Faecal egg count reduction test in goats: Zooming in on the genus level.

The faecal egg count reduction test (FECRT) is the most widely used method to assess treatment efficacy against gastrointestinal nematodes (GIN). Information on genera composition of the GIN community is not available with this test and it is commonly obtained by identifying cultured third-stage larvae (L3) or through molecular assays in the post-treatment survey, but results provided are usually only qualitative or semi-quantitative. The updated WAAVP guidelines now recommend assessing anthelmintic efficacy for each GIN genus/species separately (genus-specific FECRT), but this approach is poorly employed in Europe and in goats especially. For this reason, four FECRT trials were conducted using oxfendazole and eprinomectin in two Italian goat farms. Samples were processed individually using the McMaster technique and then pooled to create two samples from faeces of 5 animals each. Pooled samples were analysed using the McMaster and cultured for seven days at 26°C to obtain L3s. The genus-specific FECRT was based on larval identification, integrating coproculture and FEC results. Larvae were identified as Haemonchus, Trichostrongylus, Teladorsagia, Oesophagostomum / Chabertia and Bunostomum. Molecular assays (a multiplex real-time PCR and two end-point PCRs) were also implemented on pooled samples to support the morphological identification. The Spearmann Rho test confirmed a high correlation between the two approaches (Rho = 0.941 and Rho = 0.914 respectively for Haemonchus and Trichostrongylus, the two most common genera). Both oxfendazole and eprinomectin were effective in one farm, while none in the other farm (FECR = 75.9% and 73.3% respectively). In the second farm, the genus-specific FECRT highlighted a different response to treatment among genera: oxfendazole lacked efficacy against both Haemonchus and Trichostrongylus spp., eprinomectin only against Haemonchus, while all other genera were susceptible to both drugs. This study brings new attention on the importance of adopting a genus-specific approach to identify and quantify differences in susceptibility to anthelmintics among genera in goats, providing support for FECRT interpretation, anthelmintic resistance evaluation and evidence-based GIN control.

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.

Efficacy of Aquatain® Against Culex pipiens Complex and Aedes albopictus in Catch Basins in Italy.

Aquatain® is an alternative larvicide formulation to the currently used larvicides. Its efficacy can be assessed monitoring emerging adults with a floating device that was recently developed for use in catch basins. In this study, the efficacy of Aquatain in controlling Aedes albopictus and Culex pipiens complex was investigated by comparing the adults emerging from 25 treated catch basins with that of 25 control basins in northeastern Italy. Basins were monitored weekly for 9 times and the efficacy was evaluated using the Mann-Whitney U-test and calculating the inhibition of emergence at each sampling. Aquatain was effective in reducing the number of emerging mosquitoes for both species, but its duration was affected by rainfall. Intensive showers (>10 mm daily) seem to reduce the efficacy of the product, allowing an increase in emerging adults after about 2 wk. This finding suggests that climatic factors should be taken into account to decide the right time for reapplication of Aquatain during routine larval treatments.

Fatal Patent Troglostrongylosis In A Litter of Kittens.

Parasitic nematodes affecting the respiratory system of cats are gaining much attention in the scientific community and new knowledge has recently been acquired on their epizootiology, biology, and clinical aspects. In particular, in the past few years different studies have indicated that the metastrongyloid lungworm Troglostrongylus brevior can be vertically transmitted in cats, although information on its basic biology is still poor. The present paper describes a case of troglostrongylosis in a litter of 3 suckling kittens, with a focus on anatomo-pathological and biological features of the infection in 2 of these 3 animals. The third kitten survived the infection and clinical and therapeutic aspects are presented. New insights into the transmission and biology of T. brevior are discussed along with potential strategies for an efficacious treatment and control of this life-threatening parasitosis of cats.

Field Trial To Evaluate Two Different Procedures For Monitoring the Efficacy of Aquatain® Against Culex pipiens and Aedes albopictus IN CATCH BASINS.

