Strongyloides stercoralis is a soil-transmitted helminth that is increasingly reported in dogs across Europe. While most infections are subclinical, hyperinfection syndrome, marked by excessive larval proliferation and systemic spread, can occur in immunocompromised hosts. An 11-year-old male Boston Terrier dog, originating from southern France with a history of chronic diarrhoea and recent splenectomy was presented with severe regenerative anaemia, thrombocytopenia, and a degenerative left shift. Haemotropic Mycoplasma haemocanis infection was diagnosed, and doxycycline therapy was initiated. During hospitalisation, the dog developed dyspnoea, pneumonia, and progressive pleural effusion containing motile nematode larvae. Strongyloides stercoralis infection was diagnosed by morphological identification of larvae in pleural effusion (third-stage larvae) and faeces (first- and third-stage larvae) and confirmed by PCR targeting mitochondrial cox1 and nuclear 18S rDNA hypervariable regions (HVR) I and IV), followed by sequencing, which revealed the haplotypes HP16 (cox1), VI (HVR-I) and A (HVR-IV). The HVR-IV haplotype A is found in both dogs and humans, characterizing the zoonotic population of S. stercoralis. Respiratory signs worsened despite combined fenbendazole and escalating ivermectin treatment, requiring euthanasia. Post-mortem examination revealed chronic granulomatous pneumonia, a pulmonary carcinomatous nodule, lymphoplasmacytic enterocolitis, and glomerulonephritis. This case represents the first report of S. stercoralis hyperinfection in an adult splenectomised dog. It highlights the importance of including strongyloidiasis in differential diagnoses of dogs with respiratory and gastrointestinal signs, particularly in animals with compromised immunity or relevant travel history.

Strongyloides spp. infecting felids remain largely understudied. To date, four Strongyloides species have been reported in felids worldwide: S. felis, S. planiceps, S. stercoralis, and S. tumefaciens. Most epidemiological studies performed in felids identified the parasites only to genus level. This study aimed to determine the prevalence of Strongyloides spp. in domestic cats (Felis catus), free-ranging Eurasian lynx (Lynx lynx), and European wildcats (Felis silvestris) from Switzerland, while providing detailed morphological and molecular characterization of the parasites. A total of 490 intestinal content and faecal samples (172 domestic cats, 261 lynx, and 57 wildcats) were analysed using Baermann and sedimentation-flotation techniques. Morphological measurements of Strongyloides spp. eggs, larvae and adults were recorded. Molecular identification involved conventional PCRs targeting the 18S rRNA and cox1 gene fragments, followed by Sanger sequencing, Oxford Nanopore Technologies (ONT) deep amplicon sequencing and bioinformatic analysis. The coproscopical prevalence of Strongyloides spp. in wild felids was 9.6% (25/261) in lynx and 7% (4/57) in wildcats, whereas in domestic cats it was 0.6% (1/172). All positive samples contained free first-stage rhabditiform larvae. Eight lynx samples additionally had larvated eggs and in three lynx and one wildcat, also rhabditiform adults were present. Morphological features were consistent with S. planiceps. Sanger sequencing mostly failed. ONT sequencing and phylogeny confirmed S. planiceps in 16 representative samples (12 lynx, three wildcats, one domestic cat) and revealed high intraspecific variability in the cox1 gene. Additionally, S. ratti sequences were detected in one wildcat. This study represents the first prevalence study with molecular characterization in wild felid populations globally, and the first identification of S. planiceps in Europe. A higher prevalence was observed in wild felids than in domestic pet cats. ONT deep amplicon sequencing proved to be a robust tool for identifying Strongyloides species from complex samples, overcoming the Sanger sequencing limitations.

