Infectivity of gastropod-shed third-stage larvae of Angiostrongylus vasorum and Crenosoma vulpis to dogs.

BACKGROUND: Metastrongyloid parasites Angiostrongylus vasorum and Crenosoma vulpis infect wild and domestic canids and are important pathogens in dogs. Recent studies indicate that gastropod intermediate hosts infected with various metastrongyloids spontaneously shed infective third-stage larvae (L3) into the environment via feces and mucus under laboratory conditions. Shed L3 retain motility up to 120 days, but whether they retain infectivity was unknown. METHODS: To assess the infectivity of shed L3, the heart/lungs of six red foxes (Vulpes vulpes) were obtained from trappers in Newfoundland, Canada. Lungs were examined for first-stage larvae (L1) by the Baermann technique. A high number of viable A. vasorum L1 and a low number of C. vulpis L1 were recovered from one fox; these were used to infect naïve laboratory-raised Limax maximus. L3 recovered from slugs by artificial digestion were fed to two naïve purpose-bred research beagles (100 L3/dog). L1 shed by these two dogs was used to infect 546 L. maximus (2000-10,000 L1/slug). L3 shedding was induced by anesthetizing slugs in soda water and transferring them into warm (45 °C) tap water for at least 8 h. Shed L3 recovered from slugs were aliquoted on romaine lettuce in six-well tissue culture plates (80-500 L3/well) and stored at 16 °C/75% relative humidity. Four naïve research beagles were then exposed to 100 L3/dog from larvae stored for 0, 2, 4, or 8 weeks, respectively, after shedding. RESULTS: All four dogs began shedding C. vulpis L1 by 26-36 days post-infection (PI). All four dogs began shedding A. vasorum L1 by 50 days PI. CONCLUSIONS: L3 infectivity for the definitive host was retained in both metastrongyloids, indicating the potential for natural infection in dogs through exposure from environmental contamination. As an additional exposure route, eating or licking plant or other material(s) contaminated with metastrongyloid L3 could dramatically increase the number of dogs at risk of infection from these parasites.

Determinants of lungworm specificity in five cetacean species in the western Mediterranean.

BACKGROUND: Current data about Pseudaliidae show contrasting patterns of host specificity between congeneric species. We investigated how both contact and compatibility between hosts and parasites contributed to the patterns of lungworm infection observed in a community of five species of cetaceans in the western Mediterranean. METHODS: The lungs of 119 striped dolphins Stenella coeruleoalba, 18 bottlenose dolphins Tursiops truncatus, 7 Risso's dolphins Grampus griseus, 7 long-finned pilot whales Globicephala melas, and 6 common dolphins Delphinus delphis were analysed for lungworms. Parasites were identified by morphology and analysis of ITS2 sequences using both maximum likelihood and Bayesian inference methods. Body length was used as a proxy for lungworm species fitness in different hosts and compared with Kruskal-Wallis tests. Infection parameters were compared between cetacean species using Fisher's exact tests and Kruskal-Wallis tests. Phylogenetic specificity was explored by collating the overall lungworm species prevalence values in hosts from previous surveys in various localities. To explore the relative importance of vertical and horizontal transmission, Spearman's rank correlation was used to look for an association between host size and lungworm burden. A Mantel test was used to explore the association between lungworm species similarity and prey overlap using dietary data. RESULTS: Halocercus delphini had higher infection levels in striped dolphins and common dolphins; Stenurus ovatus had higher infection levels in bottlenose dolphins; and Stenurus globicephalae had higher infection levels in long-finned pilot whales. These results are congruent with findings on a global scale. Morphometric comparison showed that the larger nematodes were found in the same host species that had the highest parasite burden. Lungworms were found in neonatal striped dolphins and a Risso's dolphin, and there was a weak but significant correlation between host size and parasite burden in striped dolphins and bottlenose dolphins. There was also a weak but significant association between prey overlap and lungworm species similarity. CONCLUSIONS: Data indicate that phylogenetic specificity has an important role in governing host-parasite associations, as indicated by the higher infection levels and larger nematode size in certain hosts. However, diet can also influence infection patterns in these preferred hosts and contribute to less severe infections in other hosts.

