| Popis: |
Neoplastic disease, in past years, has been considered an uncommon or rare event in marine mammals. However, in more recent years, with more careful observation of large numbers of stranded and beached animals, the cumulative number of observed neoplasms in these marine animals is constantly growing. Many of the earlier case reports on marine mammal neoplasms were derived from studies of captive zoo animals. Ridgway compiled a tabulation of marine mammal diseases which included 12 reports of neoplasms in cetacea and seven reports of tumors in pinnipeds. Landy presented a literature review of tumors in marine mammals up to 1978, wherein he described 31 tumor reports in cetacea and 40 reports of tumors in pinnipeds. Based on this summary review of marine mammal neoplasms, it would appear that neoplasms are somewhat more common in pinnipeds than in cetaceans, but this may be biased because of a greater sampling of pinnipeds. |
