Larval development of Aelurostrongylus abstrusus (Nematoda, Angiostrongylidae) in experimentally infected Cernuella (Cernuella) virgata (Mollusca, Helicidae)

Molecular prevalence, phylogenetic characterization, and epidemiological risk factors of pulmonary nematodes in domestic cats in Türkiye

Aelurostrongylus abstrusus, Oslerus rostratus, and Troglostrongylus brevior are nematodes found in the respiratory system of domestic cats and cause a variety of symptoms. All three parasites use the same hosts and niches, and the morphological measurements of their L1s excreted in faeces overlap with each other. In this study, 300 cats brought to Ondokuz Mayıs University Veterinary Teaching Animal Hospital were screened for lungworms by morphological measurements and molecular analyses. The prevalence of the lungworms was found as 1.33% (4/300) for A. abstrusus, 0.66% (2/300) for O. rostratus, and 0.33% (1/300) for T. brevior. Molecular identification of A. abstrusus, T. brevior, and O. rostratus in domestic cats was carried out for the first time in Türkiye within the present study. This study also reveals the risk factors of lungworm positivity in domestic cats in Türkiye.

The Influence of Temperature on the Larval Development of Aelurostrongylus abstrusus in the Land Snail Cornu aspersum

The metastrongyloid Aelurostrongylus abstrusus has an indirect lifecycle involving gastropod intermediate hosts. The widespread snail Cornu aspersum is an efficient intermediate host of A. abstrusus. As the temperature may influence the developmental rate of metastrongyloids from first (L1) to the third infective larval stage (L3) inside molluscs, this study evaluated the effect of two controlled temperatures on the development of A. abstrusus in C. aspersum. Overall, 300 snails were infected with 500 L1 of A. abstrusus and kept at ∼25 °C. Fifteen days post infection (D15), the overall developmental rate to L3 (0.8%) was assessed in a subset of 20 snails. The remaining gastropods were divided in 2 groups, i.e., 180 still kept at ∼25 °C (G1) and 100 hibernated at ∼4 °C (G2). On D30, the larval development was evaluated in 20 snails from each group, while another batch of 80 snails was selected random from G1 and hibernated at ∼4 °C (G3). The larval developmental rate was determined digesting 20 snails from each of the three groups on D45, D60, and D75. The higher mean developmental rate was registered in G1 (3.8%) compared to G2 (1.9%) and G3 (2.3%), indicating that the development to L3 of A. abstrusus in C. aspersum is positively influenced by the increase of temperature.

New approaches to studying morphological details of intramolluscan stages of Angiostrongylus vasorum

Angiostrongylus vasorum is a pulmonary artery parasite of domestic and wild canid. On molluscs, intermediate host, first stage larvae (L1) are found after the first day of infection, in the 8th L2 and in the 30 th L3. It was evaluated L1, L2 and L3 recovered by Baermann technique from Achatina fulica infected with 1000 L1. Fifty larvae/stage were incubated with antibodies anti-β-tubulin, anti-α-tubulin, anti- α-actin, anti-β-actin and anti-collagen, and then with Alexa 633. Fifty larvae/stage were observed with picrosirius red and Oil Red O. It was also observed in the anterior region of L1 the beginning of the chitinous stems development, in the initial portion of the intestine and genital primordium. In L2 anterior region, the papillae, chitinous canes juxtaposed to the mouth and intestines bigger than L1. The L3 musculature is well defined, next to the chitinous stems, there are two round distally arranged from each other. It was observed the whole extension of the intestine genital primordium and intense cellularity in the L3 distal portion. With the picrosirius red the L1, L2 and L3 musculature could be observed, as the nerve ganglia on L3. Oil Red O revealed that L1, L2 and L3 store energy on lipid droplets.

Intermediate gastropod hosts of major feline cardiopulmonary nematodes in an area of wildcat and domestic cat sympatry in Greece

Background

The metastrongyloid nematodes Aelurostrongylus abstrusus, Troglostrongylus brevior and Angiostrongylus chabaudi are cardiopulmonary parasites affecting domestic cats (Felis catus) and wildcats (Felis silvestris). Although knowledge on these nematodes has been improved in the past years, gaps in our knowledge of their distribution and role of gastropods as intermediate hosts in Europe still exist. This study reports on the presence of these nematodes and their intermediate hosts in an area in Greece where domestic cats and wildcats occur in sympatry.