Evaluation of terrestrial gastropods as possible intermediate hosts of Gurltia paralysans in southern Chile.

Gurltia paralysans is the causal agent of gurltiosis in domestic cats in South America. Although the life cycle of G. paralysans is unknown, it is thought that gastropods could act as intermediate hosts (IHs), as is the case for several nematodes in the Angiostrongylidae family. The aim of this study was to search for G. paralysans larvae in terrestrial gastropods and determine their role in the life cycle of this nematode species. Terrestrial gastropod samples (n=835) were collected in Punucapa, Valdivia, southern Chile, where cases of gurltiosis had been reported before. The samples included species from the families Arionidae, Limacidae, Helicidae and Milacidae. All gastropods were subjected to enzymatic digestion to isolate G. paralysans larvae. Ten percent of the gastropod samples were analyzed using seminested PCR targeting the 28S rRNA gene, while 2.6% were analyzed by histopathological examination. The results indicated the absence of G. paralysans when using any of the three methods. In conclusion, further studies are needed to evaluate specific species of aquatic or native gastropods acting as possible IHs (in this geographic location).

Evaluation of terrestrial gastropods as possible intermediate hosts of Gurltia paralysans in southern Chile / Avaliação de gastrópodes terrestres como possíveis hospedeiros intermediários de Gurltia paralysans no sul do Chile

Abstract Gurltia paralysans is the causal agent of gurltiosis in domestic cats in South America. Although the life cycle of G. paralysans is unknown, it is thought that gastropods could act as intermediate hosts (IHs), as is the case for several nematodes in the Angiostrongylidae family. The aim of this study was to search for G. paralysans larvae in terrestrial gastropods and determine their role in the life cycle of this nematode species. Terrestrial gastropod samples (n=835) were collected in Punucapa, Valdivia, southern Chile, where cases of gurltiosis had been reported before. The samples included species from the families Arionidae, Limacidae, Helicidae and Milacidae. All gastropods were subjected to enzymatic digestion to isolate G. paralysans larvae. Ten percent of the gastropod samples were analyzed using seminested PCR targeting the 28S rRNA gene, while 2.6% were analyzed by histopathological examination. The results indicated the absence of G. paralysans when using any of the three methods. In conclusion, further studies are needed to evaluate specific species of aquatic or native gastropods acting as possible IHs (in this geographic location).

Resumo Gurltia paralysans é o agente etiológico da gurltiose em gatos domésticos na América do Sul. Embora o ciclo biologico de G. paralysans seja desconhecido, provavelmente é indireto com gastrópodes atuando como hospedeiros intermediários (HIs), como no caso de vários nematoides da família Angiostrongylidae. O objetivo deste estudo foi investigar a presença de larvas de G. paralysans em gastrópodes terrestres para avaliar seu papel no ciclo de vida do parasito. Amostras de gastrópodes terrestres (n = 835) foram coletadas em Punucapa, Valdivia, sul do Chile, onde casos de gurltiose foram relatados anteriormente. As amostras incluíram espécies das famílias Arionidae, Limacidae, Helicidae e Milacidae. Todos os gastrópodes foram submetidos à digestão enzimática para isolar as larvas de G. paralysans. 10% das amostras foram analisadas, utilizando-se seminested PCR para o gen 28S RNAr de G. paralysans, enquanto 2,6% foram analisados ​​por exame histopatológico. Os resultados indicaram ausência de G. paralysans em todos os três métodos. Os dados permitem concluir que são necessários mais estudos para avaliar espécies específicas de gastrópodes aquáticos ou nativos, que atuam como possíveis hospedeiros intermediários nessa localização geográfica.

Additional characterization of the adult worm Mammomonogamus laryngeus (Railliet, 1899) and the tissue lesions caused by the infection in buffaloes.

