Malignant catarrhal fever in a Vietnamese pot-bellied pig. A potential threat to pigs in mixed-species exhibits?

Malignant catarrhal fever (MCF) represents a sporadic and often fatal disease in various ungulate species including rarely swine. A close contact between susceptible and reservoir species of ovine herpesvirus-2 (OvHV-2) is a requirement for virus transmission. As in ruminants, a rapid course of disease with lymphohistiocytic meningoencephalitis and necrotizing vasculitis in multiple organs is frequently seen in porcine MCF. This report describes a case of MCF in a Vietnamese pot-bellied pig, which was kept in a zoological exhibit with direct contact to various ruminants. It represents the first description of porcine MCF with proven natural OvHV-2 infection in Germany. OvHV-2 should be considered as cause of fatalities among swine especially in mixed-species exhibits as present in many zoological gardens. Also farm pigs kept in free ranging husbandry systems with potential contact to sheep and other ruminant species may be at risk.

Jejunal pseudodiverticulosis in a swamp wallaby (Wallabia bicolor).

Necropsy examination of an 8-year-old female swamp wallaby (Wallabia bicolor) from a zoological garden revealed four intestinal diverticular outpouchings at the mesenteric border of the jejunum, which were partly ruptured causing a fatal peritonitis. Microscopically, affected small intestinal segments were characterized by an abrupt gap in the muscular layer with subsequent herniation of respective mucosal and submucosal layers, interpreted as acquired pseudodiverticula. Multifocal perforations of these diverticula were associated with prominent fibrinosuppurative serositis with leakage of ingesta. In addition, there was intestinal nematodal endoparasitism with accompanying neutrophilic to eosinophilic enteritis. Small intestinal pseudodiverticula resembling human colonic diverticulosis are rare in animals and can lead to fatal peritonitis by faecal impaction, subsequent transmural inflammation and eventual perforation.

Impact of Theiler's virus infection on hippocampal neuronal progenitor cells: differential effects in two mouse strains.

AIMS: Disease-associated alterations in hippocampal neurogenesis are discussed as an important factor contributing to long-term consequences of central nervous system diseases. Therefore, the study aimed to determine the impact of Theiler's murine encephalomyelitis virus infection on hippocampal cell proliferation, neuronal progenitor cells and neurogenesis as well as the influence of microglia on respective disease-associated alterations. METHODS: The impact of the infection was evaluated in two mouse strains which differ in the disease course, with an acute polioencephalitis followed by virus elimination in C57BL/6 mice and a chronic demyelinating disease in SJL/J mice. RESULTS: Infection with the low neurovirulent BeAn strain did not exert significant acute effects regardless of the mouse strain. In the chronic phase, the number of neuronal progenitor cells and early postmitotic neurones was significantly reduced in infected SJL/J mice, whereas no long-term alterations were observed in C57BL/6 mice. A contrasting course of microglia activation was observed in the two mouse strains, with an early increase in the number of activated microglia cells in SJL/J mice and a delayed increase in C57BL/6 mice. Quantitative analysis did not confirm a correlation between the number of activated microglia and the number of neuronal progenitor cells and early postmitotic neurones. However, flow cytometric analyses revealed alterations in the functional state of microglial cells which might have affected the generation of neuronal progenitor cells. CONCLUSIONS: Theiler's murine encephalomyelitis virus infection can exert delayed effects on the hippocampal neuronal progenitor population with long-term alterations evident 3 months following infection. These alterations proved to depend on strain susceptibility and might contribute to detrimental consequences of virus encephalitis such as cognitive impairment.

Systemic Candida albicans infection in two alpacas (Lama pacos).

Systemic Candida albicans infection was diagnosed in two adult alpaca stallions originating from different herds. Case 1 had a history of chronic dermatitis with unknown aetiology that had been treated long-term with glucocorticoids. Case 2 had suffered from transient facial paralysis and psoroptic mange of the external ear. Both animals died suddenly after recovering from their initial disorders. Necropsy examination of case 1 revealed multifocal erosive dermatitis, thoracic and abdominal serofibrinous effusions, and multiple suppurative foci in lung, myocardium, kidney, pancreas and brain. Case 2 had multiple ulcers of the third gastric compartment and focal suppurative nephritis. Additionally, moderate depletion of lymphoid organs was observed in both animals. Histologically, suppurative to necrotizing inflammation with necrotizing vasculitis was present in the grossly affected organs of both animals. Yeast, pseudohyphae and branching hyphae were present within these lesions and C. albicans was isolated from lesional tissue of both animals. The primary site of Candida invasion was not determined in case 1, but the most likely portal of entry in case 2 was the gastric ulcers. Depletion of lymphoid tissue suggested a possible underlying immune suppression in both animals.