Two cases of Angiostrongylus vasorum, a cardiopulmonary nematode, in a wild black bear and coyote of Tennessee.

Angiostrongylus vasorum, commonly known as the French heartworm, is a metastrongyloid parasitic nematode that infects wild and domestic canids. In North America, A. vasorum is endemic to the Canadian island of Newfoundland, but has been expanding to new areas including Nova Scotia, Prince Edward Island, and West Virginia (USA). Two cases of A. vasorum are reported from the state of Tennessee. The first case in a black bear (Ursus americanus) and the second case in a coyote (Canis latrans). The black bear was found dead in Sevier County in November of 2022, while the coyote was trapped and euthanized as part of a predator control program in Campbell County in January of 2023. Histology of the lungs revealed both animals had verminous pneumonia. DNA was extracted from the lungs of both, and PCR was performed using NC1 and NC2 primers. Sequencing results of the PCR products from the bear and coyote samples indicated that they were 95% and 96% similar, respectively, to European strains of A. vasorum. This report marks the first time A. vasorum has been reported in Tennessee as well as only the second and third report of autochthonous A. vasorum infection in the United States and the first report in an ursid. These two cases confirm the spread of A. vasorum further into North America. This nematode is highly pathogenic to wild and domestic canids, and thus these cases represent an emerging threat to both and underscore the need for further surveillance for the parasite.

First autochthonous case of Angiostrongylus vasorum in a domestic dog in the United States.

OBJECTIVE: To describe the clinical presentation, diagnostic findings, and medical management of the first suspected autochthonous case of a dog in the US diagnosed with Angiostrongylus vasorum, the French heartworm. ANIMAL: A 10-month-old Goldendoodle born in Oregon and residing in Washington State. CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES: The dog presented for evaluation of intermittent vomiting and diarrhea. Bloodwork revealed leukocytosis with mild lymphocytosis, monocytosis, eosinophilia, and basophilia. Larvae were detected on a fecal flotation, and fecal PCR confirmed A vasorum. TREATMENT AND OUTCOME: Administration of milbemycin oxime PO once a week for 4 weeks was initiated with recommendation to continue monthly treatment at label dose. The patient improved over the course of treatment. CLINICAL RELEVANCE: This case highlights the clinical and diagnostic findings and medical management of A vasorum, also known as the French heartworm, in a dog in the US. Few cases of A vasorum have been reported in wild foxes in North America, mostly in eastern Canada and 1 within the eastern US. Here we report for the first time an autochthonous case of A vasorum in a domestic dog in the US and the first report of any canid in the western US. This case highlights the importance of considering A vasorum as a differential for respiratory disease, gastrointestinal disease, or inexplicable eosinophilia in canine veterinary patients in the US and raises awareness for veterinary practitioners to incorporate appropriate preventative and diagnostic measures for their canine patients.

An in vitro larval motility assay characterizes anthelmintic efficacy against Crenosoma vulpis, Angiostrongylus vasorum, and Aelurostrongylus abstrusus.

OBJECTIVE: This study determined the in vitro efficacy of 6 common anthelmintics (eprinomectin, ivermectin, milbemycin oxime, moxidectin, selamectin, and fenbendazole) on motility (viability) of infectious third-stage larvae (L3) of Crenosoma vulpis, Angiostrongylus vasorum, and Aelurostrongylus abstrusus, which are important causes of canine and feline cardiopulmonary disease. SAMPLES: First-stage larvae (L1) from C vulpis, An vasorum, and Ae abstrusus. PROCEDURES: Naïve Limax maximus slugs were fed 1,000 to 2,000 L1 and held at 16 °C for at least 4 weeks to produce live L3. Approximately 50 to 100 L3/well were subsequently incubated in culture media alone or media containing 6 separate test anthelmintics at 4 concentrations, to bracket expected in vivo drug plasma levels in anthelmintic-treated dogs and cats. Drug effects on L3 motility (viability) were analyzed by multilevel logistic models, generating dose-response relationships. Experiments were completed 1-9/2019. RESULTS: Drug concentration estimates corresponding to a 50% larval mortality rate identified that C vulpis was the most sensitive species to the anthelmintics tested. Ae abstrusus was most susceptible to moxidectin and selamectin, while An vasorum was insusceptible to all anthelmintics tested, except for selamectin at high drug concentrations. CLINICAL RELEVANCE: The in vitro anthelmintic response to antiparasitic agents may guide and improve disease therapy and prevention. Considering the observed lack of efficacy against L3, monthly anthelmintic treatment for protection against An vasorum infection in dogs would primarily rely on the anthelmintic's adulticidal activity. Maximal preventive control for An vasorum would, therefore, require at least 1 treatment administered a minimum of 1 week after the end of the transmission season.