Mammomonogamus spp. are parasites with curious characteristics, such as the "Y" shape that results from male and female maintaining the permanent copulation position and the controversial presence or absence of spicules. These nematodes are hematophagous and cause damage to the upper respiratory tracts of cattle, sheep, goats, deer, wild yaks, and orangutans. Human infection is rare and most cases until now have been in the Caribbean Islands or in Brazil, and mainly in farmworkers but recently there have been reports affecting tourists. In the present work, the parasites were recovered from the laryngopharynx and larynx region of Bubalus bubalis on the island of Marajó, Pará, Brazil. Different microscopy methodologies were applied (bright field, fluorescence, and scanning electron microscopy) to explore the ultrastructural details of the anterior end, genital structures and the host tissue damage caused by the nematodes. The well-developed mouth is an important structure in the identification of these nematodes and used by the parasite to adhere to the host's tissue. Different methodologies in microscopy and molecular biology contributed to a detailed morphological description and showed the phenotypic position of Mammomonogamus laryngeus. Light and scanning electron microscopy (SEM) showed details of the papillae, amphids, festoons, ribs, and teeth. Fluorescence microscopy enabled a detailed characterization of different structures, such as the bursal rays and SEM enabled the visualization of the specialized features of the cuticle surface in the male and female. Histopathological analyses, cryofracture and environmental SEM experiments of the infected tissues were carried out in order to investigate the lesions resultant from the parasitism. In addition, the parasite couples were submitted to cryofracture and these results revealed details of the reproductive structures of both sexes, including the male spicule.

Conquering Switzerland: the emergence of Angiostrongylus vasorum in foxes over three decades and its rapid regional increase in prevalence contrast with the stable occurrence of lungworms.

Angiostrongylus vasorum, Crenosoma vulpis and Capillaria aerophila are the most common lungworms of domestic and wild canids. We investigated the short- and long-term lungworm prevalence changes in the Swiss fox population with a focus on A. vasorum. Between 2012 and 2017, lungs and hearts of 533 foxes from north-eastern Switzerland were necropsied and blood samples tested for circulating A. vasorum antigen. Angiostrongylus vasorum prevalence increased steadily from 21.5% in 2012 to 81.8% in 2017. In contrast, C. aerophila and C. vulpis prevalences fluctuated between 41.8 and 74.7%, and 3.6 and 14.9%, respectively. Based on 3955 blood samples collected between 1986 and 2017 from three geographic areas and during four time periods, antigen seropositivity increased from 2.4 to 62.0%. In north-eastern Switzerland, seropositivity was initially low (1.9 and 1.7% in the first two time periods) but increased in the following two decades to 22.2 and 62.0%, respectively. Our findings depict the spectacular expansion of A. vasorum in the past three decades. Regionally, the prevalence in foxes increased 4-fold within 6 years in some regions. This underpins the important role of foxes as reservoir hosts, likely explaining the increasing number of cases of canine angiostrongylosis in Switzerland. Our findings are representative of central Europe and may help anticipating future developments in areas where A. vasorum is present but (still) infrequent.

Infection with brainworm (Elaphostrongylus rangiferi) in reindeer (Rangifer tarandus ssp.) in Fennoscandia.

Sami reindeer herders have considerable traditional knowledge about a neurological reindeer disease resembling elaphostrongylosis, but the causative agent was not identified prior to the description of the brainworm Elaphostrongylus rangiferi in Russia in 1958. Elaphostrongylosis was quickly recognised as a serious cause of reindeer morbidity and mortality. The ecology, epidemiology and pathophysiology of the disease were studied in Sweden and Norway during the 1960s and in particular the 1970s to 1990s. In Finland, elaphostrongylosis was not recognised as an important disease for Finnish reindeer husbandry, even though the presence of brainworm infection has been documented. Brainworm has an indirect lifecycle with snail and slug intermediate hosts. The free-living L1 larvae have extremely good freeze tolerance and can survive > 360 days at - 80 °C in water (solid ice). Even though reindeer brainworm is clearly well adapted to the Arctic chill, the lifecycle stages outside the reindeer final host are sped up at warmer environmental temperatures. Arctic summer temperatures are close to the developmental threshold of the parasite in the intermediate gastropod hosts (8-10 °C), and the parasite has typically had a 2-year life cycle. Disease outbreaks generally occur during the winter following the infection of reindeer with infected snails and slugs during the summer and autumn. Warmer summers result in faster development of brainworm larvae in the intermediate hosts. Clinical symptoms have been seen reported as early as August, such as in the outbreak in Trøndelag, Norway in 2018. The reindeer brainworm is also a cause of conflict between reindeer herders and small ruminant farmers, because it can cause severe disease in goats and sheep, which share pasture with reindeer. Many knowledge gaps remain if we wish to successfully predict and mitigate for large-scale outbreaks in a future with a predicted warmer, wetter and wilder climate.

