Barbara Hinney

Fasciola hepatica impairs animal health and productivity in ruminants and has been associated with Salmonella Dublin infection, a zoonotic pathogen in cattle that causes diarrhea, abortions, and pneumonia. This work reassessed F. hepatica seroprevalence in Tyrolean dairy herds and investigated associations with alpine pasturing, the breed, S. Dublin occurrence and milk performance. In late autumn/early winter 2023, bulk tank milk samples from 3645 farms were tested using a commercial ELISA test (IDEXX Fasciolosis Verification Test, Montpellier, France). Binary logistic regression and linear mixed models were used to evaluate risk factors and production effects. Overall, 86.1% of herds were positive for Fasciola antibodies - an increase of 13.1% compared to 2005. Alpine pasturing was a significant risk factor (odds ratio [OR] 4.7), and S. Dublin-positive farms had higher odds of Fasciola -infection (OR = 9.0). In non-alpine grazing herds, all models showed that Fasciola -infection was significantly associated with reduced milk yield, while no such associations were observed in the population with alpine pasture management. However, breed-specific analysis among alpine-pastured cows showed significant negative associations on milk yield in Simmental ( p = 0.041) and Brown Swiss ( p = 0.039). These results reveal an increasing F. hepatica prevalence in Tyrol and highlight alpine pasturing as a major risk factor. The observed production losses and the strong link with S. Dublin emphasize the parasite`s broader economic and public health importance for dairy farms in the European Alps. From a practical perspective, there is a clear need for region-specific F. hepatica control strategies in alpine dairy systems, with particular focus on pasture management and herd-level surveillance.

Background: Pasture-based management of dairy cattle in temperate regions leads to infections with gastrointestinal nematodes, with Ostertagia ostertagi recognised as the most pathogenic species of these. However, little is known about O. ostertagi exposure in alpine regions. Here, we aimed to explore the O. ostertagi seropositivity in a large sample of dairy cows from two Austrian federal states that differ substantially in herd size, productivity and use of (alpine) pastures, and to assess associations between parasite exposure, milk yield, and farm management factors. Methods: Bulk tank milk (BTM) samples from 1241 dairy farms in the federal states of Upper Austria ( n = 742) and Tyrol ( n = 499), of which the dairy herds comprised a total of 25,985 adult cows, were analysed for anti- O. ostertagi immunoglobulin G at the end of the grazing season 2018. Anti- Ostertagia antibody levels in milk [measured as the optical density (OD) ratio (ODR)] from herds with known grazing were evaluated for associations with production and management data via linear models to (1) evaluate the effect of farm management practices on herd exposure to O. ostertagi , and (2) assess the association of O. ostertagi exposure and management practices with milk production. Results: Of all the investigated herds, 65.3% were positive for O. ostertagi infections (ODR ≥ 0.5), with a mean ODR of 0.59 (25th–75th percentile 0.42–0.75). Herds in Tyrol had higher mean BTM-ODR values (0.73; 25th–75th percentile 0.61–0.87) than those in Upper Austria (0.50; 0.38–0.63); however, alpine grazing was not associated with higher ODR values in either Austrian state. In Upper Austria, organic farming was significantly associated with higher O. ostertagi exposure, whereas in Tyrol, larger herd sizes were linked to increased exposure. Lower milk yield was significantly associated with decreasing cow herd size and organic farming in both federal states, but not with increasing O. ostertagi ODR. Conclusions: Marked differences in the exposure of Austrian dairy cattle to O. ostertagi are likely explained by contrasting grazing management between the investigated states and by specific characteristics of each region. No association between increased parasite exposure and milk yield was observed, highlighting the need for region-specific investigations. Small-scale and/or alpine cattle farming with predominantly dual-purpose breeds requires a tailored risk assessment to support sustainable parasite control strategies. Graphical

Haemonchus contortus is considered the most pathogenic nematode in small ruminants and South American camelids, causing significant production losses and threatening animal welfare worldwide. Compared to the use of anthelmintic drugs, to which resistance is increasing, vaccination is considered a more sustainable control strategy. The safety and efficacy of a novel glycoengineered vaccine produced in Hi5 insect cells was evaluated in a randomized, controlled vaccination-and-challenge trial. For this, 35 male Jura x Lacaune sheep were assigned to five groups (n=7). Three experimental groups were vaccinated three times subcutaneously with 1 ml of either the commercial Barbervax ^® vaccine, the novel glycoengineered vaccine, consisting of a cocktail of five antigens (H11, H11-1, H11-2, H11-4 and GA1), or its non-glycoengineered counterpart before challenge with 5,000 H. contortus third-stage larvae. Clinical assessments, differential blood counts, serum antibody responses and fecal egg counts were evaluated at least once per week within the 16-week trial period. The abomasal worm burden was counted 40 days after challenge. The results of the mixed model showed a lower degree of anemia (mean packed cell volume (PCV) of 26.77%; mean hemoglobin (Hb) of 9.03 g/dl), in sheep vaccinated with the glycoengineered antigen cocktail compared to the unvaccinated group (PCV of 24.34%; mean Hb of 7.84 g/dl) and to the sheep vaccinated with the non-glycoengineered antigens (PCV of 26.11%; mean Hb of 8.53 g/dl). However, the degree of anemia was lower in sheep vaccinated with native antigens (Barbervax ^® ) (PCV of 29.10%; mean Hb of 9.84 g/dl). Serum IgG and IgE antibodies were elevated in all vaccinated groups. Sheep vaccinated with the glycoengineered antigens showed a reduction in abomasal worm burden of 25.36% and a reduction of fecal egg shedding of 81.09%, the group vaccinated with non-glycoengineered antigen showed no worm reduction and a fecal egg count reduction of 32.72%. While there was no significant difference in egg shedding between sheep vaccinated with the glycoengineered antigens and sheep vaccinated with Barbervax ^® (98.32%; p = 0.33), the Barbervax ^® group showed a greater reduction in worm burden (86.40%). The results emphasize that glycoengineering of vaccine candidates is essential to achieve protective immunity against H. contortus in sheep and that the novel glycoengineered vaccine produced in insect cells clearly has the potential to reduce fecal egg shedding and worm burden, paving the way for the development of highly effective recombinant vaccines against this and other parasitic worms in the future.

