Pathologic findings and causes of death in bottlenose dolphins Tursiops truncatus stranded along the Georgia coast, USA (2007-2013).

Between 2007 and 2013, before the 2013 cetacean morbillivirus outbreak, 26 fresh bottlenose dolphin carcasses were necropsied on the coast of Georgia, USA. Here, we present the pathological and microbiological findings associated with their most likely causes of death. The primary cause of death was determined in 25 individuals and included systemic bacterial infection (n = 7), verminous and bacterial bronchopneumonia (n = 5), drowning/entanglement (n = 5), disseminated histoplasmosis (n = 1), intestinal intussusception (n = 1), vegetative endocarditis (n = 1), meningitis (n = 1), necrotizing dermatitis (n = 1), disseminated angiomatosis (n = 1), emaciation (n = 1) and stingray spine trauma (n = 1). Histiocytic and eosinophilic bronchopneumonia associated with Halocerchus sp. infection was observed in 69% of the animals (18/26) and eosinophilic gastritis due to Anisakidae nematodes was found in 36% of the examined stomachs (8/22). Moderate to severe eosinophilic pancreatitis with fibrosis was observed in 4 animals infected with Brachycladiidae trematodes. Proliferative and ulcerative lymphoplasmacytic dermatitis was found in 5 animals and was considered to contribute to deteriorated health status in 2 calves. Pulmonary and lymph node angiomatosis were observed in 15 and 10 animals, respectively. In at least 2 animals, the concentration of polychlorinated biphenyls (PCBs) in the blubber exceeded 1500 µg g-1 of lipid. Bottlenose dolphins stranded on the Georgia coast have a wide range of inflammatory lesions associated with a variety of helminth, bacterial, and fungal pathogens. Some resident animals have also been exposed to high levels of PCB contamination, which could reduce host immunocompetence. Higher exposure to these or other pathogens could result in further decline in the health of resident and migrant dolphin populations in this region.

Ovine footrot: new insights into bacterial colonisation.

Ovine footrot is characterised by interdigital dermatitis (ID) and by the separation of the skin and hoof horn (under-running footrot). Dichelobacter nodosus is the essential pathogen causing footrot; the role of other microorganisms in this disease remains unclear. The aims of this study were (i) to investigate the colonisation of D nodosus, Fusobacterium necrophorum and Treponema species in biopsies from the ovine interdigital skin of healthy, ID and footrot-affected feet and (ii) to characterise the virulence of D nodosus strains in those biopsies. Postslaughter biopsy samples (n=241) were collected and analysed by real-time PCR to determine prevalence and load of the different bacterial species. The highest prevalence and load of D nodosus were found on feet with ID. The vast majority of samples contained virulent D nodosus and some samples contained both virulent and benign D nodosus Notably, the more pathogenic subspecies of F necrophorum was found in samples from UK sheep. Our findings provide further insights into the role bacterial colonisation may play in the early stage of ID and in the progression towards footrot.