Is the Angiostrongylus vasorum infection in domestic dogs underestimated or misdiagnosed? A comprehensive presentation of four lethal cases.

Introduction: Angiostrongylus vasorum (A. vasorum) is a widely distributed gastropod-borne nematode, causing severe cardio-pulmonary disorders in dogs. In Romania, A. vasorum was detected in foxes and serologically confirmed in domestic dogs, but no clinical cases are currently diagnosed. Methods: Four dogs with clinical history of respiratory distress, originating from different geographical regions of Romania, were included in the study. One dog (case 1) was clinically evaluated using thoracic radiology and cardiac ultrasound; examination of feces and PCR were also performed for the etiologic diagnosis. The postmortem exam was performed in the other three cases, followed by parasitological and molecular analyses. Results: In the first case, parasitic pneumonia was suspected based on the radiographic examination of the thorax and the infection with A. vasorum was confirmed by L1 morphological identification and PCR. The main postmortem changes included large, coalescing, dark red areas of pulmonary consolidation (n = 3) and numerous adult nematodes in the pulmonary arteries (n = 2). The histopathological examination of the lungs showed necrotizing and granulomatous pneumonia with severe hemorrhages and chronic pulmonary arterial changes. Intralesional nematodes were seen in all necropsied cases. Additional inflammatory changes related to A. vasorum infection were identified in the brain and tracheobronchial and mediastinal lymph nodes (n = 2). Identification of larvae, histopathology and PCR confirmed the infection with A. vasorum. Conclusions: This study describes the first cases of canine cardiopulmonary angiostrongylosis in domestic dogs in Romania, and focuses on clinical presentation, pathological findings and molecular analysis. Angiostrongylosis should be included on the list of differential diagnoses of canine cardiopulmonary distress and/or haemorrhagic diathesis in Romania and awareness should be raised among clinicians to avoid post-mortem diagnosis in the future.

Case report: Intracranial and spinal subarachnoid hemorrhage in a dog with Angiostrongylosis.

A 1-year-old male intact Staffordshire terrier, born and raised in the Netherlands, was presented with a 3-week history of progressive lethargy and spinal, predominantly cervical, hyperesthesia. Other than hyperthermia and cervical hyperesthesia, general and neurological examination did not reveal any abnormalities. Comprehensive hematological and biochemical tests were considered normal. Magnetic resonance imaging of the craniocervical region revealed heterogeneity of the subarachnoid space, characterized by pre-contrast T1W hyperintensity, corresponding to a T2* signal void. Extending from the caudal cranial fossa to the level of the third thoracic vertebra, there were uneven patchy extra-parenchymal lesions that caused mild spinal cord compression, most marked at the level of C2. At this level, the spinal cord showed an ill-defined hyperintense T2W intramedullary lesion. Mild intracranial and spinal meningeal contrast enhancement was evident on post-contrast T1W images. Subarachnoid hemorrhage was suspected, and further diagnostic tests including Baermann coprology resulted in a diagnosis of hemorrhagic diathesis caused by an Angiostrongylus vasorum infection. The dog rapidly responded to treatment with corticosteroids, analgesic medication, and antiparasitic treatment. Follow-up over 6 months yielded complete clinical remission and repeatedly negative Baermann tests. This case report details clinical and magnetic resonance imaging findings in a dog with subarachnoid hemorrhage associated with an Angiostrongylus vasorum infection.