The population of South American camelids (SAC) has been steadily growing in Europe, where they are confronted with the regional endoparasite population of ruminants. As there are no anthelmintic drugs registered for use against nematode infections in SACs, anthelmintics (AH) available for ruminants or horses are usually applied. Reports indicating potential failures in administered AH are increasing. However, the generally low egg counts in SACs complicate the application of resistance tests in the field. The present study reports a follow-up study on SAC farms where anthelmintic resistance (AR) was suspected. The aims were (i) to repeat faecal egg count reduction tests (FECRTs) on potentially affected farms identified in a previous study with larger sample sizes, (ii) to verify suspected AR of Haemonchus contortus against benzimidazoles (BZ) by performing a single-nucleotide polymorphism (SNP) analysis using digital polymerase chain reaction (dPCR), and (iii) to apply the mini-FLOTAC technique for more reliable results at low egg counts in line with current recommendations. Seven farms (9–46 animals each) were examined by coproscopy, larval differentiation and SNP analysis. A FECRT was performed on six of these farms with moxidectin (three farms), monepantel (two farms) and ivermectin (one farm). The FEC was calculated according to the current World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines with the clinical protocol (a newly introduced variant of FECRT which can be used for smaller sample sizes and lower egg counts on the cost of sensitivity) and an expected efficacy of 99%. A high level (> 90%) of BZ-resistance-associated SNPs on codon 200 of H. contortus was observed on all farms. With the FECRT, resistance was demonstrated for ivermectin (74% FECR), while it remained inconclusive for one farm for moxidectin treatment. Sustained efficacy was demonstrated for the remaining treatments. This study showed an advanced level of BZ resistance in H. contortus of SACs and the development of AR against macrocyclic lactones on some farms. Thus, constant monitoring of AH treatment and sustainable worm control methods both need to be applied. Graphical Abstract

Gastrointestinal nematodes, most notably trichostrongylids, are known to cause significant losses in sheep production. Previous studies have shown that monitoring parameters (e.g., FAMACHA©, BCS, dag score) change with increasing egg excretion. These parameters are well known and frequently used for targeted selective treatment. Based on the willingness to participate in this study (based on a previous questionnaire distribution among sheep farmers in Austria) we investigated the associations between faecal egg counts and the FAMACHA©, BCS, and dag scores of 1195 dairy ewes. Faecal samples were analysed using the Mini-FLOTAC technique I and larval culture. Three raters assessed the FAMACHA©, BCS, and dag scores in sheep to calculate the inter-rater agreement and intraclass correlation coefficient. The responses to the questionnaire of 23 farms were used for the evaluation, of which 16 farms were visited. Trichostrongylid eggs were detected in 95% of the faecal samples. The BCS was negatively correlated with the eggs per gram of faeces (EpG) (r = −0.156; p < 0.001) and the FAMACHA© score was slightly positively correlated with EpG (r = 0.196; p < 0.001). A small proportion of sheep (25%) shed the majority of eggs (47% to 84%). A moderate to good agreement for the parameters was found between the raters. In conclusion, the clinical parameters showed only weak correlations with faecal egg counts, and we confirmed that a minority of the flock is responsible for the majority of the pasture contamination with trichostrongylid eggs. Clinical raters should be trained before a study to increase the agreement between them.

Acute abdominal pain (colic) is one of the major equine health threats worldwide and often necessitates intensive veterinary medical care and surgical intervention. Equine coronavirus (ECoV) infections can cause colic in horses but are rarely considered as a differential diagnosis. To determine the frequency of otherwise undetected ECoV infections in horses with acute colic, fresh fecal samples of 105 horses with acute colic and 36 healthy control horses were screened for viruses belonging to the Betacoronavirus 1 species by RT-PCR as well as for gastrointestinal helminths and bacteria commonly associated with colic. Horses with colic excreted significantly fewer strongyle eggs than horses without colic. The prevalence of anaerobic, spore-forming, gram-positive bacteria (Clostridium perfringens and Clostridioides difficile) was significantly higher in the feces of horses with colic. Six horses with colic (5.7%) and one horse from the control group (2.8%) tested positive for Betacoronaviruses. Coronavirus-positive samples were sequenced to classify the virus by molecular phylogeny (N gene). Interestingly, in three out of six coronavirus-positive horses with colic, sequences closely related to bovine coronaviruses (BCoV) were found. The pathogenic potential of BCoV in horses remains unclear and warrants further investigation.