Document Type

Article

Publication Date

4-2019

Keywords

Killer whale, Offshore ecotype, Orcinus orca, Periodontal disease

Abstract

A mature, adult female, offshore killer whale (Orcinus orca) was stranded deceased in Portage Bay, Alaska, in October 2015. Full necropsy examination with histopathology was performed. Consistent with previous studies of offshore killer whales, and thought to be a result of their unique elasmobranch diet, all the teeth were significantly abraded and almost flush with the gingival margin. Age was estimated at 30–35 years based on annuli and growth arrest lines in a remaining tooth. The dentate portion of the mandibles were excised en bloc and frozen until imaging could be completed. Radiography and computed tomography revealed lesions consistent with severe abrasion, pulp exposure and evidence of endodontic and/or periodontal disease in nine of the 15 mandibular teeth present (60.0%). Only five (33.3%) teeth were suspected to have been vital at the time of death based on imaging. Lesions were more severe rostrally, with the caudal teeth less affected. Autolysis precluded gingival histopathology and no teeth were analyzed histologically. Necropsy examination revealed a likely multifactorial cause of death, with most significant lesions including the severe chronic periodontal/endodontic disease with abrasion, inanition and emaciation with possible cardiovascular disease. This case highlights the importance of imaging in evaluating periodontal and endodontic status, especially post mortem when other tissues are no longer available, and demonstrates that periodontal and endodontic disease occur naturally in this species and can be a significant cause of morbidity in mature free-ranging killer whales of the offshore ecotype.

Publication Title

Journal of Comparative Pathology

Volume

168

First Page

35

Last Page

40

DOI

10.1016/j.jcpa.2019.03.001

Required Publisher's Statement

Published Open Access.

Link to publisher version: https://www.sciencedirect.com/science/article/pii/S0021997518304845?via%3Dihub#!

Subjects - Topical (LCSH)

Killer whale--Stranding--Alaska--Portage Bay (Kodiak Island); Killer whale--Mortality--Alaska--Portage Bay (Kodiak Island); Killer whale--Diseases--Alaska--Portage Bay (Kodiak Island); Periodontal disease--Alaska--Portage Bay (Kodiak Island)

Geographic Coverage

Portage Bay (Kodiak Island, Alaska)

Genre/Form

articles

Type

Text

Rights

Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.

Language

English

Format

application/pdf

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