Non-traumatic hemorrhagic myelopathy in dogs.

BACKGROUND: Non-traumatic spinal cord hemorrhage (NTSH) is an uncommon cause of myelopathy in dogs. OBJECTIVES: Describe the clinical characteristics, concurrent medical conditions and underlying causes, magnetic resonance imaging (MRI) findings and outcome in dogs with NTSH. ANIMALS: Dogs diagnosed with NTSH using gradient echo T2-weighted (GRE) sequences with or without histopathological confirmation of hemorrhage were included. Dogs with a traumatic cause were excluded, including those with compressive intervertebral disc extrusion. METHODS: Retrospective descriptive study; the databases of 2 referral hospitals were searched between 2013 and 2021. RESULTS: Twenty-three dogs met inclusion criteria. The onset of signs was acute and progressive in 70% of cases; spinal hyperesthesia was variable (48%). Hemorrhage was identified in the thoracolumbar spinal segments in 65% of dogs. An underlying cause was identified in 65% of cases. Angiostrongylus vasorum represented 18% of the total cohort, followed by steroid-responsive meningitis arteritis (SRMA; 13%). Overall, 64% of dogs had a good or excellent outcome, regardless of cause; which was increased to 100% for SRMA, 75% for A. vasorum and 75% for idiopathic NTSH. Outcome was not associated with neurological severity. Recovery rate was 67% and 50% for nociception-intact and nociception-negative dogs, respectively. CONCLUSIONS: Larger prospective studies would be required to define prognostic factors for dogs with NTSH, but outcome appeared to be most influenced by the underlying cause, as opposed to neurological severity at presentation.

Range of metastrongylids (superfamily Metastrongyloidea) of public health and veterinary concern present in livers of the endemic lizard Gallotia galloti of Tenerife, Canary Islands, Spain.

BACKGROUND: Endemic lizards of the genus Gallotia are of high ecological value to the terrestrial ecosystem of the archipelago of the Canary Islands, being potent seed spreaders as well as an important component of the diet of other vertebrates. The endemic lizard Gallotia galloti in Tenerife has recently been reported to be a paratenic host of Angiostrongylus cantonensis, an invasive metastrongylid with zoonotic potential that is associated with rats as definitive hosts. However, microscopic examination of G. galloti tissue samples also revealed the presence of other metastrongylid larvae inside granulomas on the liver of this reptile. The aim of this study was to investigate the presence of helminths other than A. cantonensis in tissues of G. galloti from Tenerife. METHODS: A multiplex-nested PCR targeting the internal transcribed spacer 1 was designed that enabled the species-specific detection of A. cantonensis, Angiostrongylus vasorum, Aelurostrongylus abstrusus, Crenosoma striatum and Crenosoma vulpis. Liver samples from 39 G. galloti were analysed. RESULTS: Five metastrongylids were detected: A. cantonensis (15.4% of samples analysed), A. vasorum (5.1%), Ae. abstrusus (30.8%), C. striatum (30.8%) and undetermined metastrongylid sequences (12.8%). Co-infection was highly prevalent among the lizards which tested positive. CONCLUSIONS: The study provides a new specific tool for the simultaneous detection of a range of metastrongylids of veterinary importance as well as new data on the circulation of metastrongylids in an ecosystem dominated by lizards.

Adult parasite burden and excretion of first-stage larvae of Angiostrongylus vasorum in dogs: Methodologically relevant diagnostic aspects and associations with serological detection of parasite antigen and specific antibodies.