Angiostrongylus dujardini is a heteroxenous metastrongyloid nematode that primarily inhabits the pulmonary arteries and the right heart of murid and cricetid rodents and uses gastropods as intermediate hosts. Although not considered highly pathogenic for rodents, this parasite has been reported to cause death in callitrichid monkeys, suricates and a psittaciform bird under human care. In contrast to rodents, shedding of first-stage larvae (L1) in the faeces has not been documented in these species; consequently, they have been regarded as accidental hosts. This study reports fatal A. dujardini infections in seven cotton-top tamarins (Saguinus oedipus) from a Swiss zoological garden between 2005 and 2024, and L1 shedding in one of the individuals. Five monkeys were found dead without prior clinical signs, while two showed weakness shortly before death. Gross pathological findings at necropsy included dark red pulmonary discoloration, lung nodules, intrathoracic effusion, right heart dilation and subepicardial haemorrhages. Histopathological examination revealed multifocal collection of thin-walled, embryonated nematode eggs at variable stages of development, along with fully developed larvae within the lumina of alveoli and pulmonary vessels, surrounded by granulomatous inflammation, consistent with granulomatous pneumonia and endarteritis in all cases. In the most recent fatal case, A. dujardini L1 were detected in the faeces, providing evidence that S. oedipus can act as a definitive host of this parasite, capable of environmental contamination. The diagnosis of A. dujardini infection was achieved by histopathological and molecular investigations of lung tissues and faecal larvae. This is the first report of A. dujardini infection with larval shedding in a non-human primate, confirming their role as potential definitive hosts, and underlining the need for heightened parasitological surveillance in captive primate populations.

Protozoa of the genus Sarcocystis have an obligate two-host-prey-predator life cycle, in which South American Camelids (SAC) are among the intermediate hosts for certain species. Sarcocystis spp. infection has been well documented in SAC in endemic areas of the South America, while data from Europe are absent. This study assessed the seroprevalence of Sarcocystis spp. in SAC in Italy investigating related risk factors. A total of 506 SAC sera (486 alpacas and 20 llamas) from 38 sampling sites were analysed to detect antibodies to Sarcocystis spp. using the Indirect Fluorescent Antibody Test (IFAT). A seropositivity of 15.2% (77/506) was found, corresponding to 14.4% (70/486) in alpacas and 35.0% in llamas (7/20). Risk factor analysis showed that Sarcocystis spp. seropositivity increased with age, while no statistically significant association was found with regard to sex. Access to stables and/or pasture by dogs was identified as a putative risk factor, particularly as the number of dogs increased. Further association was found between seropositivity to Sarcocystis spp. and N. caninum. Although the life cycles of Sarcocystis spp. in SAC are not fully elucidated, these findings highlight the need for further studies to clarify the potential role of dogs as definitive hosts for Sarcocystis species infecting SAC in Europe. This study provides for the first time data on specific antibodies for Sarcocystis spp. in SAC in Europe, highlighting the need of improving the surveillance of this protozoan in camelids, particularly given the growing interest in camelid meat production.

Health monitoring based on post-mortem examination is essential for the management of endangered animal species. This is especially true for reintroduced species living in small populations with low genetic diversity, such as the Eurasian lynx (Lynx lynx) in Switzerland. Thanks to systematic post-mortem examinations, the Institute for Fish and Wildlife Health (FIWI), University of Bern, has acquired a comprehensive view of the lynx health in Switzerland. This study provides an updated overview of the causes of morbidity and mortality in the Eurasian lynx in Switzerland from 2000 to 2022. A total of 346 necropsied lynx (found dead, euthanized, or culled) were included in this study, and a cause of death (COD) was identified in 318 of them (91.9%). Overall, the main COD was blunt trauma (n = 183, 52.9% - largely vehicular collision). Starvation, resulting from the separation of dependent juveniles from their mother, was the second most frequent COD (n = 63, 18.2%). Fatal infectious diseases were relatively low (n = 32, 9.2%). However, we documented some significant pathogens such as canine distemper virus (CDV) and metastrongyloid nematodes. Illegal killing was confirmed in 23 cases (6.6%). Of note, illegal killing is likely underestimated in this study, given that radio-collared lynx were found to be proportionally more often illegally killed than the unmonitored ones found by chance. Furthermore, most individuals were found to be affected at least by one non-specific, mild to moderate inflammatory process of unknown origin, such as interstitial pneumonia (n = 59) or interstitial nephritis (n = 25). Additionally, cardiac changes of variable severity were observed in 125 lynx, and severe soft tissue mineralization was detected in 10 individuals. The frequency of these findings warrants further investigation. Thus, this study confirms the importance of systemic post-mortem examination and general health surveillance of free-ranging Eurasian lynx in Switzerland, in support of translocation projects, conservation of the species, and to provide a better understanding of their pathologies.