Aedes albopictus and Culex pipiens are commonly distributed in Italy and represent the main species found in catch basins. The application of a silicone-based film (e.g., Aquatain®) is a new tool recently introduced for treating catch basins. While the efficacy of Aquatain has been experimentally demonstrated, its use is still lacking an appropriate monitoring procedure. The present study compared the differences in the efficacy of treatment assessment between a newly developed floating system (FS), which was designed to collect emerging adults, with the standard dipper procedure, used for estimating the abundance of mosquito larvae. Forty catch basins, half treated with Aquatain and half untreated (control basins), were monitored weekly using dipper (10 treated + 10 control basins) or FS (10 + 10) 5 times after 2 subsequent treatments. Both monitoring procedures recorded high percentages of larvae and adult reduction for the 1st 1-3 wk after treatments, confirming the simultaneous activity of Aquatain against all stages of mosquitoes. Differences in adult emergence were recorded also when monitoring of larvae was ineffective, suggesting that the newly developed FS is a promising method for assessing the efficacy of monomolecular films in catch basins.

Evaluation of Alternative Methods for Testing the Bioefficacy of Household Ambient Insecticide Products Against Aedes albopictus.

Ambient insecticides are receiving increasing attention in many developed countries because of their value in reducing mosquito nuisance. As required by the European Union Biocidal Products Regulation 528/2012, these devices require appropriate testing of their efficacy, which is based on estimating the knockdown and mortality rates of free-flying (free) mosquitoes in a test room. However, evaluations using free mosquitoes present many complexities. The performances of 6 alternative methods with mosquitoes held in 2 different cage designs (steel wire and gauze/plastic) with and without an operating fan for air circulation were monitored in a test room through a closed-circuit television system and were compared with the currently recommended method using free mosquitoes. Results for caged mosquitoes without a fan showed a clearly delayed knockdown effect, whereas outcomes for caged mosquitoes with a fan recorded higher mortality at 24 h, compared to free mosquitoes. Among the 6 methods, cages made of gauze and plastic operating with fan wind speed at 2.5-2.8 m/sec was the only method without a significant difference in results for free mosquitoes, and therefore appears as the best alternative to assess knockdown by ambient insecticides accurately.

Fatal Angiostrongylus dujardini infection in callitrichid monkeys and suricates in an Italian zoological garden.

This paper reports four fatal cases of metastrongylid nematode Angiostrongylus dujardini infection observed in a Saguinus oedipus and a Callimico goeldii monkey and in two suricates (Suricata suricatta). All animals were kept in captivity in a zoo of central Italy. The two monkeys died with no premonitory signs, while the two-month-old suricates showed malaise, anorexia and tachypnea for a few days prior to death. Cardiomegaly and/or granulomatous pneumonia were the major anatomo-pathological findings. Inflammatory lesions were observed in the liver, heart and kidney of the suricates at histology. A. dujardini diagnosis was confirmed through both morphological identification of adult worms recovered at necropsy and molecular characterization of larvae in tissue samples. Callitrichidae and suricates are active predators and maintain their hunting behaviour in captivity and it is then likely that they were exposed to infection by preying on parasitized gastropods, intermediate hosts of A. dujardini, entering zoo enclosures from the surrounding environment. This is the first report of A. dujardini in Italy and in S. suricatta.

Anthelmintic resistance to ivermectin and moxidectin in gastrointestinal nematodes of cattle in Europe.

Anthelmintic resistance has been increasingly reported in cattle worldwide over the last decade, although reports from Europe are more limited. The objective of the present study was to evaluate the efficacy of injectable formulations of ivermectin and moxidectin at 0.2 mg per kg bodyweight against naturally acquired gastro-intestinal nematodes in cattle. A total of 753 animals on 40 farms were enrolled in Germany (12 farms), the UK (10 farms), Italy (10 farms), and France (8 farms). Animals were selected based on pre-treatment faecal egg counts and were allocated to one of the two treatment groups. Each treatment group consisted of between 7 and 10 animals. A post-treatment faecal egg count was performed 14 days (±2 days) after treatment. The observed percentage reduction was calculated for each treatment group based on the arithmetic mean faecal egg count before and after treatment. The resistance status was evaluated based on the reduction in arithmetic mean faecal egg count and both the lower and upper 95% confidence limits. A decreased efficacy was observed in half or more of the farms in Germany, France and the UK. For moxidectin, resistance was confirmed on 3 farms in France, and on 1 farm in Germany and the UK. For ivermectin, resistance was confirmed on 3 farms in the UK, and on 1 farm in Germany and France. The remaining farms with decreased efficacy were classified as having an inconclusive resistance status based on the available data. After treatment Cooperia spp. larvae were most frequently identified, though Ostertagia ostertagi was also found, in particular within the UK and Germany. The present study reports lower than expected efficacy for ivermectin and moxidectin (based on the reduction in egg excretion after treatment) on European cattle farms, with confirmed anthelmintic resistance on 12.5% of the farms.