Angiostrongylus vasorum is a widely distributed cardiopulmonary parasite of canids in Europe. Clinical signs in dogs can be highly variable and diagnostically challenging. A correct and early diagnosis is hence indispensable to adequately manage affected patients. First-stage larvae (L1) are excreted in the faeces of definitive hosts and conventionally identified using the Baermann technique. Moreover, ELISAs for the detection of circulating antigen and specific antibodies have been presented. The current study aimed at i) quantitatively assessing larval migration in the Baermann funnel after 12 h and 24 h; ii) investigating the influence of sample storage at 4 °C over the course of three days on the number of detected L1; iii) evaluating potential associations of adult worm burdens with larval shedding in dogs and ELISA optical density (OD) values for circulating parasite antigen and specific antibodies. Faecal samples were obtained from naturally infected dogs (n = 21) and Baermann funnels were set up in duplicate over the course of four consecutive days (days 0-3) starting with the day of sample collection. Funnels were harvested on days 1-4 after 12 and 24 h, respectively, and the number of L1 per gram faeces (LPG) was determined. The LPG did not differ between larval harvest after 12 h from harvest after 24 h. Storage of faecal samples at 4 °C for two and three days entailed a considerable decrease in LPG. Adult worm burdens and larval excretion data from previous experiments demonstrated a correlation between worm burden and LPG. In contrast, no correlations between worm burden and the level of parasite antigen and specific antibody OD values, respectively, were identified. Thus, OD values of both antigen and antibody ELISA did not allow for conclusions on infection intensity reflected by the number of adult parasites. For the detection of L1 in faeces, 12 or 24 h of larval migration time was not discriminating for A. vasorum positivity. Thus, early processing of faecal samples is essential, since larval detection and hence sensitivity of the approach considerably decreased over the course of three days of storage. Therefore, the common recommendation to collect faecal samples for three consecutive days and to subsequently analyse them needs to be reconsidered. The results of this study can be readily translated into precise recommendations for daily practice to adequately assess A. vasorum infected dogs.

Systemic Infection by Angiostrongylus vasorum in a Fennec (Vulpeszerda) in an Italian Zoological Garden.

This paper reported a case of a metastrongyloid nematode Angiostrongylus vasorum infection in a fennec (Vulpes zerda) kept in a zoo in central Italy. The fennec had shown paralysis of the hind limbs, anorexia, weakness and respiratory signs before death. Cardiomegaly and granulomatous pneumonia were the major anatomopathological findings. Inflammatory lesions associated with parasitic larvae were observed in the lungs, brain, liver, heart, spinal cord and kidney of the fennec at histology. A. vasorum diagnosis was confirmed by both morphological and molecular identification of adult worms recovered at necropsy. Fennecs are active predators and maintain their hunting behaviour in captivity. Hence, it is likely that the animal was exposed to infection by preying on parasitised gastropods, intermediate hosts of A. vasorum, entering zoo enclosures from the surrounding environment. This is the first report of A. vasorum systemic infection in a captive fennec (V. zerda) in a zoo in Italy.

Comprehensive Map of Canine Angiostrongylosis in Dogs in Spain.

Canine angiostrongylosis is an emerging disease caused by Angiostrongylus vasorum, mainly affecting wild carnivores and dogs. In Spain, there are studies reporting infections in foxes, wolves, and badgers in different regions of the country. However, there are hardly any publications on its prevalence in dogs. The aim of this study was to complete and update the epidemiologic map of A. vasorum in dogs in Spain. A total of 5619 canine blood samples from all autonomous cities and provinces of Spain were collected and tested for the presence of circulating A. vasorum antigens. The overall apparent prevalence of canine A. vasorum infection in Spain was 1.39%. No significant differences were found for sex or age, but significant differences between outdoor and indoor/outdoor dogs were found. A high prevalence was also observed in the northern third of the country, where an oceanic climate prevails, being humid and rainy and where abundant vegetation can be found, thus favoring the proliferation of intermediate hosts. The results suggest that A. vasorum canine infections are heterogeneously present in a large part of the territory, demonstrating its expansion throughout the country, and therefore, awareness and prevention campaigns for this disease should be promoted.

