Cardiopulmonary parasitic nematodes of the red fox (Vulpes vulpes) in Serbia.

Among the wild canids, the red fox (Vulpes vulpes) is recognised as an important reservoir species for a range of parasites, including cardiopulmonary nematodes of public health and veterinary importance. As cross-host transmission between the red fox and domestic carnivores can play an important role in the epizootiology of cardiopulmonary parasitic diseases, the aim of the present investigations was to obtain data on the geographical distribution of cardiopulmonary nematodes of the red fox. The material for examination consisted of 83 foxes which were legally hunted at different locations during a three-month period from December 2017 to February 2018. The presence of four emerging species in Europe (Angiostrongylus vasorum, Crenosoma vulpis, Dirofilaria immitis and Eucoleus aerophilus) was revealed in red foxes of Serbia. Crenosoma vulpis and E. aerophilus were detected in foxes in both the plain and the mountainous areas across the country. Dirofilaria immitis is distributed in red foxes near alluvial rivers in Vojvodina province (northern Serbia). Angiostrongylosis caused by A. vasorum was demonstrated to exist in two enzootic foci with a high percentage of infected foxes in a plain area of northern Serbia. To the best of our knowledge, C. vulpis and A. vasorum were discovered for the first time in red foxes in central Serbia. The results provide strong evidence for veterinarians to take into consideration the parasitic nematodes discovered in red foxes in the differential diagnosis of diseases of companion animals. In the context of the 'One Health' approach the results related to the distribution of the zoonotic species E. aerophilus and D. immitis can be useful for medical epidemiology.

Simultaneous detection of vaccinal and field infectious bursal disease viruses in layer chickens challenged with a very virulent strain after vaccination.

Infectious bursal disease virus is an important poultry pathogen. It is distributed worldwide and causes significant economic losses. In this study, a system was adopted for the simultaneous monitoring of vaccine and virulent strains using reverse transcription polymerase chain reaction (RT-PCR). After the decay of maternal antibodies, chickens were vaccinated at the age of 37 days with a virus of intermediate virulence and challenged at 5, 10 and 14 days post vaccination (dpv). The challenge was done with IBDV strain CH/99. Sequencing of the hypervariable region of VP2 has shown that CH/99 belongs to the very virulent group of viruses. The vaccine virus could be found in the bursa of Fabricius, spleen, thymus and bone marrow until 24 dpv. The CH/99 challenge virus was found in the bursa and lymphoid organs when chickens were challenged at 5 and 10 dpv. When challenge was performed at 14 dpv, the pathogenic virus could not be found in the bursa and other lymphoid organs.

Are golden jackals (Canis aureus) definitive hosts for Angiostrongylus vasorum?

Angiostrongylosis caused by Angiostrongylus vasorum is an emerging disease in Europe. Recent reports have shown that, besides the red fox (Vulpes vulpes) recognized as the main definitive host and reservoir for the parasite, the role of the definitive host can be taken by a range of mammals. We considered that, due to the rapid large-scale expansion of its populations in Europe, the golden jackal (Canis aureus) could assume an important role in the epidemiology of the disease. The aim of the investigations was to explore the role of the golden jackal as the definitive host for A. vasorum. Sixty-three golden jackals, legally hunted in lowlands around the Danube River in Serbia recognized as the core area of the species' distribution in Europe, were subjected to patho-morphological and parasitological examination. The adult forms of A. vasorum were detected in the pulmonary arteries in six golden jackals with gross lesions manifested in the lungs. The finding of first stage larvae (L1) of A. vasorum in microscopic smears of the lung tissue altered by infection, which was consistent with the presence of adult parasites and manifestation of gross lesions in the lungs, confirms the successful reproduction of the parasite in the golden jackal. Migration of L1 from the blood vessels to the airways was confirmed by histopathology and, subsequently, their shedding was demonstrated by the Baermann method. The results support the hypothesis that the golden jackal acts as a suitable definitive host for A. vasorum. As a definitive host with a large-scale expansion of its populations in Europe, the golden jackal may be an important part of the parasite's host repertoire by spreading the parasite into previously non-endemic areas and by being an additional definitive host in endemic areas of vulpine angiostrongylosis.