Sarcocystis species are apicomplexan protozoa infecting a wide range of domestic and wild animals, including cattle, in which several species are of zoonotic relevance. This study reports, for the first time, the detection and molecular identification of pathogenic and zoonotic Sarcocystis hominis in slaughtered cattle from Central Chile. A total of 200 muscle samples (100 = myocardium, 100 = diaphragm) were examined by macroscopic inspection and tissue homogenization. Selected samples were additionally analyzed by histology, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and multiplex real-time PCR targeting the 18S rDNA. No macroscopic sarcocysts were observed, nonetheless microscopic sarcocysts were detected in 56% of assessed samples, with higher infection rates in the heart (91%) than in the diaphragm (21%). SEM and TEM analyses revealed thin-walled sarcocysts with finger-like protrusions in the diaphragm, as well as flattened hair-like projections in the myocardium. Molecular analysis identified Sarcocystis cruzi in all positive samples and detected additional DNA of Sarcocystis bovifelis/Sarcocystis rommeli and for the first time the zoonotic species S. hominis. These findings confirm the coexistence of canine-, feline-, and human-transmitted Sarcocystis species in Chilean cattle and highlight potential public health implications associated with consumption of raw or undercooked S. hominis-carrying beef meat. This constitutes the first molecular evidence of S. hominis in Chile, emphasizing the need for further surveillance and control measures in the meat production chain. These novel data on human S. hominis infections in Chile confirm the importance of initiating investigations on human sarcocystosis as this enteric parasitic disease is still sparsely considered by local public health authorities.

The recent global expansion of alpaca breeding, including in Italy, has driven growing interest in this species, making further research necessary to support their health and management. Gastrointestinal helminths are among the main health concerns, causing severe disease that affects welfare and productivity. In Europe, data on helminth infections in South American Camelids (SACs) are still limited. This study aimed to assess the prevalence, distribution, and risk factors for helminth infections in alpacas in Italy, and evaluate the husbandry and worm control practices through a structured questionnaire and coprological analyses. Individual fecal samples were collected from 1296 alpacas and analysed by the Mini-FLOTAC, Baermann, and sedimentation techniques. Gastrointestinal strongyle (GIS) type eggs were the most frequently detected helminths (54.0 %), followed by Nematodirus spp. (21.2 %), Trichuris spp. (12.6 %), Nematodirus battus (7.6 %), Capillaria spp. (6.7 %), Moniezia spp. (3.2 %), Dicrocoelium dendriticum (2.5 %), Strongyloides spp. (0.5 %), and Dictyocaulus spp. (0.2 %). Alpacas < 2 years were at higher risk of infection for all helminth groups. Breeding in central, southern, and insular area was significantly associated with almost all helminth infections. The warm season was significantly associated with GIS, Nematodirus spp., and Trichuris spp. infections. Alpacas with a BCS < 3 had a higher risk for Trichuris spp. and Capillaria spp. infections. Questionnaire responses (n = 104) revealed great attention to dung removal and parasitological monitoring. This study provides the first data on helminth infections in alpacas in Italy, showing wide species diversity. The use of fenbendazole and ivermectin was widespread, raising concerns about potential anthelmintic resistance.