A High Prevalence of Cardiopulmonary Worms Detected in the Iberian Wolf (Canis lupus): A Threat for Wild and Domestic Canids.

Cardiopulmonary nematodes are highly pathogenic parasites affecting domestic and wild canids. As the result of conservation programs, the Iberian wolf (Canis lupus signatus) population has recently expanded, and its distribution range covers lands from where it had long disappeared. However, the exact epidemiological role of the wolf in the life cycle of zoonotic parasites causing diseases transmissible to pets and/or humans is largely unknown. This study sought to determine the diversity of cardiopulmonary nematode parasite species that affect wolves inhabiting northwestern areas of the Iberian Peninsula, and to estimate their prevalence and the relationship between these parasites and several epidemiological variables. For this purpose, we examined the cardiopulmonary systems of 57 wolves from Galicia (from the provinces A Coruña n = 15, Lugo n = 21, Ourense n =15 and Pontevedra n = 6) using techniques of dissection and cup sedimentation. Collected worms were then identified under a light microscope according to their morphological features. Three species of nematodes were detected: Angiostrongylus vasorum (the "French-heartworm"), Crenosoma vulpis and Eucoleus aerophilus, the latter being of zoonotic interest. The prevalence was 24.5% (14/57; 95% CI 13.3-35.6%) overall, 19.3% for A. vasorum (11/57; 95% CI 8.8-29.2%), 7% for C. vulpis (4/57; 95% CI 0.4-13.6%) and 3.5% for E. aerophilus (2/57; CI -1.1-9.1%). A significant relationship (p = 0.002) was found between age and the presence of C. vulpis, which was only found in juvenile animals. Furthermore, a higher prevalence of A. vasorum and/or C. vulpis was observed in wolves with a lower body condition score (40% and 20%, respectively), though the difference was not significant (p = 0.221 and p = 0.444, respectively). Our findings indicate a high "French-heartworm" and lungworm burden in the wolf population of northern Spain, and they identify a need for studies designed to elucidate the epidemiological role played by the Iberian wolf and to identify possible risks for veterinary and public health.

Nationwide Seroprevalence Survey of Angiostrongylus vasorum-Derived Antigens and Specific Antibodies in Dogs from Colombia.

Angiostrongylus vasorum is a cardiopulmonary nematode, causing several clinical manifestations in dogs, e.g., severe respiratory signs, coagulopathy, and gastrointestinal or neurological signs. In the last decades, this parasite has been described to spread and emerge in Europe and North America. Scant studies on A. vasorum occurrence in South America exist. Recently, A. vasorum was detected in gastropod intermediate hosts in Colombia, where data on definitive host prevalence, e.g., dogs and wild canids, are still limited. Therefore, the sera of 955 dogs, varying in age and breed from seven different departments all over Colombia, were collected and analysed for A. vasorum antigens and parasite-specific antibodies by ELISA. In total, 1.05 % (n = 10; 95 % CI 0.40-1.69) of the samples were antigen-positive and 2.62 % (n = 25; 95 % CI 1.61-3.63) were antibody-positive. These results confirm the presence of A. vasorum in Colombia, although positive results in antigen and antibody reactions in the same dog were not detected. This study is the first large-scale survey on A. vasorum seroprevalences in dogs from Colombia.

Angiostrongylus vasorum, Aelurostrongylus abstrusus, Crenosoma vulpis and Troglostrongylus brevior Infections in Native Slug Populations of Bavaria and Baden-Wuerttemberg in Germany.