Methods

Terrestrial gastropods were collected in the field and identified morphologically and by mitochondrial DNA-sequence analysis. Metastrongyloid larvae were detected by artificial digestion, morphologically identified to the species and stage level and their identity was molecularly confirmed.

Results

Aelurostrongylus abstrusus was found in the snails Massylaea vermiculata and Helix lucorum, T. brevior in the slug Tandonia sp., and A. chabaudi in the slug Limax sp. and the snails H. lucorum and M. vermiculata.

Conclusions

To the best of our knowledge this study provides the first reports of (i) terrestrial gastropods being naturally infected with A. chabaudi, (ii) T. brevior naturally infecting terrestrial gastropods in Europe, and (iii) A. abstrusus naturally infecting terrestrial gastropods in Greece. Furthermore, the present study describes for the first time developmental stages of A. chabaudi and T. brevior in naturally infected gastropods. The biological characteristics of various intermediate gastropod hosts that could influence the distribution and expansion of feline cardiopulmonary nematodes are discussed, along with epizootiological implications and perspectives.

The invasive giant African snail Lissachatina fulica as natural intermediate host of Aelurostrongylus abstrusus, Angiostrongylus vasorum, Troglostrongylus brevior, and Crenosoma vulpis in Colombia

BACKGROUND

Several metastrongyloid lungworms are unreported pathogens in Colombia. Angiostrongylus vasorum and Crenosoma vulpis target the cardiopulmonary system of domestic and wild canids. Aelurostrongylus abstrusus and Troglostrongylus brevior infect felids and considering that six wild felid species exist in Colombia, knowledge of feline lungworm infections is important for their conservation. The zoonotic metastrongyloids Angiostrongylus costaricensis and Angiostrongylus cantonensis can cause severe gastrointestinal and neurological diseases. Angiostrongylus costaricensis has been reported in Colombia, while Ang. cantonensis is present in neighbouring countries. Research on the epidemiology of metastrongyloids in Colombia and South America more broadly requires evaluating the role that gastropods play as intermediate hosts in their life cycles. This study assessed the prevalence of metastrongyloid larvae in populations of the invasive giant African snail, Lissachatina fulica, in Colombia.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 609 Lissachantina fulica were collected from 6 Colombian municipalities. The snails were then cryo-euthanized, artificially digested and the sediments examined microscopically for the presence of metastrongyloid larvae. Based on morphological characteristics 53.3% (56/107) of the snails from Puerto Leguízamo (Department of Putumayo) were infected with Ael. abstrusus larvae, 8.4% (9/107) with Ang. vasorum larvae, 6.5% (7/107) with T. brevior larvae and 5.6% (6/107) with C. vulpis larvae, being the region with highest prevalences of the four species. Snails from Andes (Department of Antioquia) and Tulúa (Department of Valle del Cauca) were positive for Ang. vasorum larvae with a prevalence of 4.6 (11/238) and 6.3% (4/64), respectively. Species identifications were confirmed by PCR and sequencing.

CONCLUSIONS/SIGNIFICANCE

This epidemiological survey reports for first time the presence of Ael. abstrusus, T. brevior, C. vulpis and Ang. vasorum in L. fulica in a number of regions of Colombia.

Prevalence of Angiostrongylus vasorum, Aelurostrongylus abstrusus and Crenosoma vulpis larvae in native slug populations in Germany