The protozoan parasite Neospora caninum is an important cause of abortion in cattle. Infection occurs horizontally by ingestion of oocysts shed by canids or vertically, from an infected dam to the foetus, and may result in abortion, stillbirth, or the birth of subclinically infected offspring. We estimated the occurrence of N. caninum infections in cattle farms with repeated abortions in the canton of Grisons, Switzerland, by serological and molecular methods and investigated risk factors for infection. From March 2021 to March 2022, all available samples (serum/placenta/foetal brain) from cattle, which aborted during this period, were submitted to the Cantonal Veterinary Laboratory for mandatory abortion diagnostic and were additionally tested for N. caninum antibodies (ELISA), or DNA (real-time PCR). Two questionnaire surveys were conducted i) to collect farm and husbandry data for risk factor analysis, and ii) to assess the impact of diagnosis in positive farms and the outcome of control measures. Overall, 488 cattle from 356 farms were tested (488 sera, 247 placentas, 98 foetal brains). Seroprevalence at animal level was 11.3 % (54/488), whereas at herd level it was 14.0 % (50/356). Eighteen (69 %) out of 26 placentas from seropositive dams were PCR-positive. Vertical transmission was confirmed by PCR on foetal brain in 87 % (13/15) of seropositive dams from which this sample was available. All placenta and foetal samples from seronegative cattle were PCR negative. The response rates of the first and second questionnaires were satisfactory with 40.4 % (659/1632) and 46 % (23/50) responding farms, respectively. Due to the low prevalence of infection, no risk factors could be inferred. The second survey revealed that owners of positive farms appreciated the surveillance of N. caninum and requested increasing awareness among dog walkers about the contamination of pastures with dog faeces and the provision of subsidies for prevention and control measures.

Taenia crassiceps, a cestode cycling between canids and rodents, poses a significant threat to zoo-kept primates, which are highly susceptible to severe cysticercosis. Fenbendazole is commonly used for treatment, though efficacy varies with lesion severity and localization of the disease-causing metacestode. In this study, T. crassiceps metacestodes, molecularly confirmed, were obtained from skin lesions collected from a Lemur catta that died at Zoo Salzburg. Parasites were cultured and treated with standard anthelmintics - albendazole, fenbendazole, mebendazole, and praziquantel - at 40 μM to evaluate in vitro efficacy. Young (1-week) and old (17-week) cultures were used to asses drug efficacy by damage-marker release assay measuring the release of phosphoglucose isomerase (PGI) after 5 and 12 days. An automated assay measured motility reduction. Both drug testing methods were adapted from a well-established in vitro system for Echinococcus, enabling future cross-species comparisons. Praziquantel showed the most pronounced effect on parasite integrity after 12 days (29 % PGI release versus detergent control) and completely halted motility. Benzimidazoles were less effective when tested at same concentrations. Albendazole and mebendazole showed moderate PGI release (14 %), while fenbendazole showed none. Among benzimidazoles, mebendazole reduced motility most (49 %), followed by albendazole (56 %) and fenbendazole (87 %). We successfully adapted in vitro screening methods for T. crassiceps metacestodes using established techniques for Echinococcus. Although not aimed at identifying alternative treatments, findings suggest praziquantel - alone or with mebendazole - may offer more effective management for T. crassiceps in zoo primates than fenbendazole alone until better therapies become available.