The Fine-Scale Landscape of Immunity and Parasitism in a Wild Ungulate Population.

Spatial heterogeneity in susceptibility and exposure to parasites is a common source of confounding variation in disease ecology studies. However, it is not known whether spatial autocorrelation acts on immunity at small scales, within wild animal populations, and whether this predicts spatial patterns in infection. Here we used a well-mixed wild population of individually recognized red deer (Cervus elaphus) inhabiting a heterogeneous landscape to investigate fine-scale spatial patterns of immunity and parasitism. We noninvasively collected 842 fecal samples from 141 females with known ranging behavior over 2 years. We quantified total and helminth-specific mucosal antibodies and counted propagules of three gastrointestinal helminth taxa. These data were analyzed with linear mixed models using the Integrated Nested Laplace Approximation, using a Stochastic Partial Differentiation Equation approach to control for and quantify spatial autocorrelation. We also investigated whether spatial patterns of immunity and parasitism changed seasonally. We discovered substantial spatial heterogeneity in general and helminth-specific antibody levels and parasitism with two helminth taxa, all of which exhibited contrasting seasonal variation in their spatial patterns. Notably, Fasciola hepatica intensity appeared to be strongly influenced by the presence of wet grazing areas, and antibody hotspots did not correlate with distributions of any parasites. Our results suggest that spatial heterogeneity may be an important factor affecting immunity and parasitism in a wide range of study systems. We discuss these findings with regards to the design of sampling regimes and public health interventions, and suggest that disease ecology studies investigate spatial heterogeneity more regularly to enhance their results, even when examining small geographic areas.

Shedding of feline lungworm larvae and their infectivity to snail intermediate hosts after anthelmintic treatment.

Aelurostrongylus abstrusus and Troglostrongylus brevior are snail-transmitted helminths causing respiratory diseases in infected cats. The shedding of feline lungworm L1s and their infectivity to the snail intermediate host, after administration of anthelminthic products to cats, are poorly documented. To assess the efficacy of 8.3% fipronil, 10% (S)-methoprene, 0.4% eprinomectin and 8.3% praziquantel (i.e. eprinomectin formulation) and 10% imidacloprid/1% moxidectin (i.e. moxidectin formulation) against these nematodes and to determine the number of days post-treatment until viable L1s are released in the faeces, 384 animals were screened by faecal examination. Of the 54 positive animals (i.e., 14.1%; 7.3% A. abstrusus, 6.2% T. brevior and 0.5% coinfected), 36 were randomly allocated to four groups. Groups A and B were composed of cats positive for T. brevior and treated with the eprinomectin and with the moxidectin formulations, respectively, whereas cats in groups C and D were positive to A. abstrusus and treated with the eprinomectin and the moxidectin formulations, respectively. Prior to and every day after treatment, faecal samples were analysed by the Baermann technique and the number of larvae per gram of faeces determined, and again four weeks after treatment, to assess the efficacy of a single administration of the products. In addition, to evaluate the pre- and post-treatment infectivity of L1s to snail intermediate hosts, one/two snails per cat were infected with 100 L1s collected from the faeces of enrolled animals and then digested 28 days p.i. Based on L1s faecal counts, the efficacy of the eprinomectin and the moxidectin formulations at 28 days was 100% for both A. abstrusus and T. brevior, with a mean number of days of 7.9 ±â€¯1.2 in group A, 7.8 ±â€¯1.9 in B, 6.9 ±â€¯1.6 in C and 8.9 ±â€¯2.0 in D to become negative. Following the artificial digestion, active L3s of T. brevior and A. abstrusus were found in 160 (87.4%) experimentally infected snails. The results of this study demonstrate that a single administration of the two formulations is effective in the treatment of A. abstrusus and T. brevior infections and that during the post-treatment period live L1s are shed for up to 8.9 ±â€¯2.0 days. L1s of both lungworm species released in the faeces after drug administration are still able to reach the infective larval stage in the infected snails. Hence, preventative measures after the treatment of infected animals should include keeping cats indoors and disposal of their faeces for approximately 10 days to avoid environmental contamination and infection of gastropod intermediate hosts.