Metastrongyloid parasites represent sparsely studied parasites of dogs and cats in Germany. Recent European surveys indicate that these parasites are spreading in Europe. Actual data on prevalence of Angiostrongylus vasorum in dogs and foxes reveal several endemic foci in Germany. However, actual data on the prevalence of A. vasorum and other metastrongyloid lungworm larvae in a wide range of slug and snail intermediate hosts, such as Arion lusitanicus, are missing for Germany. To fill this gap, we conducted an epidemiological survey on native German slugs in selected regions of Hesse and Rhineland-Palatinate. The focus was on slugs, because in study areas slugs appear to be more abundant than snails. Slugs were collected throughout different seasons of the year in areas that were previously proven to be hyperendemic for A. vasorum fox infections. Overall, a total of 2701 slugs were collected and examined for lungworm larvae via artificial digestion. The number of A. vasorum larvae per slug varied considerably (1-546 larvae per specimen). Some hotspot areas with high A. vasorum prevalence in slugs (up to 19.4%) were identified. The overall A. vasorum prevalence varied with season with largest number of slugs infected in summer (9.1%) and lowest number in winter (0.8%). The current study revealed a total A. vasorum prevalence of 4.7% in slugs based on microscopic analyses. Confirmation of lungworm species was made by specific duplex-real-time PCRs. Hence, these data demonstrate that final hosts are at a permanent risk for A. vasorum infections during all seasons when living in investigated areas. Besides A. vasorum, other lungworm larvae were also detected, such as Crenosoma vulpis (the fox lungworm, 2.3%) and Aelurostrongylus abstrusus (feline lungworm, 0.2%).

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.

Lungworms and gastrointestinal parasites of domestic cats: a European perspective

With the exception of Aelurostrongylus abstrusus, feline lungworms have been poorly studied. Information on their distribution is patchy and mostly limited to case reports. In this study, the occurrence of feline lungworms and co-infecting gastrointestinal parasites has been investigated in 12 European countries (i.e. Austria, Belgium, Bulgaria, France, Greece, Hungary, Italy, Portugal, Romania, Spain, Switzerland and the United Kingdom). An average of 10 domestic cats, with regular outdoor access, was sampled each month for 12months, and freshly passed faeces were collected. Stools were processed using a McMaster assay and a quantitative Baermann-Wetzel method. Animals positive for lungworms and/or gastrointestinal parasites were treated with a formulation containing fipronil, (S)-methoprene, eprinomectin, and praziquantel (Broadline®, Merial), and re-sampled 28days post-treatment. The association between lungworm infection and risk factors was analysed using statistical medians/means and the efficacy of the treatment against each lungworm species was assessed. Of 1990 cats sampled, 613 (30.8%) were positive for at least one parasite, while 210 (10.6%) were infected by lungworms. The prevalence of lungworm infection varied between the sampled sites, with the highest recorded in Bulgaria (35.8%) and the lowest in Switzerland (0.8%). None of the cats from Austria or the United Kingdom were infected by lungworms. Aelurostrongylus abstrusus was the species most frequently detected (78.1%), followed by Troglostrongylus brevior (19.5%), Eucoleus aerophilus (14.8%) and Oslerus rostratus (3.8%). The overall efficacy of the treatment was 99% for A. abstrusus and 100% for T. brevior, O. rostratus and E. aerophilus. Data presented provide a comprehensive account of the diagnosis, epidemiology and treatment of feline lungworms in Europe, as well as of the occurrence of co-infections by gastrointestinal parasites.

Natural infection of the feline lungworm Aelurostrongylus abstrusus in the invasive snail Achatina fulica from Argentina

The giant African snail Achatina fulica is an invasive mollusk native to Africa, the first record in Argentina was in Puerto Iguazú, in northeastern Argentina in 2010. Recently it was reported in Corrientes Province. This snail can act as an intermediate host of Metastrongyloidea nematodes of importance in public health as: Angiostrongylus cantonensis, Angiostrongylus costaricensis and Angiostrongylus vasorum. Taking into account the presence of A. fulica in Argentina, the objectives of this study is to assess the presence of Metastrongyloidea nematodes in this mollusk species in Puerto Iguazú, Misiones, close to the international border with Brazil and Paraguay. A total of 451 samples were collected from February 2014 to November 2015. The snails were processed using a digestion technique to recover the parasites. A total of 206 nematodes larvae were founded in the digestion solution of 10 hosts (P=2%; MA=0.5; MI=21). Third larval stage (L3) nematodes identified as Aelurostrongylus abstrusus were founded parasitizing the snails. No other larval stage was observed. This species has veterinary importance because it causes 'aelurostrongilosis', also known as feline strongyloidosis. This study constitutes the first record of a Metastrongyloidea nematode in A. fulica in Argentina and also highlights the susceptibility of this mollusk as intermediate host of other helminthes of health importance. The present study suggests that there is a need to establish an epidemiological monitoring system in order to prevent the possible installation of an infected mollusks focus.