Angiostrongylus vasorum, Crenosoma vulpis, Aelurostrongylus abstrusus and Troglostrongylus brevior can cause severe cardiovascular and pulmonary symptoms in companion animals and wildlife. Recently, these nematodes were reported to spread within Europe and South America. The reasons behind this are still unknown, but obligate gastropod intermediate host populations might play a role. Therefore, lungworm infections in terrestrial slug populations in selected geographic areas of the Federal States of Bavaria and of Baden-Wuerttemberg, Germany, were studied. In total, 517 slugs (462 Arion spp., 51 Deroceras reticulatum, one Limax maximus, and three unknown slug species) were collected in the summer and autumn seasons, artificially digested and microscopically and molecularly analyzed for the presence of metastrongyloid lungworm larvae. Overall, gastropods showed a prevalence of 11.61% (60/517) for A. vasorum, 1.74% (9/517) for A. abstrusus, 0.77% (4/517) for C. vulpis and 0.97% (5/517) for T. brevior infections, respectively. In Obrigheim (Baden-Wuerttemberg), a hyperendemic focus of canine angiostrongylosis was identified. Here, gastropod infection rates rose from 13.60% (17/125) to 62.96% (34/54) within a few months. In total, 25.61% (84/328) of analysed terrestrial gastropods from Baden-Wuerttemberg were positive for metastrongyloids. In contrast, Bavarian gastropods showed a much lower prevalence of 4.76% (9/189). For the first time, the presence of T. brevior was confirmed for Arion spp. in Baden-Wuerttemberg via molecular analyses. Overall, the current data confirm that canine angiostrongylosis occurs in hyperendemic foci in certain geographic areas with high infection rates in intermediate host populations. As a result, the prevalence for a specific region can rise remarkably within a short period of time. Thus, for a better understanding of lungworm epidemiology in Germany and to protect dogs from angiostrongylosis in hyperendemic foci, it seems mandatory to enhance current efforts on Metastrongyloidea-targeted monitoring on a geographical and time span-related level.

Microbiome dataset of the cardiopulmonary nematode Angiostrongylus vasorum.

Angiostrongylus vasorum is an emerging parasitic nematode of dogs, red foxes, and other wild canids. The severity of infection in dogs ranges from subclinical to fatal cardiopulmonary and bleeding disorders collectively known as canine angiostrongylosis. A symbiotic relationship between microorganisms such as bacteria and their eukaryotic hosts is commonly observed in nature. The mutualistic role of bacteria has been documented in plant-parasitic nematodes, gastrointestinal nematodes, and filarial nematodes. The importance of the bacteria for the survival of these parasites has been demonstrated with antibiotic treatments. To characterize associated bacteria of adult A. vasorum parasites, 36 individual worm samples were used. The worms were extracted from foxes hunted either in the city or in the rural regions within the Canton of Zurich, Switzerland. DNA was isolated and the V3/V4 hypervariable region of the bacterial 16S rRNA gene was amplified. Sequenced Illumina MiSeq reads were analysed using QIIME2. The data were used to profile the abundance and diversity of microbial communities in worms originating from either rural or urban foxes.

Serological and faecal detection of Angiostrongylus vasorum in dogs from Austria.

Canine angiostrongylosis is a potentially lethal parasitic disease that can manifest itself with a broad spectrum of clinical signs, including respiratory distress, neurological and bleeding disorders, or non-specific signs. The occurrence of Angiostrongylus vasorum is widely reported in Europe, but very little is known about its presence in Austria. In this first large-scale survey, 1279 sera were collected from Austrian dogs and tested by an ELISA for the detection of circulating antigen of A. vasorum (sensitivity: 95.7%, specificity 94.0%) and by a separate ELISA detecting specific antibodies (sensitivity 81.0%, specificity 98.8%). Furthermore, 1040 faecal samples were tested for the presence of lungworm first stage larvae (L1). One dog (0.1%, 95% confidence intervals [CI]: 0.0-0.4%) was positive in both ELISAs, while 1.2% (n = 15, CI: 0.7-1.9%) of the tested dogs were antigen-positive and 1.5% (n = 19, CI: 0.9-2.3%) were positive for specific antibodies. Overall, 13 dogs (1.3%; CI: 0.7-2.1%) were positive for A. vasorum L1 while 31 dogs were positive for Crenosoma vulpis L1 (3.0%; CI: 2.0-4.2%). One dog shed L1 from both A. vasorum and C. vulpis (0.1%, CI: 0.0-0.5%). Dogs positive for A. vasorum originated from northeast, southeast and south Austria (antigen and/or antibody detection), but also from north, west and southwest Austria (antibody detection) and from northeast and west Austria (L1 detection). One of 88 blood samples (1.1%, CI: 0.0-6.2%) submitted from the eastern part of Austria was positive by a rapid assay for A. vasorum antigen detection (Angio Detect™). Crenosoma vulpis positive samples originated from northwest, north, northeast, south and west Austria. These results confirm the very sporadic occurrence of A. vasorum in the investigated areas of the country. However, due to the substantial infectious pressure from the surrounding countries and the free circulation of dogs and foxes acting as wildlife reservoirs and due to clinical relevance for infected dogs, it is crucial to maintain disease awareness also in areas where the parasite has not yet been detected.