Temperature-dependent development and freezing survival of protostrongylid nematodes of Arctic ungulates: implications for transmission.

BACKGROUND: Umingmakstrongylus pallikuukensis and Varestrongylus eleguneniensis are two potentially pathogenic lungworms of caribou and muskoxen in the Canadian Arctic. These parasites are currently undergoing northward range expansion at differential rates. It is hypothesized that their invasion and spread to the Canadian Arctic Archipelago are in part driven by climate warming. However, very little is known regarding their physiological ecology, limiting our ability to parameterize ecological models to test these hypotheses and make meaningful predictions. In this study, the developmental parameters of V. eleguneniensis inside a gastropod intermediate host were determined and freezing survival of U. pallikuukensis and V. eleguneniensis were compared. METHODS: Slug intermediate hosts, Deroceras laeve, were collected from their natural habitat and experimentally infected with first-stage larvae (L1) of V. eleguneniensis. Development of L1 to third-stage larvae (L3) in D. laeve was studied at constant temperature treatments from 8.5 to 24 °C. To determine freezing survival, freshly collected L1 of both parasite species were held in water at subzero temperatures from -10 to -80 °C, and the number of L1 surviving were counted at 2, 7, 30, 90 and 180 days. RESULTS: The lower threshold temperature (T0) below which the larvae of V. eleguneniensis did not develop into L3 was 9.54 °C and the degree-days required for development (DD) was 171.25. Both U. pallikuukensis and V. eleguneniensis showed remarkable freeze tolerance: more than 80% of L1 survived across all temperatures and durations. Larval survival decreased with freezing duration but did not differ between the two species. CONCLUSION: Both U. pallikuukensis and V. eleguneniensis have high freezing survival that allows them to survive severe Arctic winters. The higher T0 and DD of V. eleguneniensis compared to U. pallikuukensis may contribute to the comparatively slower range expansion of the former. Our study advances knowledge of Arctic parasitology and provides ecological and physiological data that can be useful for parameterizing ecological models.

Current knowledge about Aelurostrongylus abstrusus biology and diagnostic

Feline aelurostrongylosis, caused by the lungworm Aelurostrongylus abstrusus, is a parasitic disease with veterinary importance. The female hatches her eggs in the bronchioles and alveolar ducts, where the larva develop into adult worms. L1 larvae and adult nematodes cause pathological changes, typically inflammatory cell infiltrates in the bronchi and the lung parenchyma. The level of infection can range from asymptomatic to the presence of severe symptoms and may be fatal for cats. Although coprological and molecular diagnostic methods are useful for A. abstrusus detection, both techniques can give false negative results due to the presence of low concentrations of larvae in faeces and the use of inadequate diagnostic procedures. The present study describes the biology of A. abstrusus, particularly the factors influencing its infection and spread in intermediate and paratenic hosts, and the parasitic interactions between A. abstrusus and other pathogens.

Larval development of Aelurostrongylus abstrusus in experimentally infected Rumina decollata snails.