Single and mixed feline lungworm infections: clinical, radiographic and therapeutic features of 26 cases (2013-2015)

Objectives The aim of this study was to retrospectively describe clinical, radiographic and therapeutic features of feline lungworm infection. Methods Medical records of cats with lungworm diagnosis, thoracic radiography and without concurrent diseases between 2013 and 2015 were reviewed. Collection of data included physical examination, haematology, serum biochemistry, therapy with a variety of anthelmintics and outcomes. Results Thirty-seven records were recovered and 26 were included in the study. Single infections by Aelurostrongylus abstrusus (n = 15), Troglostrongylus brevior (n = 3) and Capillaria aerophila (n = 1) and coinfections by T brevior/ A abstrusus (n = 6) and T brevior/ C aerophila (n = 1) were diagnosed. The most common respiratory signs were coughing (n = 12), increased vesicular sounds (n = 10), dyspnoea (n = 9), such as laboured breathing, orthopnoea or open-mouth breathing, and tachypnoea (n = 6). Two cats were subclinically infected. The most common laboratory abnormality was anaemia (n = 7). Radiographic patterns recorded were interstitial (n = 24), bronchial (n = 21), alveolar (n = 10) and vascular (n = 2). Twenty-five cats had a complete recovery within 2-6 weeks of therapy. One kitten died 7 days after the diagnosis. Conclusions and relevance Lungworms should always be included in the differential diagnosis in cats living in endemic areas and presenting with respiratory signs and radiographic abnormalities. A copromicroscopic examination should be considered as the first diagnostic step for all cats at risk of lungworm infections. In most cases, timely therapy with a variety of anthelmintics guarantees recovery.

Diagnosis and management of lungworm infections in cats: Cornerstones, dilemmas and new avenues

PRACTICAL RELEVANCE

Respiratory parasites infecting domestic cats are attracting increased attention in feline clinical practice. In addition to the most commonly recognised 'cat lungworm' Aelurostrongylus abstrusus, Troglostrongylus brevior and Capillaria aerophila are now considered important pathogens of the respiratory tract of cats.

GLOBAL IMPORTANCE

These parasites are being increasingly diagnosed in several regions of the world and a continuous update on epidemiological changes and advances in diagnosis and control is of practical importance.

AIMS

This article reviews current knowledge of lungworms affecting cats, with a special focus on recent insights into diagnosis and management of the diseases they cause. The article also explores some potential new avenues for control of feline parasitic respiratory diseases, and highlights some key areas requiring further research.

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.

Lungworm disease in cats: ABCD guidelines on prevention and management

OVERVIEW

Cardiopulmonary nematodes are emerging parasites of cats in Europe. A number of helminth parasites may be involved. The most prevalent lungworm in domestic cats is Aelurostrongylus abstrusus. Oslerus rostratus and Troglostrongylus species are found mainly in wild cats. The trichurid Capillaria aerophila has a low host specificity and is not uncommon in cats. Additionally the lung flukes Paragonimus species are reported in many species outside of Europe, including cats.

CLINICAL SIGNS

Lungworm infections may be asymptomatic, or cause mild to severe respiratory signs, dependent on the worm species and burden; mixed infections are observed. Kittens can be vertically infected and may develop a more severe disease. Affected cats show a productive cough, mucopurulent nasal discharge, tachypnoea, dyspnoea and, in severe cases, respiratory failure and death.

MANAGEMENT

Early diagnosis and treatment greatly improves the prognosis. First-stage larvae can be easily detected in fresh faecal samples; the Baermann migration method is the enrichment technique of choice, but takes 24 h. Lungworm larvae can be found in tracheal swabs and bronchoalveolar lavage fluid, but with less sensitivity than in faeces. Molecular methods have been developed that exhibit high specificity and sensitivity, and allow diagnosis in the prepatent phase. Treatment options include fenbendazole paste, milbemycin oxime/praziquantel and various spot-on formulations. Severe cases should receive prompt medical care in an intensive care unit.

