathology:
  • In a study on 415 culled elephants from Murchison Falls National Park, Uganda and Tsavo (East) National Park, Kenya, arteriosclerosis was detected in 72% of aortas and 27% of coronary arteries. Two types of lesions were found. (J98.1967ii.w1)
    • Intimal lesions: spots, streaks or plaques, arising from the intima, 1 - 50 mm in diameter. These were white, raised, glistening and rounded. Predilection sites included the aortic arch and upper thoracic aorta, and the abdominal aorta posterior to the renal arteries.(J98.1967ii.w1)
    • Medial sclerosis: smooth flat, often brittle, plaques, irregular in outline, - 20 mm in diameter, light yellow to brown. Predilection sites for these lesions were the lower thoracic and abdominal portions of the aorta. (J98.1967ii.w1)
    • In severely affected animals, particularly in the aorta, sometimes both types of lesions occurred together. (J98.1967ii.w1)
  • In a study of 207 elephants culled in the Luangwa Valley, Zambia, the earliest lesions, found near the orifices of the branch arteries, were 1 - 6 mm diameter plaques, with calcification evident in incised lesions. Lesions were found mainly between the iliac arteries and a point 4 - 6 cm cranial to the mesenteric arteries. (J42.80.w2)

Histopathology:

  • Atherosclerotic lesions in elephants were found to be more severe in the aortas than in the coronary arteries. (P5.39.w1)
  • The lesions in the abdominal aortas of the elephants studied were more severe than the lesions in the thoracic aortas. (P5.39.w1)
  • Intimal lesions involving hyperplasia, disrupted internal elastic lamella, hyaline degeneration and in advanced lesions, calcification of the intima. (J342.61.w1)
  • Intimal atherosclerosis lesions showed fibrous thickening of the tunica intima with degenerative changes such as necrosis, hyalinisation, softening, lipid deposits, lymphocytic infiltration and calcification. (J361.16.w1)
  • Medial sclerosis lesions showed calcified fibrotic plaques of the inner tunica media, where the medial smooth muscle fibers are atrophied and replaced by fibrotic tissue. (J61.21.w1)
  • In three wild Loxodonta africana - African Elephants from the Kruger National Park: (J62.38.w2)
    • Mineralisation of the tunica media of the thoracic aorta in one animal. (J62.38.w2)
    • In the second elephant the intima and adjacent media of affected areas of aorta were described as very fibrous, few cells were present, the elastica interna was only very mildly eosinophilic and in parts was disintegrating. In the lower aorta, there were mineralised areas of the tunica media. (J62.38.w2)
    • In the third elephant, there was a "myxomatous substance in the intima" causing thickening of parts of the aorta. (J62.38.w2)
  • In a study on 415 culled elephants from Murchison Falls National Park, Uganda and Tsavo (East) National Park, Kenya, arteriosclerosis was detected in 72% of aortas and 27% of coronary arteries. Two types of lesions were found. (J98.1967ii.w1)
    • Intimal lesions: fibrous tissue proliferation, internal elastic lamina disrupted and fragmented, and sometimes degenerative changes in the intima. In older lesions, collagen formation was pronounced and there was a tendency to intimal hyalinisation. In the deeper layers of the intima, there was lymphocyte and plasma cell infiltration and commonly, between collagen fibres, were spindle-shaped spaces, thought to contain collagen. Lipid deposition was noted in deep layers of the intima in some lesions, but wan not a consistent finding. In advanced lesions the fibrotic plaque showed ulceration and calcification. In the media there was muscle fibre atrophy and "fragmentation, loss and reduplication of the elastica". (J98.1967ii.w1)
    • Medial sclerosis: no changes in the intima. In the media, pronounced fibrosis and calcification, with the internal elastic lamina often obliterated. Occasionally the overlying endothelium was lifted off the surface due to the medial calcification, and ulceration occurred. (J98.1967ii.w1)
  • In a study of 207 elephants culled in the Luangwa Valley, Zambia, intimal lesions often were found overlying lesions of the media. (J42.80.w2)
  • Intimal atherosclerosis involved proliferation of fibrous tissue, together with degenerative changes - necrosis, hyelinisation, accumulation of lipid, infiltration of lymphocytes and calcification. (J361.16.w1)
  • Medial sclerosis involved development of calcified fibrotic plaques in the inner tunica media of the vessels, with calcification apparently starting in the internal elastic lamina, and with smooth muscle fibres of the media being replaced by fibrous tissue. (J361.16.w2)
Further Information

Susceptibility:

  • Lesions are found more frequently in older animals. (J42.80.w2, J98.1967ii.w1, J361.16.w1)
    • In a study on 415 culled elephants from Murchison Falls National Park, Uganda and Tsavo (East) National Park, Kenya, elephants did not have grossly visible lesions of arteriosclerosis prior to puberty. Occurrence and severity of lesions increased with age, and medial lesions occurred in advance of intimal lesions. (J98.1967ii.w1)
    • In a study of 207 elephants culled in the Luangwa Valley, Zambia, lesions were never present in elephants under ten years of age. (J42.80.w2)
    • Lesions of intimal atheroscleosis increase with age. (J361.16.w1)
    • Lesions of medial sclerosis increase with age. (J361.16.w2)
  • Initial studies found that females appeared to have a higher incidence of arteriosclerotic lesions; however later it was determined that there were no statistical difference in incidence of either intimal or medial lesions between females and males. (J42.80.w2, J98.1967ii.w1, J361.16.w1, J361.16.w2)
    • In a study on 415 culled elephants from Murchison Falls National Park, Uganda and Tsavo (East) National Park, Kenya, arteriosclerosis was more common in females than in males of the same age. (J98.1967ii.w1)
    • In a study of 207 elephants culled in the Luangwa Valley, Zambia, only 38 males ten years old or older were present in the sample, but it appeared that onset of arteriosclerosis was later than in females, or its incidence was lower. (J42.80.w2)
    • Further studies found there was no significant difference in the severity of either intimal or medial lesions between males and females. (J361.16.w1, J361.16.w2)

Environmental factors:

It has been suggested that arteriosclerosis in wild Loxodonta africana - African Elephants is related to disturbed habitats (J360.9.w1) and that the following environmental factors may influence the development of arteriosclerosis in wild Loxodonta africana - African Elephants:

  • Prolonged exposure to strong sunlight. 
  • Overpopulation/overcrowding. 
  • Restricted diet, due to human population pressures. 
  • Diet high in calcium. Restricted movement, preventing movement to salt licks. 
  • Prevention of migration, with associated breakdown of suitable environmental conditions for young calves, boredom, lack of exercise and overcrowding. 

(J342.61.w1, J360.9.w1, J361.21.w1, J391.32.w1)

Occurrence in Elephants:

Elephas maximus - Asian Elephant:

Loxodonta africana - African Elephant:

  • Arteriosclerotic lesions were reported in the coronary arteries of captive Loxodonta africana - African Elephants. (J46.147.w1)
  • Arteriosclerotic lesions were reported in 36% of 207 aortas examined from Loxodonta africana - African Elephants in Zambia. (J42.80.w2)
  • Arteriosclerosis of the thoracic aorta was found in three wild Loxodonta africana - African Elephants from the Kruger National Park. (J62.38.w2)
  • Arteriosclerotic lesions were reported in free-living Loxodonta africana - African Elephants from two different lowland habitats in East Africa, both considered degraded (in and around Queen Elizabeth National Park and Murchisons Falls National Park, Uganda, and in and around Tsavo National Park, Kenya), but not in elephants from upland montane forests and adjacent alpine moorlands in Kenya and Uganda. (J360.9.w1)
    • Medial sclerosis, characterised by calcium deposition in the muscular layer of the aorta, coronary arteries and main arteries of the neck and limbs. (J360.9.w1)
    • Human atheroma-like lesion, characterised by excessive fatty deposits in the inner layer of arteries. (J360.9.w1)
  • A later study revealed similar arteriosclerosis lesions in free-living Loxodonta africana - African Elephants in East Africa: (J361.16.w1, J61.21.w1)
    • Intimal atherosclerosis of the aorta, brachial, renal and iliac arteries. (J361.16.w1)
    • Medial sclerosis of the aorta, coronary arteries and aortic branch arteries. (J361.21.w1)
  • In a study on 415 culled elephants from Murchison Falls National Park, Uganda and Tsavo (East) National Park, Kenya, arteriosclerosis was found in 298 of 415 aortas (72%) and 29 (27%) coronary arteries. It was more common in females than in males of the same age. Elephants did not have grossly visible lesions prior to puberty. Occurrence and severity of lesions increased with age, and medial lesions occurred in advance of intimal lesions. (J98.1967ii.w1)
  • In a study of 207 elephants culled in the Luangwa Valley, Zambia, lesions were found in less than 40% of elephants. They were never present in elephants under ten years of age. Only 38 males ten years old or older were present in the sample, but it appeared that onset of arteriosclerosis was later than in females, or its incidence was lower. (J42.80.w2)
  • In a study of 463 elephants culled in East Africa (Uganda and Kenya), plaques of intimal atherosclerosis were detected in the aorta, coronary arteries, renal arteries and iliac arteries. (J361.16.w1)
  • In a study of 463 elephants culled in East Africa (Uganda and Kenya), medial sclerosis was detected in the aorta, the coronary arteries and the aortic branch arteries. (J361.16.w2)
Associated Techniques
Host taxa groups /species Further information on Host species has only been incorporated for species groups for which a full Wildpro "Health and Management" module has been completed (i.e. for which a comprehensive literature review has been undertaken).

(List does not contain all other species groups affected by this disease)

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