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Helminth infections are ubiquitous in grazing ruminant production systems, and are responsible for significant costs and production losses. Anthelmintic Resistance (AR) in parasites is now widespread throughout Europe, although there are still gaps in our knowledge in some regions and countries. AR is a major threat to the sustainability of modern ruminant livestock production, resulting in reduced productivity, compromised animal health and welfare, and increased greenhouse gas emissions through increased parasitism and farm inputs. A better understanding of the extent of AR in Europe is needed to develop and advocate more sustainable parasite control approaches. A database of European published and unpublished AR research on gastrointestinal nematodes (GIN) and liver fluke (Fasciola hepatica) was collated by members of the European COST Action “COMBAR” (Combatting Anthelmintic Resistance in Ruminants), and combined with data from a previous systematic review of AR in GIN. A total of 197 publications on AR in GIN were available for analysis, representing 535 studies in 22 countries and spanning the period 1980–2020. Reports of AR were present throughout the European continent and some reports indicated high within-country prevalence. Heuristic sample size-weighted estimates of European AR prevalence over the whole study period, stratified by anthelmintic class, varied between 0 and 48%. Estimated regional (country) prevalence was highly heterogeneous, ranging between 0% and 100% depending on livestock sector and anthelmintic class, and generally increased with increasing research effort in a country. In the few countries with adequate longitudinal data, there was a tendency towards increasing AR over time for all anthelmintic classes in GIN: aggregated results in sheep and goats since 2010 reveal an average prevalence of resistance to benzimidazoles (BZ) of 86%, macrocyclic lactones except moxidectin (ML) 52%, levamisole (LEV) 48%, and moxidectin (MOX) 21%. All major GIN genera survived treatment in various studies. In cattle, prevalence of AR varied between anthelmintic classes from 0–100% (BZ and ML), 0–17% (LEV) and 0–73% (MOX), and both Cooperia and Ostertagia survived treatment. Suspected AR in F. hepatica was reported in 21 studies spanning 6 countries. For GIN and particularly F. hepatica, there was a bias towards preferential sampling of individual farms with suspected AR, and research effort was biased towards Western Europe and particularly the United Kingdom. Ongoing capture of future results in the live database, efforts to avoid bias in farm recruitment, more accurate tests for AR, and stronger appreciation of the importance of AR among the agricultural industry and policy makers, will support more sophisticated analyses of factors contributing to AR and effective strategies to slow its spread.

Simple Summary: Untreated and stray dogs and cats, in particular, play an important role in contaminating the environment with important zoonotic parasites. Archive faecal samples collected between 2016–2019 from dogs (n = 789) and cats (n = 241) were examined using the IDEXX Fecal DxTM and SNAPTM Giardia antigen assays for the detection of Toxocara, hookworms, Trichuris and Giardia infections. Giardia duodenalis was the most common parasite (26%) detected in the dogs, followed by ascarids (17.6%) and hookworms (5.3%). Trichuris vulpis was only detected in 1 dog. Ascarids (23.2%) was the most common parasite detected in the cats, followed by Giardia (12.9%) and hookworms (2.9%). This study shows a high prevalence of parasite infection in untreated and stray dogs and cats in the greater Dublin area in Ireland. Since they live in synanthropic conditions and can roam over vast distances, they can contaminate public areas and pose a risk to both humans and owned pets that utilise these spaces. It is therefore important to raise public awareness and increase the knowledge on zoonotic parasites. Endoparasites of dogs and cats, play an important role in both veterinary medicine and public health. Untreated and stray dogs and cats, in particular, play an important role in contaminating the environment with important zoonotic parasites. Thus, the aim of this study was to estimate the prevalence of intestinal parasites in stray dogs and cats using highly sensitive and specific copro-antigen tests. Archive faecal samples from previous surveys conducted between 2016–2019 from dogs (n = 789) and cats (n = 241) were included in this study. The IDEXX Fecal Dx™ antigen panel was used for the detection of Toxocara, hookworms, Trichuris and the SNAP™ Giardia antigen assay was used for the detection of Giardia infection. Giardia duodenalis was the most common parasite (26%, n = 205) detected in the dogs, followed by ascarids (17.6%, n = 139) and hookworms (5.3%, n = 42). Trichuris vulpis was only detected in 1 dog. Ascarids (23.2%, n = 56) was the most common parasite detected in the cats, followed by Giardia (12.9%, n = 31) and hookworms (n = 7, 2.9%). No whipworms were detected in cats. Overall, there was little difference in the positivity between sexes in both dogs and cats. However, in terms of age, adolescent dogs (<3 years) and kittens (<1 year) had the highest parasite prevalence overall, with G. duodenalis and ascarids being the most prevalent. This study shows a high prevalence of parasite infection in untreated and stray dogs and cats in the greater Dublin area in Ireland. Since they live in synanthropic conditions and can roam over vast distances they can contaminate public areas and pose a risk to both humans and owned pets that utilise these spaces. It is therefore important to raise public awareness and increase the knowledge on zoonotic parasites. [ABSTRACT FROM AUTHOR]

Abstract Cryptosporidiosis, a protozoal disease which causes significant morbidity in humans, is one of the chief causes of diarrhoea in neonatal ruminants. although the parasite poses a significant threat to public health and animal health in Ireland, its epidemiology on the island is only poorly understood. Environmental studies have shown the waterborne parasite to be widespread in some untreated waterbodies around Ireland. The island's hydrogeological situation, combined with high stocking rates of livestock and the absence of filtration from regular water treatment, render it vulnerable to large-scale outbreaks. This review discusses the parasite in the Irish context and underlines the need for a reference facility to provide active surveillance on the island.