Aelurostrongylus abstrusus is a lungworm distributed worldwide that affects wild and domestic cats, causing bronchopneumonia of varying intensity. Snails serve as intermediate hosts. The aim of the present study was to assess the larval development of A. abstrusus in R. decollata snails and to investigate its potential as an intermediate host. For this purpose, first-stage larvae (L1) of A. abstrusus were obtained from the faeces of naturally infected cats. Doses of 500 L1/snail were given to 24 R. decollata snails, placed on the soil of the breeder chamber, and maintained under laboratory conditions. Three snails were killed at 8, 10, 12, 16, 22, 26, 45 and 55 days post-infection (dpi), and the muscular foot and visceral body were separately digested by an artificial digestion technique. The morphometric parameters of different larval stages were recorded. The mean number of larvae reaching the infective stage at the end of the study (L3) was 262 larvae/snail. The greatest development to L3 was recorded from days16 to 55 pi, during which the isolation was maximum. A. Abstrusus L3 were isolated from the viscera, but isolation from the snail foot was significantly higher. Our results showed for the first time the ability of A. Abstrusus larvae to develop in R. decollata, thus serving as a potential intermediate host.

The cockroach Periplaneta americana as a potential paratenic host of the lungworm Aelurostrongylus abstrusus.

INTRODUCTION: Aelurostrongylus abstrusus is a well-known nematode affecting the respiratory system of felids worldwide. Snails and slugs act as intermediate hosts of this parasite, whereas rodents, birds and reptiles may serve as paratenic hosts. Periplaneta americana, the American brown cockroach, shares the same habitat and ecological features (e.g. nocturnal activity) with both snails and cats. The aim of this study was to evaluate the capability of P. americana to maintain alive A. abstrusus third stage larvae (L3s) after artificial inoculation. MATERIAL AND METHODS: Twenty-five specimens of P. americana were infected with 100 A. abstrusus L3s collected from experimentally infected Cornu aspersum snails, whereas five specimens were used as control group. After the infection, cockroaches were maintained in individual plastic boxes until dissection for the presence of L3s at 1 (T1), 5 (T5), 10 (T10), 15 (T15), and 20 (T20) days post-infection. RESULTS: Except for T15, alive A. abstrusus L3s (n = 63) were found at all time-points, being 26, 19, 16 and 2 L3s retrieved at T1, T5, T10 and T20, respectively. Eleven (17.4%) L3s were found within the digestive tract, 10 (15.9%) in other-than-digestive organs and 42 (66.7%) in the exoskeleton and associated tissues. Nine out of the twenty-five experimentally inoculated cockroaches (36%) died soon after the artificial infection (T1), while in the control group, two out of the five (40%) died before the end of the study (T15) with no difference in the mortality rate between groups. DISCUSSION: Results of this study suggest that P. americana could act as a paratenic host of A. abstrusus. Periplaneta americana cockroaches, have a ubiquitous distribution and may be preyed by cats, representing a potential source of infection to cats living in endemic areas.

Prevalence of helminth and coccidian parasites in Swedish outdoor cats and the first report of Aelurostrongylus abstrusus in Sweden: a coprological investigation.

BACKGROUND: This study was performed in order to gather recent epidemiological data on feline endoparasites in Swedish cats. Faecal samples from 205 outdoor cats were collected by their owners and submitted to the National Veterinary Institute for analysis. The study population was comprised of cats with access to an outdoor environment and with no history of anthelmintic treatment within the last 3 months. Intestinal parasites were detected with a centrifugal flotation technique and Baermann larval sedimentation was performed to detect metastrongylid lungworms. Eggs, larvae and oocysts were identified morphologically by microscopic examination. The following information was collected from cat owners: breed, sex, age, anthelminthic medication last used, observation of cestode proglottids and residential address. RESULTS: Endoparasites were detected in 25% of samples. Eggs of Toxocara cati were found in 21% of samples, followed by taeniid eggs (4%), oocysts of Cystoisospora felis/C. rivolta and capillarid eggs (both 1%). One cat tested positive for Toxoplasma gondii-like oocysts. Larvae of Aelurostrongylus abstrusus were detected in one cat, which is the first published observation of this parasite in Sweden. CONCLUSIONS: The occurrence of intestinal parasites is rather high in outdoor cats in Sweden, which could indicate the need for more intensive deworming routines in the population. Clinical practitioners should be aware of the possible occurence of A. abstrusus in Swedish cats when considering potential causes of respiratory problems in cats in the future.