Decreased strongyle egg re-appearance period after treatment with ivermectin and moxidectin in horses in Belgium, Italy and The Netherlands.

The objective of the present study was to evaluate the efficacy of an oral treatment with ivermectin (IVM) or moxidectin (MOX) against gastro-intestinal strongyles in naturally infected horses by performing a faecal egg count reduction test (FECRT) and by monitoring the egg reappearance period (ERP) after treatment. Therefore, a field efficacy study with a randomised complete block design for each study site was conducted, with the individual animal as the experimental unit. At least 10 study sites in Italy, Belgium and The Netherlands were selected and animals were allocated to one of the two treatment groups based on the pre-treatment faecal egg counts (FEC). Animals were treated on Day 0 with an oral paste containing either IVM (at 0.2mg/kg bodyweight) or MOX (at 0.4 mg/kg bodyweight). After treatment, faecal samples were collected at least every fortnight during 56 days after treatment with IVM and during 84 days after MOX treatment. In total, 320 horses on 32 farms were examined. The FECRT on Day 14 indicated a 100% efficacy in 59 of the 64 treatment groups and >92% efficacy in the remaining 5 groups. The ERP was decreased for at least one of the anthelmintics on 17 out of 32 study sites (15 sites or 47% for MOX and 17 sites or 53% for IVM) and on 9 sites (28%) the ERP was decreased for both anthelmintics. On some of these study sites the efficacy declined at the end of the expected ERP, often with good efficacy 2 weeks earlier. Nevertheless, on 1, 3 and 5 study sites in Italy, Belgium and The Netherlands respectively, an efficacy below 90% for IVM and MOX was identified as soon as Day 42 or Day 56. In The Netherlands, the efficacy of IVM was below 90% from Day 28 or Day 35 after treatment on 1 site each. The present study reports a high efficacy of MOX and IVM in a FECRT 14 days after treatment, yet does indicate a shortened ERP for these treatments in more than half of the selected study sites.

Anthelmintic resistance in cyathostomin populations from horse yards in Italy, United Kingdom and Germany.

BACKGROUND: A large survey was carried out in 2008 in Europe to evaluate the efficacy of fenbendazole (FBZ), pyrantel (PYR), ivermectin (IVM) and moxidectin (MOX), i.e. the major anthelmintic molecules used in current practice against cyathostomins affecting horses. A total of 102 yards and 1704 horses was studied in three countries: 60 yards and 988 horses from Italy, 22 and 396 from the UK, 20 and 320 from Germany. The survey consisted of Faecal Egg Count Reduction Tests (FECRTs) with a faecal egg count reduction (FECR) categorization of (I) resistance present if FECR <90% and the lower 95% confidence limit (LCL) <90%, (II) resistance suspected if FECR >/= 90% and/or LCL <90% and (III) no resistance if FECR >/= 90% and LCL >90%. The calculation of FECR data was performed employing bootstrap analysis of group arithmetic means. RESULTS: The testing of FBZ on a total of 80 yards resulted in resistance present on more than 80% of the UK and German yards and on significantly fewer in Italy, i.e. in 38% (p < 0.01). PYR, IVM and MOX were tested on a total of 102 yards. For PYR resistance present was found in 25% of the yards with no significant differences between countries. For IVM resistance present was encountered in one Italian and two UK yards (3%), resistance present to MOX was not found in any yard in any country. CONCLUSION: The results indicate that single and/or multiple drug resistance in equine cyathostomins is present in the three countries, is widespread particularly for FBZ and/or PYR and in one UK yard multiple resistance present was detected to FBZ, PYR and IVM. Macrocylic lactones proved to be the most effective drugs, with some evidence of resistance to IVM and highest activity of MOX, despite a single case of reduced efficacy in Germany. These data call for the development and implementation, among practitioners, owners and managers, of further plans to reduce the expansion of the anthelmintic resistant populations and to use those anthelmintics that remain effective in a manner that preserves their efficacy as long as possible.

Effects of worm control practices examined by a combined faecal egg count and questionnaire survey on horse farms in Germany, Italy and the UK.