Pneumothorax in a persistent canine Angiostrongylus vasorum infection.

Canine angiostrongylosis is a gastropod-borne parasitosis caused by the cosmopolitan nematode Angiostrongylus vasorum. It is associated with cardiorespiratory disorders and eventually fatal coagulopathies. A 6-months-old female dog previously diagnosed with bronchopneumonia and pneumothorax, treated accordingly without success, was hospitalized for further treatment. Complementary diagnostics confirmed previous findings plus pneumomediastinum, thoracic exudate, leucocytosis, thrombocytosis, hypercoagulability, and hyperglobulinemia. Coprological analysis showed a severe patent A. vasorum infection. After the third daily fenbendazole administration, all A. vasorum larvae were found dead in follow-up coprological analyses while in intensive care. Upon release, the dog was monitored until full clinical recovery 3 months later. Up to date, A. vasorum infection-related pneumothorax was rarely described, particularly with full recovery of such a young patient. Thus, a parasitological aetiology should be considered for dogs with severe bronchopneumonia or pneumothorax, especially in Europe and South America where increasing numbers of canine angiostrongylosis cases call for enhanced awareness of veterinary practitioners.

Highly Variable Clinical Pictures in Dogs Naturally Infected with Angiostrongylus vasorum.

Canine angiostrongylosis by Angiostrongylus vasorum is increasingly reported in both enzootic and previously free areas. The complex pathogenesis of the disease makes the clinical workup challenging. Infected dogs show highly variable clinical pictures, characterized by subclinical to life-threatening general, cardio-respiratory, neurological and/or gastrointestinal signs. The present study reports the high variability of clinical pictures from 36 dogs across central and southern Italy that were naturally infected by A. vasorum. Of them, 23 (63.9%) presented at least one clinical sign, while 13 (36.1%) were subclinically infected and apparently healthy. Overall, 19 dogs (52.8%) showed cardiorespiratory signs, 14 (38.9%) had non-specific abnormalities, 2 (5.6%) presented coagulation disorders and 1 (2.8%) had a severe neurological condition. Importantly, four dogs presenting with clinical signs had neither cough nor dyspnea. These results underline that angiostrongylosis should be included in the differential diagnosis, even when dogs display only non-specific clinical signs. The proportion of apparently healthy dogs highlights the relevance of routine copromicroscopic and/or antigenic tests in enzootic areas to avoid the sudden onset of potentially life-threatening signs.

Fox Serum Proteomics Analysis Suggests Host-Specific Responses to Angiostrongylus vasorum Infection in Canids.