Canine hepatozoonosis is caused by the tick-borne protozoans Hepatozoon canis and Hepatozoon americanum (Apicomplexa, Hepatozoidae). While H. americanum is widespread in the south-central and south-eastern United States, H. canis is documented in Europe, Africa, Asia, and South America, and is transmitted to dogs by ingesting infected ticks, primarily Rhipicephalus sanguineus. In Europe, this vector is mainly distributed in the Mediterranean region but endemic areas within Central Europe have also been reported, possibly facilitated by climate change. A mixed-breed male puppy, ∼3-7 months-old, evacuated from Kherson City, Ukraine, was admitted to a private veterinary clinic in Kyiv in August 2023. There was no information about the owner and history of the animal. Physical examination evidenced fever, anorexia, lethargy, mild dehydration, and pale mucous membranes. Alopecia, purulent skin ulcers, and pruritus were also observed. On day 1 of admission, a 34 % hematocrit and elevated leukocyte counts, particularly granulocytes and lymphocytes, were observed. H. canis gamonts were detected in stained blood smears and confirmed by specific PCR. Treatment was initiated with imidocarb at 6.6 mg/kg i.m. at 15-day intervals for six weeks, and doxycycline 10 mg/kg orally once daily for two weeks. Blood counts improved between towards day 16, with initial increase and subsequent normalization of hematological parameters. Hepatozoon-PCR was still positive on day 16. The dog made a full recovery, and no further tests were done thereafter. The systemic clinical signs were likely parasite-induced. H. canis and its vector R. sanguineus are being increasingly reported in Europe outside of their original geographical distribution, the Mediterranean basin. This case confirms the geographical expansion of this protozoan parasite.

Sarcocystis spp. and Toxoplasma gondii are heteroxenous protozoan parasites, which form cysts in muscle tissue of intermediate hosts (IH) and oocysts in the intestinal mucosa of definitive hosts (DH). Wild boars (Sus scrofa) are IH for Sarcocystis miescheriana (with wild and domestic canids as DH), S. suihominis (with humans and non-human primates as DH) and T. gondii (with felids as DH). The aim of this study was to identify and characterize Sarcocystis spp. and T. gondii in the muscle tissue of wild boars hunted and/or consumed in Switzerland. DNA was extracted from muscle samples of 286 wild boars and tested by PCRs targeting the 18S rRNA gene of Sarcocystis spp., the mitochondrial cytochrome c oxidase (cox1) gene of S. suihominis and by a qPCR targeting a 529 bp genomic repeat of T. gondii. Besides, 225 samples were processed by homogenization and direct microscopic examination and 42 samples by histopathology. Sarcocysts were detected microscopically in 89.3 % (201/225) and 35.7 % (15/42) of the samples, respectively. The 18S rRNA PCR detected parasite DNA in 91.3 % (261/286) of the samples, and all 62 sequences obtained were 100 % identical, and also with GenBank sequences reported as S. miescheriana, suggesting a high environmental contamination with canid faeces. The S. suihominis-cox1 PCR was positive in 1.75 % of the samples (5/286), and the six cox1 sequences (772 bp primers trimmed) obtained were 97.3-99.6 % similar among them and 97.7-100 % identical with a sequence reported as S. suihominis. Despite the identity differences, all these sequences were grouped together in a phylogenetic tree, in a sister clade of S. miescheriana sequences. All samples tested negative for T. gondii by qPCR. This study revealed for the first time the presence of S. suihominis in wild boars hunted in Switzerland.

A six-year-old mixed-breed female hunting dog, which has been imported from Bulgaria to Germany, was admitted to a private veterinary clinic presenting a swelling (approx. 10 ×10 x 1 cm) with ulceration of the skin on the left abdominal flank. The dog evidenced difficulty to climb the stairs. The mass including skin and subcutaneous tissues was surgically removed and submitted for routine histological examination. Microscopically, a severe pyogranulomatous to mixed-cellular and lymphoplasmacytic inflammation, with demarcating fibrosis, involving cutis, subcutis and cutaneous muscle was observed. Multiple cyst-like structures (∼0.25 mm diameter) with an eosinophilic hyalinised wall, containing nematode larvae sections (∼26 µm wide) were detected intralesional, and a Trichinella infection was suspected. Consequently, DNA was extracted from formalin-fixed paraffin-embedded tissues and a multiplex PCR for Trichinella species/genotype identification was performed. After electrophoresis, two bands of 129 and 253 bp were observed, which corresponds to the banding pattern of T. britovi. Trichinella T8 and T9 show a similar banding pattern; however, these genotypes are assumed to exclusively circulate in sub-Saharan Africa and Japan, respectively. The localisation of Trichinella in the cutaneous muscle, and the high degree and extension of inflammatory reaction observed are unusual. Consumption of hunted prey was assumed as the most probable source of infection. Trichinella spp. should be considered in the differential diagnosis of nematodes, which may be observed in cutaneous and muscular biopsies in dogs.

