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Abstract Background Dirofilariosis is a parasitic mosquito-borne disease caused by members of the genus Dirofilaria, which includes Dirofilaria immitis and Dirofilaria repens. Surveillance studies in Europe have revealed that D. immitis can also be detected in a range of wild carnivores, raising questions over the impact of infections on wild carnivore animal health but also whether these populations may act as a reservoir for infection of other species, including domestic dogs and humans. Methods In the current study, we conducted surveillance for the presence of D. immitis in several wild carnivore species, including golden jackals (Canis aureus; n = 77), red foxes (Vulpes vulpes; n = 326), and European badgers (Meles meles; n = 28), collected during an annual rabies surveillance and control program from across continental and coastal regions of Croatia. Results Macroscopic examination of the right chambers of the heart during a post-mortem examination resulted in the detection of filarial parasites in 6.5% (5/77) golden jackal carcasses. Morphological identification, confirmed by molecular screening, classified all parasites as D. immitis. No D. immitis were detected in the red foxes or European badgers examined. All infected golden jackals were adults aged from 2 to 7 years with a parasite load ranging from 2 to 7 nematodes per carcass. One animal was infected with a sexually mature pair, while a second harbored pre-mature parasites; the remaining positive jackals were infected with female parasites only. Notably, histological examination of cardiac and lung tissue revealed proliferative endarteritis in the jackal with the highest parasite burden. Conclusions Further studies are required to establish whether golden jackals, as well as other wild carnivore hosts, may serve as competent definitive hosts of D. immitis and act as reservoirs for infection of other species including domestic dogs and humans. Histological changes in the cardiac tissue of at least one positive jackal were suggestive of infection with pathological consequences for the host. Graphical Abstract

The infestation of ruminants by fly larvae of the Oestridae family can lead to nasopharyngeal or subcutaneous myiasis, which can harm animal welfare and productivity on sheep and cattle farms. The infestation of wild ruminants allows them to serve as reservoirs for subsequent transfer to domestic animals. The fly species most commonly responsible for myiasis have been well studied in many parts of the world, but less so in southeastern Europe. Here, we identified three botfly species among 197 subcutaneous larvae and 138 nasopharyngeal larvae from 36 wild roe deer (Capreolus capreolus) and 9 wild red deer (Cervus elaphus) at 30 locations across Croatia. Instars were stored in 75% ethanol and their species and developmental stage were identified based on morphological and morphometric keys. Subcutaneous larvae in both cervid species were identified as Hypoderma diana, while nasopharyngeal larvae were identified as Cephenemyia simulator in roe deer and Pharyngomyia picta in red deer. Partial sequencing of the gene-encoding mitochondrial cytochrome oxidase subunit I confirmed the taxonomic classification of C. stimulator and P. picta but was unable to confirm that of H. diana for lack of previously published sequences. This study appears to be the first to combine the morphological and molecular characterization of myiasis-causing botflies in wild cervids in southeastern Europe.

Abstract Ixodid ticks are distributed across all countries of the Western Balkans, with a high diversity of species. Many of these species serve as vectors of pathogens of veterinary and medical importance. Given the scattered data from Western Balkan countries, we have conducted a comprehensive review of available literature, including some historical data, with the aim to compile information about all recorded tick species and associated zoonotic pathogens in this region. Based on the collected data, the tick fauna of the Western Balkans encompasses 32 tick species belonging to five genera: Ixodes, Haemaphysalis, Dermacentor, Rhipicephalus and Hyalomma. A range of pathogens responsible for human diseases has also been documented, including viruses, bacteria and parasites. In this review, we emphasize the necessity for integrated surveillance and reporting, urging authorities to foster research by providing financial support. Additionally, international and interdisciplinary collaborations should be encouraged that include the exchange of expertise, experiences and resources. The present collaborative effort can effectively address gaps in our knowledge of ticks and tick-borne diseases. Graphical Abstract