PREVENTION

Avoiding predation is at present the only preventive measure for pulmonary worms with indirect life cycles.

ZOONOTIC RISK

C aerophila has zoonotic potential, causing severe pulmonary disease in humans. Some Paragonimus species are also of zoonotic concern.

Development of the feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior in Helix aspersa snails

Aelurostrongylus abstrusus (Strongylida, Angiostrongylidae) and Troglostrongylus brevior (Strongylida, Crenosomatidae) are regarded as important lungworm species of domestic felids, with the latter considered an emerging threat in the Mediterranean region. The present study aimed to assess their concurrent development in the mollusc Helix aspersa (Pulmonata, Helicidae). Thirty snails were infested with 100 first-stage larvae (L1) of A. abstrusus and T. brevior, isolated from a naturally infested kitten. Larval development was checked by digesting five specimens at 2, 6 and 11 days post infestation. Larvae retrieved were morphologically described and their identification was confirmed by specific PCR and sequencing. All H. aspersa snails were positive for A. abstrusus and T. brevior, whose larval stages were simultaneously detected at each time point. In addition, snails were exposed to outdoor conditions and examined after overwintering, testing positive up to 120 days post infestation. Data herein presented suggest that A. abstrusus and T. brevior develop in H. aspersa snails and may eventually co-infest cats. Data on the morphology of both parasitic species in H. aspersa provide additional information on their development and identification, to better understand the population dynamics of these lungworms in receptive snails and paratenic hosts.

Intermediate and paratenic hosts in the life cycle of Aelurostrongylus abstrusus in natural environment

The cat lungworm Aelurostrongylus abstrusus affects the domestic cats and other felids all over the world. Feline aelurostrongylosis is of importance in clinical feline medicine. Snails and slugs are the intermediate hosts, but the cat is probably infected by eating paratenic hosts, e.g., rodents, birds, amphibians and reptiles. Herein we present the first finding of A. abstrusus in a naturally infected invasive synantropic slugs Arion lusitanicus (intermediate host) and wild living rodents Apodemus agrarius (paratenic host). The results confirm the usefulness of molecular approaches for investigating the biology, ecology and epidemiology of A. abstrusus, the agent of feline aelurostrongylosis.

Feline lungworms: what a dilemma

Aelurostrongylus abstrusus is regarded as the major lungworm infecting Felis catus, although other, albeit poorly studied, nematodes have been described from the respiratory system of domestic cats. Recent records of these neglected parasites have renewed the attention of the scientific community, but their actual role in respiratory disease in cats is blurred. The epidemiology, pathogenic role, and diagnosis of Troglostrongylus spp., Oslerus rostratus, and Capillaria aerophila in domestic cats are far from being clarified. Indeed, recent studies have provided novel information but have also given rise to relevant doubts. We discuss here the state of current knowledge regarding felid lungworms together with the dilemmas recently roused in the scientific literature.

Larval development of the feline lungworm Aelurostrongylus abstrusus in Helix aspersa

The cat lungworm Aelurostrongylus abstrusus affects the domestic cat and other felids all over the world. Feline aelurostrongylosis is of importance in clinical feline medicine and is gaining more and more attention for the present expansion in the geographical range of A. abstrusus. Global warming and changes in phenology of snail intermediate hosts have been incriminated in this spreading. Helix aspersa, a potential vector of A. abstrusus, is endemic in most regions of the world, where it has become recently a pest outside its native Mediterranean range. The present work evaluated key features of larval development of A. abstrusus in H. aspersa at two different temperature conditions. The results showed that A. abstrusus may reach the infective stage in muscular foot and viscera of H. aspersa and that environmental temperatures may influence the biological cycle of the cat lungworm. In particular, the higher the average temperature, the higher the rate of larval development, i.e., about 50% of larvae of A. abstrusus reached the infective stage between temperatures of 18.8-29.5 °C, while only 17.8% of larvae completed their development at temperatures of 6.7-22 °C. Biological and epidemiological implications are discussed.