Abstract Cryptosporidiosis, a protozoal disease which causes significant morbidity in humans, is one of the chief causes of diarrhoea in neonatal ruminants. Although the parasite poses a significant threat to public health and animal health in Ireland, its epidemiology on the island is only poorly understood. Environmental studies have shown the waterborne parasite to be widespread in some untreated waterbodies around Ireland. The island's hydrogeological situation, combined with high stocking rates of livestock and the absence of filtration from regular water treatment, render it vulnerable to large-scale outbreaks. This review discusses the parasite in the Irish context and underlines the need for a reference facility to provide active surveillance on the island.

Background: The control of gastrointestinal nematodes (GIN) of cattle in pasture-based production systems such as Ireland is highly dependent on the availability of efficacious anthelmintics. There is very little information available on the efficacy of the broad-spectrum anthelmintics against GIN of cattle in Ireland and the aim of this study was to determine the prevalence of anthelmintic resistance on dairy calf to beef farms. Results: GIN burden was monitored on thirty-six recruited farms by performing herd level faecal egg counts (FEC) every 2 weeks. Of these, nine farms were lost from the study as calves were treated with an anthelmintic for Dictyocaulus viviparus, two were lost as they treated for GIN, one dropped out of the study and on one the herd FEC did not reach the threshold for carrying out the Faecal Egg Count Reduction Test (FECRT). On the remaining 23 farms, once the herd FEC reached 100 eggs per gram, a FECRT was carried out. Pre and post-treatment larval cultures were also performed to identify the GIN to genus level. The efficacy of fenbendazole, levamisole, ivermectin and moxidectin was evaluated on 15, 11, 16 and 11 farms respectively. Resistance to fenbendazole was identified on 9 farms (60%) with resistance suspected on a further farm. Resistance to levamisole, ivermectin and moxidectin was detected on 2 (18%), 16 (100%) and 8 (73%) farms respectively. The predominant genera detected pre and post-treatment were Cooperia and Ostertagia with both genera detected post-treatment with fenbendazole and ivermectin. Due to the low proportion of Ostertagia spp. pre-treatment, the efficacy of levamisole or moxidectin against this genus could not be reliably established. Conclusions: Anthelmintic resistance was widespread on the sampled dairy calf to beef farms in Ireland with resistance to benzimidazole, levamisole, ivermectin and moxidectin detected. [ABSTRACT FROM AUTHOR]

Abstract Gastrointestinal parasitism is a widely recognised problem in sheep production, particularly for lambs. While anthelmintics have a pivotal role in controlling the effects of parasites, there is a paucity of data on how farmers use anthelmintics. A representative sample of Irish lowland farmers were surveyed regarding their parasite control practices and risk factors that may contribute to the development of anthelmintic resistance. Questionnaires were distributed to 166 lowland Irish sheep producers. The vast majority of respondents treated their sheep with anthelmintics. Lambs were the cohort treated most frequently, the majority of farmers followed a set programme as opposed to treating at sign of disease. A substantial proportion (61%) administered four or more treatments to lambs in a 'normal' year. Departures from best practice in anthelmintic administration that would encourage the development of anthelmintic resistance were observed. In conclusion, in the light of anthelmintic resistance, there is a need for a greater awareness of the principles that underpin the sustainable use of anthelmintics and practices that preserve anthelmintic efficacy should be given a very high priority in the design of helminth control programmes on each farm. To this end, given that veterinary practitioners and agricultural advisors were considered to be the farmer's most popular information resource, the capacity of these professions to communicate information relating to best practice in parasite control should be targeted.

Abstract Blood samples were obtained from 38 wild red deer (Cervus elaphus) at two sites in Ireland and subjected to PCR analysis of the 18S rRNA gene followed by sequencing. Two fragments of the 18S rRNA gene were generated by two different PCR protocols and subsequent sequencing suggested that at least six of the deer were infected by a babesia that, in those loci, is indistinguishable from Babesia divergens, an important tick-borne pathogen of cattle and of zoonotic significance. Additionally, a B. odocoilei-like parasite was detected in three samples and a babesia that did not match any sequences in the GenBank database was found in five samples. Neither B. capreoli nor B. venatorum (EU1) were found. There have been several reports of B. divergens occurring in deer species, including red deer, roe deer (Capreolus capreolus) and reindeer (Rangifer tarandus). However, in view of recent re-sequencing of bovine-origin samples deposited previously in GenBank, it is unlikely that any of these sequences from deer are B. divergens. The present study describes the only deer piroplasm detected so far that shows complete identity with B. divergens, in just over half of the 18S rRNA gene. The entire gene of this deer parasite should be analysed and transmission experiments undertaken before the infectivity of B. divergens for red deer can be confirmed.

We report on the use of the faecal egg count reduction test to evaluate the performance of ivermectin in treating gastrointestinal nematode infections in first grazing season (FGS) calves on four dairy farms in Co. Kilkenny, Ireland. On each farm, FGS calves were injected subcutaneously with ivermectin in accordance with their live weight (day 0). Calves were individually faecal sampled on both day 0 and day 14. Faecal egg counts were determined using the Mini-FLOTAC technique. Composite faecal cultures for each farm were performed on each sampling occasion. The faecal egg count reductions (mode) ranged from 17.3–80.2% with the lower 95% confidence limit ranging from 3.1–72.3% on the four farms, respectively. Ivermectin-resistant nematodes were detected on all farms, with evidence of Ostertagia resistance on one farm. This study highlights the urgent need for Irish producers to reappraise their parasite control practices. [ABSTRACT FROM AUTHOR]