Occurrence and clinical significance of Aelurostrongylus abstrusus and other endoparasites in Danish cats.

Feline endoparasites are highly prevalent worldwide and may cause a variety of clinical signs in infected cats. Prevalence rates are dynamic and there is limited knowledge of the current prevalence in Denmark and the clinical manifestation and significance of especially the lungworm Aelurostrongylus abstrusus. This study investigated the total and local prevalence of Aelurostrongylus abstrusus and other endoparasites in Danish cats. The clinical significance of feline aelurostrongylosis was also examined through identification of frequency and severity of selected clinical signs. Faecal samples (n=327) and clinical data (n=312) were collected from August to October 2015, primarily from outdoor cats located at shelters distributed across Denmark. A modified Baermann method and a concentration McMaster technique was used to diagnose A. abstrusus first stage larvae and eggs/oocysts of other endoparasites. The total A. abstrusus prevalence was 8.3% [95% CI: 5.6-11.9] but local prevalence rates varied from 0% [95% CI: 0.0-8.8] to 31.4% [95% CI: 16.9-49.3]. A rural habitat appeared to increase the risk of A. abstrusus and this accounted for most of the local variation. Furthermore, the risk of infection was lower in kittens younger than 11 weeks compared to older cats (p=0.002). The cats were also infected with Toxocara cati (44.4% [95% CI: 38.3-50.7]), taeniid species (8.9% [95% CI: 5.7-13.0]), Capillaria aerophila (3.1% [95% CI: 1.3-6.0]), Aonchotheca putorii (3.9% [95% CI: 1.9-7.0]), Cystoisospora felis (3.1% [95% CI: 1.3-6.0]) and Cystoisospora rivolta (2.3% [95% CI: 0.9-5.0]), but there was no difference in local distribution. Co-infection was common, as 66.7% of A. abstrusus infected cats were also infected with one or more other parasites, the most common being T. cati. However, none of these parasites were significantly associated with A. abstrusus. The vast majority of the A. abstrusus infected cats displayed mild to moderate clinical signs. The main symptoms associated with the infection were increased sound on auscultation of the lungs (p=0.002), increased respiratory rate (p=0.02), coughing (p=0.007) and enlarged mandibular lymph nodes (p=0.002). None of these symptoms were associated with T. cati or C. aerophila which may also affect the lungs. This supports that the symptoms may be related to A. abstrusus and that aelurostrongylosis should be considered an important differential diagnosis in any feline respiratory patient.

Evaluation of different methods for the experimental infection of the land snail Helix aspersa with Aelurostrongylus abstrusus lungworm.

The laboratory maintenance of parasitic life cycles is crucial to support research in many fields of parasitology. The land snail Helix aspersa (syn. Cornu aspersum), an intermediate host of feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior, is adopted to produce infective stages of those nematodes in laboratory condition. The aim of this study was to compare the most common methods of experimental infection of H. aspersa with first stage larvae (L1) of A. abstrusus (i.e., contact of the snail foot with the L1) with the injection of these larvae in the foot of the snail, instrumental to reduce the infection time and to maximize the output of third-stage larvae (L3). Three groups (i.e., A, B, C) of 15 H. aspersa snails were infected with L1 of A. abstrusus (n=250 for each snail), whereas a fourth group (group D) was not infected (control). Snails were individually placed for 48h on a microfilm containing L1 (group A), on a potato slice previously irrigated with a suspension of L1 (group B), or they were inoculated by injection of L1 in the posterior-ventral portion of the foot (group C). Eighteen days after the infection all snails were analyzed and tissues were digested to recover L3. No difference in mortality rate was recorded among snail groups and the mean number of retrieved L3 was significantly larger in group C (71.5±52.9) compared to group B (38.2±44.9; p=0.0161) and group A (19±23.3; p<0.0001). The injection of A. abstrusus L1 in the foot of H. aspersa proved to be a fast, easy to apply and effective method, resulting in the largest number of infective larvae retrieved.

