Anthelmintic overuse and failure to implement methods preventing the development and spread of anthelmintic resistance (AR) have led to an alarming increase of resistant ovine trichostrongylids worldwide. The aim of the present study was to determine whether the routine anthelmintic treatment strategy was effective, to obtain insights into the frequency of AR in trichostrongylids of sheep in Austria, and to determine the presence of different trichostrongylid genera. On 30 sheep farms, the faecal egg count reduction test (FECRT) was performed with the Mini-FLOTAC technique in two consecutive studies. In study 1, only fenbendazole and moxidectin were tested, while different compounds and products were used in study 2. Overall, 33 treatment groups were formed: 11 groups were treated with benzimidazoles (fenbendazole and albendazole), 2 groups with avermectins (ivermectin, doramectin), 18 groups with moxidectin, and two groups with monepantel. Reduced efficacy was detected in 64%, 100%, 28% and 50% of these groups, respectively. The most frequently detected genus in larval cultures was Haemonchus, which had been barely detected in Austria previously, followed by Trichostrongylus. Multispecific resistance of trichostrongylids in Austria seems to be on the rise and H. contortus was detected unexpectedly frequently in comparison to previous studies. There is an urgent need to develop efficient communication strategies aimed at improving the engagement of farmers and veterinarians in sustainable parasite control.

Rumen flukes have received growing veterinary attention in western and central Europe during the past two decades because of an increase in prevalence of infection in cattle and sheep, including cases of severe clinical disease. Historically, rumen fluke infections in Europe were assumed to be caused mainly by Paramphistomum cervi (or species, which were later considered to be synonymous with P. cervi), but more recently molecular studies demonstrated Calicophoron daubneyi to be the predominating species. For the present investigation, adult rumen flukes isolated from 23 cattle originating from ten farms in Germany (Saxony [1], Baden-Württemberg [4], Bavaria [5]) and one farm in Austria (Tyrol) were analyzed to establish partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI) and the complete sequence of the nuclear internal transcribed spacer 2 (ITS2). Flukes of five animals (dairy cows from three farms in Bavaria) were determined as P. leydeni, and flukes of 18 animals (dairy cows or cattle from cow-calf operations from eight farms in Saxony [1], Baden-Württemberg [4], Bavaria [2], and Tyrol [1]) were identified as C. daubneyi. Based on the molecular analysis of adult rumen flukes collected from cattle, the results of this investigation confirm the common occurrence of C. daubneyi in Germany and reveal the first definitive findings of P. leydeni in Germany and C. daubneyi in Austria.

Anthelmintic resistance (AR) of trichostrongyloids is widespread in Europe, but there is no up-to-date information on the spread of AR in caprine parasites in Austria. Eprinomectin (EPR) is currently the only anthelmintic drug of the macrocyclic lactones registered for goats in Europe. The aim of the present study was to gather information regarding the efficacy of anthelmintics against trichostrongyloids on a dairy goat farm in Austria with reported treatment failure of macrocyclic lactones and to determine the presence of different trichostrongyloid genera. Faecal egg count reduction tests (FECRT) using Mini-FLOTAC were performed with eprinomectin (EPR) and moxidectin (MOX). Egg count reduction, calculated with the R package egg-Counts, was 44% for EPR and 86% for MOX, confirming AR of trichostrongyloids for both compounds. The most frequently detected genus in larval cultures was Haemonchus, followed by Trichostrongylus. This is the first report of MOX resistance in caprine trichostrongyloids in Europe. Failure of EPR and MOX to control trichostrongyloid infections is a severe threat to dairy goat farming, since other compounds must not be applied in goats used for milk production. Haemonchus contortus is one of the most pathogenic parasites of small ruminants and can quickly develop AR. Thus, immediate action should be taken to slow the further spread of AR in this and other roundworm species of ruminants in Austria.

No abstract

Enterocytozoon bieneusi is an obligate intracellular pathogen that infects livestock, companion animals, and wildlife and has the potential to cause severe diarrhea especially in immunocompromised humans. In the underlying study, fecal samples from 177 calves with diarrhea and 174 adult cows originating from 70 and 18 farms, respectively, in Austria were examined for the presence of E. bieneusi by polymerase chain reaction targeting the Internal Transcribed Spacer 1 (ITS1) region. All positive samples were further sequenced for genotype determination. Overall, sixteen of the 351 (4.6%) samples were positive for E. bieneusi, two of the 174 samples from cows (1.2%) and 14 of the 177 samples from calves (7.9%). In total, four genotypes, J (n = 2), I (n = 12), BEB4 (n = 3), and BEB8 (n = 1), were identified. The uncorrected p-distance between the four ITS1 lineages (344 bp) ranges from 0.3% to 2.9%. The lineages differ by 1 bp (I and J), 2 bp (J and BEB4), and 3 bp (I and BEB4), respectively, and BEB8 differs by 7 to 10 bp from the latter three lineages. Two of the E. bieneusi-positive calves showed an infection with two different genotypes. E. bieneusi occurred significantly more often in calves > 3 weeks (8/59) than in calves ≤ 3 weeks (6/118), respectively (p = 0.049). Calves with a known history of antimicrobial treatment (50 of 177 calves) shed E. bieneusi significantly more often than untreated calves (p = 0.012). There was no statistically significant difference in E. bieneusi shedding in calves with or without a medical history of antiparasitic treatment (p = 0.881). Calves showing a co-infection with Eimeria spp. shed E. bieneusi significantly more often than uninfected calves (p = 0.003). To our knowledge, this is the first report of E. bieneusi in cattle in Austria. Cattle should be considered as a reservoir for human infection since potentially zoonotic E. bieneusi genotypes were detected.