Eurasian wolves (Canis lupus lupus) and domestic dogs (Canis lupus familiaris) are definitive hosts of numerous cestode species. While infections with adult stages in canids are usually subclinical, some species pose a zoonotic risk or cause infections in wildlife and livestock, resulting in disease and/or economic losses. This study aimed to determine the prevalence, species composition, and geographical distribution of cestode infections in dogs and free-ranging wolves in Switzerland. Faecal samples from 2,065 dogs and intestinal content from 121 necropsied wolves were macroscopically examined and tested using zinc chloride flotation method. When cestode eggs or adult cestodes were detected, a molecular identification based on multiplex-PCR and sequencing was performed. In the sampled wolves, the prevalence by flotation (42/121; 34.7%) was lower than the overall prevalence including macroscopic examination (76/121; 62.8%). The flotation method thus failed to detect cestode infections in 44.7% (34/76) of infected wolves. The most frequently detected species was Taenia hydatigena (46/121; 38.0%), followed by Taenia serialis (23/121; 19.0%), Mesocestoides spp. (3/121; 2.5%), Taenia ovis (1/121; 0.8%), and Echinococcus multilocularis (1/121; 0.8%). In the analysed dogs, the prevalence was 0.9% (19/2,065), but the real prevalence is very likely to be higher, as no necropsy data were available. Identified cestode species included Taenia crassiceps (6/2,065; 0.3%), E. multilocularis (3/2,065; 0.1%), Mesocestoides sp. (2/2,065; 0.1%), Taenia polyacantha (1/2,065; 0.05%), and Dibothriocephalus latus (1/2,065; 0.05%). By identifying the cestode species infecting two closely related host species with markedly different lifestyles, this study sheds light on the local distribution of these parasites and their potential impacts on wildlife, livestock, and human health. Due to their close contact with humans, infected dogs represent an important source of infection with zoonotic cestodes such as Echinococcus spp. and certain Taenia species, responsible for serious human diseases.

Besnoitia spp. are cyst-forming Apicomplexa parasites within the Sarcocystidae family. The objective of this study was to identify Besnoitia spp. in synanthropic (Muridae) and wild (Cricetidae) rodents from Argentina. Samples were collected from different organs and tissues of 356 rodents and examined by histopathological methods. Besnoitia cysts were detected by histopathology in 2 % (7/356) of the animals (i.e., two Mus musculus, two Necromys spp., two Oxymycterus rufus, and one Akodon azarae). The morphological diagnosis was molecularly confirmed by PCR and bidirectional sequencing of the ITS1 marker and flanking regions. The complete ITS1 region was identical in all seven samples, exhibiting 100 % identity with Besnoitia akodoni (AY545987). In addition, further characterization of the isolates targeting 18S rRNA and CoxI gene fragments was performed. Five identical 18S rRNA consensus sequences were amplified, which matched 100 % with Besnoitia sp. from Abrothrix hirta (Chile; OR052141) and B. jellisoni (AF291426) sequences. Besides, three CoxI consensus sequences were obtained from three different rodent species. These were identical among them and showed 92.88-92.93 % similarity to sequences from Besnoitia besnoiti uncharacterized protein (XM_029362743, among others). This is the first study to identify B. akodoni in naturally infected murid (Mus musculus) and cricetid (Necromys spp., Oxymycterus rufus, and A. azarae) rodents from Argentina, using both histopathological and molecular assessment. Further research is necessary to elucidate the significance of this parasite in rural ecosystems in our country.