Determinants and effects of sinus worm Skrjabingylus nasicola (Nematoda: Metastrongyloidae) infestation in invasive American mink Neovison vison in Germany.

Skrjabingylus nasicola (Leuckart, 1842) are geographically widespread nematodes that parasitize the nasal and frontal sinus cavities of smaller mustelids. As most prior work was solely based on the analysis of bone injuries of museum skull, little is known about the determinants and effects of infestation in the host species. Working on fresh skulls, we aimed to analyze infestation patterns in American mink (Neovison vison Schreber, 1777) from nine study areas in northern Germany and to identify factors that explained infestation prevalence and intensity in the host species. The prevalence (46.7-62.9 %) and infestation intensity values (4.5-10.89 nematodes) reported here were relatively large, especially compared to other American mink populations in Europe. Considering mink diet, our study sites probably harbored a larger number of infested paratenic hosts and climate did not have a substantial negative influence on survival of S. nasicola larvae. We did not observe any significant sex-age differences in either prevalence or intensity of S. nasicola infestation. We did not find a negative impact of an infestation on the host animals' body weight, confirming prior results that the parasite is not a significant mortality factor in mustelids. Our study suggests that this holds even outside the native distributional range where the host's defenses might not be optimally adapted to an autochthonous parasite.

Efficacy and persistent activity of moxidectin against natural Muellerius capillaris infection in goats and pathological consequences of muelleriosis.

The effect of moxidectin against natural Muellerius capillaris infection in goats was evaluated in this study. Long-acting moxidectin at a single dose of 1 mg kg(-1) body weight was administered to an entire flock (n=10) of goats. The individual faecal larval count reduction was applied as an indicator of treatment efficacy. A significant reduction (>98%) in larval counts was observed in all surveyed animals 14 days after drug administration. Moxidectin demonstrated persistent activity in this study; the mean faecal larval count reduction was 99.1% ± 1.8 on day 77 of the treatment. Macroscopic abnormalities and histological changes in the lungs of two infected goats were evident during the post-mortem examination. The pathological consequences of M. capillaris infection were observed even three months after parasite elimination. The results of this study indicate that moxidectin is a highly effective anthelmintic agent for the control of muelleriosis in goats. This drug provides animals with fifteen weeks of protections against M. capillaris reinfection.

Lung parasites of the genus Metastrongylus Molin, 1861 (Nematoda: Metastrongilidae) in wild boar (Sus scrofa L., 1758) in Central-Italy: An eco-epidemiological study.

The respiratory tracts of 57 wild boars (Sus scrofa L. 1758) hunted in central Italy during the 2011/2012 hunting season were examined to detect the presence of lung worms. Fifty-five out of 57 animals (96,5%) were positive. Five species of Metastrongylus were detected and their prevalence was as follows: Metastrongylus asymmetricus Noda, 1973 (91.2%), Metastrongylus confusus Jansen, 1964 and Metastrongylus salmi Gedoelst, 1923 (87.7%), Metastrongylus apri Gmelin, 1790 (80.7%), Metastrongylus pudendotectus Vostokov, 1905 (70.2%). In most cases multi-species infection was observed. The highest parasite load was found in young animals (<1 year old). The Metastrongylus genus sex ratio (M/F) had a range from 1:4.8 to 1:1.5 in favor of females. The Simpson and Shannon-Wiener indices showed a moderate uniformity in parasite community composition. The Fager index highlighted a high degree of affinity among all pairs of selected parasites. The whole parasite population showed an aggregate distribution. Our findings confirm that these parasites are widespread in the wild boar population. The establishment of outdoor domestic pig farming in the same area of the game preserve could pose the risk of infection to domestic animals. Further studies will be needed to understand the factors involved in the presence and prevalence of the intermediate host as well as the population dynamics of Metastrongylus spp.