Dental and Temporomandibular Joint Pathology of the Eastern Pacific Harbour Seal (Phoca vitulina richardii)

Dental and Temporomandibular Joint Pathology of the Northern Fur Seal (Callorhinus ursinus)

“…Congenitally missing teeth were uncommon (0.6% of teeth); this finding is consistent with previous studies of dental pathology in the Californian sea lion (Z. californianus) and the Eastern Pacific harbour seal (Phoca vitulina richardii), in which the prevalence of congenitally absent teeth was 0.1% (Sinai et al, 2014) and 0.2% (Aalderink et al, 2015), respectively. Prevalence of malformations is slightly higher in the northern fur seal (0.2% of teeth), compared with the California sea lion and the harbour seal, with 0.03% (Sinai et al, 2014) and 0.07% (Aalderink et al, 2015) of teeth malformed, respectively. A double root was found on 14 teeth (0.3%) and all other teeth that were available for examination had a single root.…”

“…Pathological conditions are likely overrepresented in stranded animals compared with the general population (Cowan, 2002), and high numbers of stranded animals may be considered sentinels of emerging diseases (Gulland, 1999). Previous studies on southern sea otters (Enhydra lutris nereis) (Winer et al, 2013), California sea lions (Zalophus californianus) (Arzi et al, 2015b) and Eastern Pacific harbour seals (Phoca vitulina richardii) (Aalderink et al, 2015) have revealed numerous dental lesions and a surprisingly high incidence of temporomandibular joint (TMJ) pathology of unknown aetiology. This study aims to determine the nature and prevalence of dental pathology and TMJ pathology in northern fur seals by examining museum specimen skulls.…”

Dental and Temporomandibular Joint Pathology of the Walrus ( Odobenus rosmarus )

“…While acquired tooth loss Dental Pathology of the Walrus was relatively infrequent, affecting only 3.3% of teeth, it was more prevalent than is documented in other marine mammal species: 0.7% of teeth in the northern elephant seal (Abbott and Verstraete, 2005), 0.6% of teeth in the southern sea otter (Winer et al, 2013), 0.4% of teeth in the California sea lion (Sinai et al, 2014), 0.8% of teeth in the northern fur seal (Aalderink et al, 2015a) and 2.3% of teeth in the eastern Pacific harbour seal (Aalderink et al, 2015b). Dental fractures were also relatively rare (1.3%), about as common as in the northern elephant seal (1.2%) (Abbott and Verstraete, 2005) and northern fur seal (1.1%) (Aalderink et al, 2015a). Nearly three-quarters of all fractures affected the maxillary canine teeth, which could potentially have devastating consequences, as the tusks are utilized for myriad functions: for breaking through ice and mounting ice floes, for defence against predators, for threat displays and intraspecific aggression, for communicating and for social displays (Miller, 1975;Fay, 1982;MacCracken and Benter, 2015).…”

“…A series of papers has been published on dental and TMJ pathology of marine mammal species: the northern elephant seal (M. angustirostris) (Abbott and Verstraete, 2005), the southern sea otter (Enhydra lutris nereis) (Arzi et al, 2013a;Winer et al, 2013), the California sea lion (Zalophus californianus) (Sinai et al, 2014;Arzi et al, 2015), the northern fur seal (Callorhinus ursinus) (Aalderink et al, 2015a) and the eastern Pacific harbour seal (Phoca vitulina richardii) (Aalderink et al, 2015b). In general, museum collections of skulls, such as those making up the aforementioned studies and this study, are obtained from strandings, carcass recovery and donations by rehabilitation centres.…”

Dental Pathology of the Hoary Marmot (Marmota caligata), Groundhog (Marmota monax) and Alaska Marmot (Marmota broweri)

“…A series of papers has been published on dental pathology of mammalian species: the northern elephant seal (Mirounga angustirostris) (Abbott and Verstraete, 2005), the southern sea otter (Enhydra lutris nereis) Winer et al, 2013), the California sea lion (Zalophus californianus) (Sinai et al, 2014;Arzi et al, 2015), the northern fur seal (Callorhinus ursinus) (Aalderink et al, 2015a), the Eastern Pacific harbour seal (Phoca vitulina richardii) (Aalderink et al, 2015b), the bobcat (Lynx rufus californicus) (Aghashani et al, 2016), the polar bear (Ursus maritimus) (Winer et al, 2016a) and the walrus (Odobenus rosmarus) (Winer et al, 2016b). In general, museum collections of skulls, such as those making up the aforementioned studies, are obtained from strandings and carcass recovery.…”