Angiostrongylus vasorum: Experimental Infection and Larval Development in Omalonyx matheroni

The susceptibility and suitability of Omalonyx matheroni as an intermediate host of Angiostrongylus vasorum and the characteristics of larval recovery and development were investigated. Mollusks were infected, and from the 3rd to the 25th day after infection, larvae were recovered from groups of 50 individuals. The first observation of L2 was on the 5th day, and the first observation of L3 was on the 10th day. From the 22nd day on, all larvae were at the L3 stadium. Larval recovery varied from 78.2% to 95.2%. We found larval development to be faster in O. matheroni than in Biomphalaria glabrata. Our findings indicate that this mollusk is highly susceptible to A. vasorum. Infective L3 were orally inoculated into a dog, and the prepatent period was 39 days. This is the first study to focus on O. matheroni as an intermediate host of A. vasorum.

Nematode cysts and larvae found in Achatina fulica Bowdich, 1822

This study describes the morphology of the nematode cysts and larvae found in Achatina fulica (giant African snail) in Brazil. Sixty snails were collected in Mesquita, Rio de Janeiro State. Fourteen of the snails were naturally infected. The cysts were spherical, pink colored and measured 0.97 to 1.57 mm in diameter. In the majority of cases they had a single larvae involved in amorphous material. A total of 222 encysted larvae were recovered. Of these, 30 were utilized in the morphological study. The length of the larvae varied from 2.57 to 5.8 mm and they were classified as small--up to 3.5 mm; medium--from 3.53 to 4.5 mm; and large--greater than 4.52 mm. The average length of the larvae in the three groups was 2.85, 3.87 and 5.23 mm, respectively. The larval cuticle was white, shiny and transversally striated until the posterior end of the body. At the anterior end there is a mouth with three lips, with amphids and papillae, followed by a muscular esophagus with average length of 0.61 mm, terminating in an esophageal bulb and having a nerve ring in the middle third of the esophagus, and an intestine with an opening near the posterior end. The tail begins from this opening and has two types of ends: short and abrupt or long and gradually tapering. The difference in the tail end can suggest sexual dimorphism, although no primordial reproductive structures were observed. These characteristics were not sufficient to identify the larvae, so there is a need for further study.

Use of the FLOTAC technique for the diagnosis of Aelurostrongylus abstrusus in the cat

Aelurostrongylus abstrusus is a lungworm of the domestic cats distributed worldwide. Its presence, however, is often underestimated due to limitation of common coprological diagnostic techniques. The present study reports, for the first time, the use of the FLOTAC technique for A. abstrusus diagnosis in feline faecal samples with results compared to the following three standard copromicroscopic techniques: the Baermann technique, the McMaster technique and the Wisconsin technique. The comparison study showed that the FLOTAC technique produced mean larvae per gram of faeces significantly (P<0.05) greater than that produced by the other more widely used diagnostic tools. Thus, the FLOTAC technique can be utilised for quantifying lungworm larva burdens in feline faecal samples because of its high sensitivity, as already shown for various parasites of veterinary and human importance.

Prevalence study of the lungworm Aelurostrongylus abstrusus in stray cats of Portugal

In this study we have investigated the prevalence of aelurostrongylosis, one of the most common feline pulmonary parasitic diseases, in cats from the north-west region of Portugal. For this purpose, 97 faecal samples were collected from cats at risk of being infected by Aelurostrongylus abstrusus in an animal shelter and in a municipal facility. Using the Baermann–Wetzel coprological technique, faecal shedding of first stage larvae (L1) was detected in 17.4% of the cats. Based on this result, it can be concluded that this lungworm infection seems to be common among feral cats in the north-west region of Portugal, in spite of the fact that clinical aelurostrongylosis is not frequently diagnosed by feline practitioners in the area. This parasitic disease should be included in the differential diagnosis of cats presenting with coughing or dyspnoea, and it also should be extended to asymptomatic animals with pulmonary nodules detected by image diagnosis.