BACKGROUND: For the control of worm infections, the strategic use of anthelmintics, often accompanied by additional farm and/or pasture management procedures, is currently applied on most horse farms in industrialized countries. However, the particular effects of the specific worm control procedures are often unclear and have only been investigated to a limited extent. We examined faecal egg count (FEC), faecal egg count reduction (FECR) and questionnaire data on farm and pasture management procedures. The aim of this study was to determine whether specific worm control practices reported to be applied in European horse farms affect worm prevalence. RESULTS: This study involved 20 German, 26 Italian and 16 UK horse farms for each of which FEC were performed on a minimum of 16 horses. In total, 2029 horse faecal samples were quantitatively analysed for helminth eggs, resulting in 56.3% of the faecal samples being positive for strongylid eggs. The prevalence in the 742 German horse samples (48.1%) was significantly lower than that in the 737 Italian (61.1%) and the 550 UK (60.9%) samples. As expected, a significant effect of horse age on the infection prevalence was observed, with adult horses showing lower prevalences and lower mean FEC than foals and yearlings. The majority of the participating farms were stud farms (n = 29), followed by riding stables (n = 27) and racehorse stables (n = 6). The prevalence of strongyle infection by farm type differed between countries. While in Germany, horses on riding farms were significantly less often strongyle positive, in the UK horses on stud farms showed the lowest strongyle prevalences, whereas in Italy, no significant difference between farm types were seen. On all farms, horses received routine/preventive anthelmintic treatment. An effect of treatment frequency on strongyle prevalence was only encountered with adult horses. On farms performing more than one annual treatment, faecal samples were significantly less often positive. Furthermore, by comparing the FECR results of individual horses with their pre-treatment FEC, it was found that high pre-treatment FEC were associated with a significantly higher probability for a FECR below 90%. CONCLUSION: Overall, age-dependent strongyle infection patterns and general worm control approaches were found to be similar on horse farms in the three countries. Also, a negative association of pre-treatment FEC and treatment efficacy was consistently found in all countries. However, mean strongyle prevalences and frequencies of anthelmintic treatments were considerably different. In addition to the age-dependent prevalence patterns, the finding of a possible negative association between high FEC and reduced FECR might argue for a focus on horses showing high pre-treatment FEC when monitoring anthelmintic treatment efficacy in the field.

Faecal Cyathostomin Egg Count distribution and efficacy of anthelmintics against cyathostomins in Italy: a matter of geography?

BACKGROUND: In the framework of a trial carried out in 2008 in Europe to evaluate the efficacy of major parasiticides against horse cyathostomins, pre- and/or post-treatment Faecal Egg Counts (FEC) were evaluated in a total of 84 yards and 2105 horses from nine different regions from the South, the Center, the North-Center and North-East of Italy. Specifically, on the basis of FECs of the horses present in each property, 60 out of the 84 yards were enrolled for a Faecal Egg Count Reduction Test (FECRT) using fenbendazole, pyrantel, ivermectin and moxidectin. RESULTS: Of the 1646 horses bred in the 60 recruited yards, 416 animals had a FEC between 50 and 150 Eggs Per Gram (EPG) of faeces and 694 a FEC >150 EPG (i.e. with total of 1110 positive animals). Of the 1110 positive animals, those with the highest FECs (i.e. 988) were included in the FECRT. The FECRT for four anthelmintic compounds showed remarkable differences in terms of prevalence of reduced and equivocal efficacy against cyathostomins in the different areas of Italy. Administration of fenbendazole and pyrantel resulted in resistance present or suspected in about half of the yards examined while resistance to ivermectin was found in one yard from central Italy and suspected resistance was detected in three more yards, one in each the North, the Center and the South. Treatment with moxidectin was 100% effective in all yards examined. CONCLUSION: Cyathostomin populations in the South and the Center of Italy were more susceptible to fenbendazole and pyrantel than the populations present in the Center-North and North-Eastern areas of Italy. Fenbendazole and/or pyrantel were ineffective in almost all properties from the North of Italy. The reasons for such a difference among the Italian regions in terms of FECs and efficacy of antiparasitic drugs are discussed, together with the role that veterinarians, and horse owners and managers should have for effective worm control programs in this country.

Sero-epidemiological survey of Neospora caninum infection in dogs in north-eastern Italy.

Risk factors associated with Neospora caninum seroprevalence in north-eastern Italy in healthy dogs were assessed. Antibodies to N. caninum were found in 10.9% of 707 kennel and owned dogs by a commercial competitive ELISA (VMRD Inc.). All dogs were negative for Leishmania infantum by indirect fluorescent antibody test indicating no cross reactivity or association between the two protozoa in this area. Seroprevalence association with breed and age of dogs and other factors are discussed.