Abstract
Cardiomyopathy (CMP) and myocardial degeneration (MCD) are disorders that are believed to be responsible for single strandings of pygmy (Kogia breviceps) and dwarf (Kogia sima) sperm whales from the Atlantic and Pacific oceans. Findings to date suggest that these disorders represent different stages of severity of a chronic progressive disease, with CMP representing the end stage of the continuum. Lesions have been identified primarily in adult males. Histological lesions characteristic of both disorders included anisokaryosis with karyomegaly and nuclear rowing of cardiomyocytes. Kogia spp. are the second most commonly stranded cetaceans in the Southeastern United States, and there is a need to establish the etiopathogenesis of these disorders.
In 2005, we initiated a study to further characterize CMP (n = 19) and MCD (n = 11) in Kogia spp., based on standardized diagnostic criteria established in previous research.1 We expanded our study to include a comparison group without cardiac lesions (n = 10), and included analyses for additional parameters that have been useful for characterizing CMP in terrestrial mammals. Parameters examined included histopathology, demography, hematology and serum chemistry analytes, catecholamines (epinephrine, norepinephrine), dopamine, amino acids (L- carnitine, taurine) and vitamins (selenium and thiamine). Serum and cardiac tissue samples were provided by members of the Southeast United States Marine Mammal Stranding Network. Preliminary results from these analyses provide important insights into the potential cause(s) of CMP in Kogia spp., and serve to enhance our understanding of the relationship between CMP and stranding events.
Acknowledgements
This research was funded by the John H. Prescott Marine Mammal Rescue Assistance Grant Program and the State of Florida Protect Florida Whales specialty license plate program.
Reference
1. Bossart,G D, HensleyG, GoldsteinJ D, KroellK, Manire C A, Defran R H, Reif JS. Cardiomyopathy in stranded pygmy (Kogia breviceps) and dwarf (Kogia sima) sperm whales. Aquat Mamm. 2007;33(2):214–222.