Diagnostic and clinical implications of a nested PCR specific for ribosomal DNA of the feline lungworm Aelurostrongylus abstrusus (Nematoda, Strongylida)

Aelurostrongylus abstrusus (Nematoda, Strongylida, Metastrongyloidea) is a cosmopolitan parasite of cats and causes severe respiratory distress. Information on the biology and epidemiology of feline aelurostrongylosis is fragmentary, mainly due to the limits inherent in the classical diagnosis. In the present work, a two-step nested PCR based on the use of genetic markers in the second internal transcribed spacer (ITS2) of ribosomal DNA was established for A. abstrusus in different biological samples. Characterization of the ITS2 (321 bp of length) revealed a G+C content of 39.5%. To exploit the sequence difference between the ITS2 of A. abstrusus and those of other common feline endoparasites, specific primers were designed and tested by PCR for their specificities and sensitivities. The PCR assay was validated on a panel of fecal (i.e., feces, flotation supernatant, and Baermann sediment) and pharyngeal swab samples from cats with known histories of lungworm infections, and it showed a specificity of 100% and a sensitivity of up to 96.6%. Also, the nested PCR was able to identify cats that were actually infected but that tested negative by the classical diagnostic methods. This PCR method was shown to be a powerful tool for the molecular diagnosis of feline aelurostrongylosis, overcoming the constraints of the classical diagnosis. The implications of such a molecular tool for further bioepidemiological studies of both intermediate and definitive hosts have been discussed.

Diagnosis and risk factors of Aelurostrongylus abstrusus (Nematoda, Strongylida) infection in cats from Italy

Aelurostrongylus abstrusus (Nematoda, Strongylida) in cats and associated risk factors have been investigated by classical coprology in central (site A) and southern (site B) Italy, i.e. by floatations with sugar and zinc sulphate solutions and a Baermann technique. Overall, 227 individual stool samples (i.e. 162 from site A and 65 from site B) were processed and risk factors were related to infection by binary logistic multiple-regression models. The presence of A. abstrusus was used as the dependent variable and the epidemiological data as independent variables. Twenty-eight (17.3%) and 12 (18.5%) cats were positive for A. abstrusus in sites A and B, respectively, both using the Baermann and flotation with zinc sulphate solution methods. Six and three (from site A and B, respectively) of the infected cats were negative for A. abstrusus when faeces were processed with sugar solution. Stray and free-ranging (P=0.357), young cats (P=0.008) and the presence of respiratory symptoms (P=0.000) were risk factors for A. abstrusus infection. The results suggest that A. abstrusus is spread in Italy. Furthermore, these results possibly include infection in the differential diagnosis of feline respiratory diseases and offer a correct diagnostic approach by using either a Baermann method or flotation with zinc sulphate solution in suspected cases.

Larval development of Neostrongylus linearis (Nematoda, Protostrongylidae) in the mollusc Cochlicella barbara infected and maintained in a subhumid area (north-west Spain) and its possible influence on the infection of small ruminants

Twelve batches of 100 Cochlicella barbara (Mollusca, Helicidae) were deposited monthly, from January to December in plots (0.5 x 0.5 m) with faeces of sheep containing first-stage larvae of Neostrongylus linearis in order to be naturally infected, and another 12 batches acted as uninfected controls. Every 2 weeks dead molluscs were removed from the plots and three to five specimens were examined to study larval development in the snail. Infected and control snails did not differ in their mortality, which may be associated with the low rate of infection of snails. The highest number of molluscs that were infected and the maximum level of infection were observed in batches deposited in summer months. There was a positive correlation between the percentage of infected snails and temperature. Molluscs harboured higher number of infectious third-stage larvae (L3) from mid-spring to mid-autumn and especially in summer months; thus under these climatic conditions and periods small ruminants are more likely to get infected by N. linearis.

Aelurostrongylus abstrusus (cat lungworm) infection in five cats from Italy

Infection by the cat lungworm Aelurostrongylus abstrusus is considered uncommon. Here, the authors report the clinical, diagnostic and therapeutic features of five infections recently observed in Italy. All cats were under 12 months of age. All except one cat had symptomatic infections, with cough, dyspnea, and weight loss with radiographic signs of broncopneumonia. All cats were eosinophilic. Larvae were present in fresh fecal smears and on flotation exam in all cats. Baermann larval recovery permitted definitive identification and, in one case, larvae per gram of feces (lpg) counts. One dose of ivermectin (400 microg/kg) was not effective in one cat, while one dose of selamectin (6 mg/kg) was effective in one of three cases and fenbendazole at 50 mg/kg given daily for 15 days was effective in four of four cases.