Hepatozoon spp. are increasingly reported in cats from Mediterranean countries, but data for Central and Northern Europe remain limited. This study investigated the occurrence and molecular diversity of Hepatozoon spp. in 1357 blood samples from cats living in Germany and other European countries using real-time PCR targeting the 18S rRNA gene. Hepatozoon spp. DNA was detected in 58 cats (4.3 %; 95 %-CI: 3.3-5.5 %). Thirty-seven positive samples were further analyzed by conventional PCR and sequencing. Four sequence types (A-D) were detected. Hepatozoon felis sequences classified within the genogroup I (types A and B) were identified in 33 cats; Hepatozoon silvestris haplotype I (type C) in one cat; and sequences showing 98.5 % identity to H. silvestris (type D) in three cats. Younger cats had a significantly higher infection risk (p = 0.026), while no association with sex was found. Samples submitted for targeted Hepatozoon testing and travel disease screening showed higher positivity rates. Among the 37 molecularly characterized cases, 31 had a known import origin, primarily from Greece, Spain, Cyprus, Italy, Bulgaria, the United Arab Emirates, Jordan, and Turkey. Notably, the H. silvestris-positive cat from Austria had no travel history, representing the first autochthonous case in a domestic cat in Austria. This study highlights the emergence of feline Hepatozoon infections in Europe, involving genetically diverse species. Infections should be considered mainly in cats with Mediterranean origin, travel history, outdoor access, or tick exposure. Identifying vectors responsible for transmission is crucial for implementing effective prevention strategies.

Hippoboscidae diptera or louse flies are widely distributed blood-feeding ectoparasites that can transmit blood parasites to their host. Four species are recognized within the Crataerina genus, which are parasites of the bird orders Apodiformes and Passeriformes. Alpine swifts (Tachymarptis melba) are frequently parasitized by Crataerina louse flies during the nesting season. In Switzerland, an increase in Alpine swift nestling mortality has been associated with a Trypanosoma sp. infection. In this study, fixed and native specimens of Craterina louse-flies collected from Swiss Alpine swifts were analysed to reveal the species identity based on morphotypes and PCR-sequencing, and examined for the presence of Trypanosoma sp. using microscopy and PCR. Morphologically, all specimens belonged to the genus Crataerina. Based on wing types, both C. melbae and C. acutipennis, as well as mixed morphotypes, were recorded. Sequencing based on the cytochrome-oxidase 1 (COI) gene of 24 flies confirmed the presence of previously defined haplotypes of C. melbae and suggest that the morphotypes C. melbae and C. acutipennis likely constitute a single species. One louse-fly specimen was processed by scanning electron microscopy and elongated organisms resembling trypanosomes were observed on the ventral abdominal surface. Dissected intestines and abdominal surface swabs resulted positive by Trypanosoma sp. PCR. Microscopy of native specimens evidenced motile and actively multiplying trypanosomes in the midgut and rectum. All Trypanosoma sp. sequences from louse flies were identical to those obtained from tissues of infected Alpine swifts. This study suggests that C. melbae is a single species infecting Alpine swifts, regardless of the wing morphotype or sequence type, and that C. melbae acts as a competent vector for Trypanosoma sp. associated with nestling mortality. Further studies should be focused on environmentally sustainable ways to control C. melbae, with the goal to minimize transmission and the impact of trypanosomiasis in Alpine swift populations.

Wolves (Canis lupus lupus) and lynx (Lynx lynx) are officially monitored species in Switzerland. Deceased individuals are subjected to post-mortem examination and collection of baseline health data. The procedure includes an assessment of different infectious agents, including Trichinella spp., the cause of a notifiable zoonotic infection. Between May 2009 and May 2023, a total of 100 wolves and 250 lynx were tested at the National Reference Laboratory for Trichinellosis by the artificial digestion method. Additionally, muscle samples from 8838 wild boars (Sus scrofa), 27 red foxes (Vulpes vulpes), and 23 European badgers (Meles meles), mainly submitted by Swiss hunters, were also analysed for Trichinella infection. Trichinella spp. larvae were detected in 16/100 (16 %) wolves, 41/250 (16.4 %) lynx, 2/27 (7.4 %) red foxes, 0/23 (0 %) badgers, and 1/8838 (0.01 %) wild boars. All positive samples were further tested by multiplex PCR to identify the parasite at the species/genotype level. Two species were detected: T. britovi (in 14 wolves, 33 lynx, 2 red foxes and 1 wild boar) and T. spiralis (in one lynx). In nine cases, the molecular identification was not possible. Although no cases of Trichinella spp. infection in domestic swine and horses were detected in the last decades in Switzerland, we revealed that these parasites, most frequently T. britovi, are still present in Swiss wildlife. Therefore, inspection of game meat remains very important, and the occurrence of sporadic infection in domestic animals cannot be excluded.