Dogs infected with the cardiopulmonary nematode Angiostrongylus vasorum may suffer from respiratory distress and/or bleeding disorders. Descriptions of clinical signs in foxes are rare, despite high prevalence. To evaluate the impact of infection on coagulation and immune response, serum proteins from eight experimentally infected foxes before and after inoculation (day 0, 35, 84, 154) were subjected to differential proteomic analyses based on quantitative data and compared to available data from dogs. The number of proteins with differential abundance compared to the uninfected baseline increased with chronicity of infection. Bone marrow proteoglycan, chitinase 3-like protein 1 and pulmonary surfactant-associated protein B were among the most prominently increased proteins. The abundance of several proteins involved in coagulation was decreased. Enriched pathways obtained from both increased and decreased proteins included, among others, "platelet degranulation" and "haemostasis", and indicated both activation and suppression of coagulation. Qualitative comparison to dog data suggests some parallel serum proteomic alterations. The comparison, however, also indicates that foxes have a more adequate immunopathological response to A. vasorum infection compared to dogs, facilitating persistent infections in foxes. Our findings imply that foxes may be more tolerant to A. vasorum infection, as compared to dogs, reflecting a longer evolutionary host-parasite adaptation in foxes, which constitute a key wildlife reservoir.

The Angiostrongylus vasorum Excretory/Secretory and Surface Proteome Contains Putative Modulators of the Host Coagulation.

Angiostrongylus vasorum is a cardiopulmonary nematode of canids and is, among others, associated with bleeding disorders in dogs. The pathogenesis of such coagulopathies remains unclear. A deep proteomic characterization of sex specific A. vasorum excretory/secretory proteins (ESP) and of cuticular surface proteins was performed, and the effect of ESP on host coagulation and fibrinolysis was evaluated in vitro. Proteins were quantified by liquid chromatography coupled to mass spectrometry and functionally characterized through gene ontology and pathway enrichment analysis. In total, 1069 ESP (944 from female and 959 from male specimens) and 1195 surface proteins (705 and 1135, respectively) were identified. Among these were putative modulators of host coagulation, e.g., von Willebrand factor type D domain protein orthologues as well as several proteases, including serine type proteases, protease inhibitors and proteasome subunits. The effect of ESP on dog coagulation and fibrinolysis was evaluated on canine endothelial cells and by rotational thromboelastometry (ROTEM). After stimulation with ESP, tissue factor and serpin E1 transcript expression increased. ROTEM revealed minimal interaction of ESP with dog blood and ESP did not influence the onset of fibrinolysis, leading to the conclusion that Angiostrongylus vasorum ESP and surface proteins are not solely responsible for bleeding in dogs and that the interaction with the host's vascular hemostasis is limited. It is likely that coagulopathies in A. vasorum infected dogs are the result of a multifactorial response of the host to this parasitic infection.

Dirofilaria spp. and Angiostrongylus vasorum: Current Risk of Spreading in Central and Northern Europe.

In the past few decades, the relevance of Dirofilaria immitis and Dirofilaria repens, causing cardiopulmonary and subcutaneous dirofilariosis in dogs and cats, and of Angiostrongylus vasorum, causing canine angiostrongylosis, has steadily increased in Central and Northern Europe. In this review, a summary of published articles and additional reports dealing with imported or autochthonous cases of these parasites is provided for Central (Austria, Czechia, Germany, Hungary, Luxemburg, Poland, Slovakia, Slovenia, and Switzerland) and Northern (Denmark, Finland, Iceland, Norway, and Sweden) Europe. Research efforts focusing on Dirofilaria spp. and A. vasorum have varied by country, and cross-border studies are few. The housing conditions of dogs, pet movements, the spread of competent vectors, and climate change are important factors in the spread of these nematodes. Dogs kept outside overnight are a major factor for the establishment of Dirofilaria spp. However, the establishment of invasive, diurnal, synanthropic, competent mosquito vectors such as Aedes albopictus may also influence the establishment of Dirofilaria spp. The drivers of the spread of A. vasorum remain not fully understood, but it seems to be influenced by habitats shared with wild canids, dog relocation, and possibly climatic changes; its pattern of spreading appears to be similar in different countries. Both Dirofilaria spp. and A. vasorum merit further monitoring and research focus in Europe.