Decompression sickness, a condition in whales caused by bubble formation in certain body tissues from dissolved inert gases. It occurs during transition from a high pressure environment to one of lower pressure, resulting in a range of conditions from itching to joint pain, convulsions, and death. A carcass of a stranded Sei Whale, Balaenoptera borealis, found on the shores of southern coast of Peninsular Malaysia was presentedfor postmortem. Investigation results showed that the male Sei Whale, named Si Corner showed pathologic lesions as seen from histology with the formation of fibrosis, emphysema and edema in the lungs and hepatic atrophy which indicated chronic starvation. It believedthat he also suffering from “Barotrauma or decompression sickness” which affected the ear or lungs which lead to unbalanced movement due to changes in air pressure.This may have caused the whale to beach and consequent mortality. The pathologic lesions found give an insight into possible causes of death of beached whales inMalaysia.

A detailed post mortem was carried out on a male Bryde’s whale
Balaenoptera brydei, a cetacean of suborder Mysticetes, with a wide geographical distribution. The stranded whale, weighing approximately 3.5 metric tons was found beached along the Pekan Nenasi River, Pahang in East Coast of Malaysia facing South China Sea. Gross pathology showed severe hemorrhagic gastritis, probably
due to foreign material found compacted in the multichamber stomach, severe congestion in the various vital organs due to toxemia, and severe endoparasite burden in the intestine. Thousands of Digeneans
were found in both the caecum and colon. Morphological identification was carried out on these parasites which were identified as Ogmogaster species. As co parasites, the acathocephalan worms Falsifilicollis species was also detected in the large intestine. Histological examination indicated severe bronchointerstitial embolic pneumonia, chronic interstitial
hemorrhages, intra alveolar septa thickening in lung tissue; chronic hepatic interstitial hemorrhage, hepatocellular and centrilobular degeneration on the liver tissue; renal tubular and glomerular
necrosis in kidney tissue; splenic necrosis and hemorrhages; intestinal mucosal layer necrosis and severe intestinal villi necrosis. The continuing survival of Bryde’s species whale is precarious, because of disregard for appropriate measures for their
conservation and to conduct appropriate study for the cause of death.