Rodents serve as reservoir hosts for many parasites, including the closely related intracellular protozoan parasites Toxoplasma gondii and Neospora caninum, which are regarded as major causes of abortion in ruminants. This study investigated T. gondii and N. caninum infections in synanthropic (Muridae) and wild (Cricetidae) rodents from rural areas in the Pampas Region, Argentina, using histological, serological, and molecular methods. We also genetically characterized T. gondii isolates. A total of 356 rodents were captured, comprising both murid (Mus musculus, Rattus norvegicus, R. rattus) and cricetid (Oxymycterus rufus, Necromys spp., Akodon azarae, Oligoryzomys flavescens, Calomys musculinus, C. laucha) species. Histological examination did not reveal tissue cysts of these parasites. However, antibodies for T. gondii and N. caninum were detected in 9.8 % (35/356) and 1.7 % (6/356) of the samples using the indirect immunofluorescent antibody test (IFAT). T. gondii DNA was detected by qPCR in brain samples from two of the 41 seropositive rodents. Multilocus PCR-RFLP revealed atypical T. gondii genotypes in both samples. N. caninum DNA was not detected by PCR in any sample. This study provides the first serological and molecular evidence of T. gondii and N. caninum in Cricetidae rodents from Argentina, including the first genotyping data. The detection of T. gondii DNA exclusively in wild rodents highlights the role of wildlife in parasite transmission.

Sarcocystis spp. (Apicomplexa: Coccidia) are obligate heteroxenous protozoa that infect a wide range of host species. Transmission follows a predator-prey cycle involving an intermediate host (IH) and a definitive host (DH). For many species, only IHs have been identified, while DHs remain unknown. DHs can be infected with multiple Sarcocystis spp. at the same time, which complicates species identification. We aimed to determine the prevalence and species diversity of Sarcocystis infections in free-ranging wolves in Switzerland using both coprological and molecular methods. A further goal was to evaluate the utility of Third-generation sequencing for resolving mixed infections. A total of 87 wolf intestinal content samples were collected between 2017 and 2023 and analyzed coproscopically by a sedimentation-flotation method. Sarcocystis oocysts/sporocysts were detected in 76 % (66/87). DNA was obtained from 57/66 positive samples and 55/57 resulted positive in a Sarcocystis 18S rRNA screening PCR. Additionally, mitochondrial cytochrome c oxidase subunit I (COI) gene PCR and a real-time PCR targeting S. cruzi were performed. PCR products from conventional PCRs were submitted for Sanger sequencing. Monoinfections were identified in 16 % (9/55) and mixed infections in 84 % (46/55) of the samples. A subset of five samples was analyzed by Third-generation sequencing (Pacific Biosciences) of the 18S rRNA full-length and COI fragment PCR products. BLAST and phylogenetic analysis were used to validate taxonomic classification. Molecular analysis identified nine known Sarcocystis species: S. tenella, S. arieticanis, S. capreolicanis, S. linearis, S. gracilis, S. cruzi, S. capracanis, S. iberica, and S. venatoria. Newly developed pipelines for the Third-generation sequencing data provided high-resolution species-level identification in samples with mixed infections. These findings confirm the Eurasian wolf as natural DH for multiple Sarcocystis species for the first time, including S. linearis, S. iberica, and S. venatoria. Further complementary studies on prey species are needed to clarify host-parasite dynamics.