Cetacea

Histopathological Differential Diagnosis of Meningoencephalitis in Cetaceans: Morbillivirus, Herpesvirus, Toxoplasma gondii, Brucella sp., and Nasitrema sp.

“…In our study, CeMV-and HV-associated brain lesions were in concordance with previous descriptions (20,32). Comparing these results to those for lesions caused by other aetiological agents under study, we observed that mild malacia was more frequently detected in HV-positive animals, while it was mainly minimal in animals infected by T. gondii, Brucella sp., and CeMV.…”

“…CeMVs are RNA viruses responsible for massive dieoffs worldwide and include three well-characterized strains (porpoise morbillivirus, DMV, and PWMV) and three less wellcharacterized strains detected in Hawaii and in the southern hemisphere (32). CeMV is a well-recognized neurotropic pathogen and localized brain lesions have been described in cetaceans that have cleared systemic CeMV infection, resembling subacute sclerosing panencephalitis (SSPE) and old dog encephalitis (ODE) (20,32,65). IHC labeling has been successfully used to diagnose CeMV preferentially in earlier stages of the disease.…”

“…Brucella spp. infection associated with meningitis, meningoencephalitis or meningoencephalomyelitis has been often reported in striped dolphins (Stenella coeruleoalba) (5)(6)(7)(8)(9)(10)(11)(12)(13), while only a few cases have been reported in the following cetacean species: Atlantic white-sided dolphin (Lagenorhynchus acutus) (14), short-beaked common dolphin (Delphinus delphis) (15), harbor porpoise (Phocoena phocoena) (16), long-finned pilot whale (Globicephala melas) (17), sperm whale (Physeter macrocephalus) (18), and common bottlenose dolphin (Tursiops truncatus) (19)(20)(21). Other bacterial pathogens have been more rarely reported in association with brain or meningeal abscess in stranded cetaceans: Staphylococcus aureus was isolated from a common bottlenose dolphin with acute pyogenic encephalitis and leptomeningitis (22); Listeria monocytogenes was identified, along with Toxoplasma gondii and Brucella spp., in a striped dolphin with severe meningoencephalitis (13); and Vibrio parahaemolyticus and V. alginolyticus were associated with meningoencephalitis in a bottlenose dolphin (23).…”

Diseases and parasites

“…A discrete thyroid gland adenoma was observed on histopathology in a bowhead whale (NSB-DWM 2014B7; Stimmelmayr, 2015 ). Thyroid adenomas (adenomatous hyperplasia) have been previously reported in aged toothed whales ( Newman and Smith, 2006 , St. Leger et al, 2018 ) but not baleen whales.…”

“…The benign tumor presented as multiple (100) discrete sessile burgundy red round masses ranging in size from 0.5 to 1 cm arising from the mesovarium. Uterine leiomyoma, but not angioleiomyoma are among the most commonly reported benign tumors of the female genital tract in cetaceans ( Newman and Smith, 2006 , St. Leger et al, 2018 ). A single stalked and pedunculated cystic white vaginal fibroma (4×2.5 cm 2 ) was observed in a mature female bowhead whale (NSB-DWM 2004B11).…”