PETIGREE MAGAZINE ISSUE 4 - Page 49

P E T S At this speed, if they were running a marathon, Siberian Huskies would cross the finish line in less than an hour and half, at least half an hour faster than the human word record of 2:03’23” set by Wilson Kipsang, Kenyan, in September 29, 2013, at the Berlin Marathon. Champions A list of animals that can outrun a man would not be complete without the camel, the pronghorn and the ostrich. The North American pronghorn has evolved to escape wolf attacks. This explains why it can hold up the speed of 48 km/hour for about an hour. The only bird on the list, the ostrich, has long legs, strengthened by a formidable group of tendons that work storing and releasing elastic energy to produce the best output. An ostrich can run the 42.2 kilometres of a classic marathon in about 45 minutes. The camel, on the other hand, would probably run a marathon in less than 2 hours in special occasions. Ape epic Our closer primate cousins, chimpanzees and bonobos, avoid exercise as scourge. They do not roam around more than 1-3 kilometres a day. Therefore we might expect them to be statistically more prone to heart attacks than humans. Cardiac diseases caused by plaques of fat deposited in the coronary vessels (atherosclerosis) constitute the number one killer of humanity but they are very rare in wild chimpanzees despite their idle lifestyle. Covert Killer Their problems arise from an excessive accumulation of fibrotic tissue within the heart muscle that eventually causes anomalies of the rhythm that leads to death. The phenomenon has also been observed in gorillas and orang- utans, indicating that it probably affected the progenitors of all great apes, including humans. The metabolism of cholesterol differs significantly between human primates, apes and monkeys. Our different susceptibility to occlusive heart disease lies in the biological differences that sprang out occasionally during our common evolution. Then, for yet undisclosed reason we shred off this unfortunate propensity from our hearts. But cardiac diseases associated with fibrous tissues persist within humans. Fibrotic cardiac tissue has caused fatal alteration of the rhythm (arrhythmia) and sudden death in highly trained marathon runners following life-long repetitive bouts of arduous physical activity. Evidently, the deposit of fibrotic tissues that ultimately leads to death can arise either from psychological stress in captive animals or from physical stress in humans, despite enduring strenuous exercise! Nonetheless, heart disease is one of the main causes of death among captive chimpanzees, including individuals kept in zoos and circuses, whose diet and stress levels are similar to those of humans, but with an interesting and fundamental difference. A heart attack happens in humans when a plaque of fat blocks the circulation of blood in a coronary artery, thus preventing the flow of nutrients to reach the internal tissues. Plaques are prevalently constituted by cholesterol. Scientists discovered that captive chimpanzees oft en have high cholesterol levels and rocketing blood pressure that might be considered indicators of high coronary risk if they were humans. However, there is no sign of coronary blockage in chimpanzees succumbing to heart disease. Cholesterol and blood pressure are not the cause of their sudden demise, researchers say. So, what do we have to blame? 49