Due to the high prevalence of gastrointestinal nematodes in sheep, the growing anthelmintic resistance, and the development of organic farming systems, sustainable alternatives are being sought. One such method is phytotherapy. This study aimed to evaluate the in vitro ovicidal and larvicidal activity of extracts of tansy (Tanacetum vulgare L.) growing in Latvia on gastrointestinal nematodes (Trichostrongylidae) in sheep. The leaves and flowers of the tansy were extracted separately in 70%, 50%, and 30% ethanol and acetone. Six concentrations were prepared from each extract 500 mg/mL, 200 mg/mL, 100 mg/mL, 50 mg/mL, 20 mg/mL, and 10 mg/mL. In vitro egg hatching test and micro-agar larval development test were performed. Extracts of tansy have strong larvicidal activity. The highest percentage of larvae inhibition for most of the extracts was 100%, but for egg inhibition, it was 95.8% for the 200 mg/mL concentration of 50% acetone and 93.3% for the 500 mg/mL concentration of 50% ethanol leaf extracts. All tansy extracts had ovicidal and larvicidal activity against Trichostrongylidae in sheep.

C. burnetii is a widespread pathogen, causing abortions and reproductive disorders in ruminants. The study aimed to evaluate animal reproductive capacity and productivity after abortion, related and unrelated to C. burnetii. We compared data about the abortion time, the outcome of the animals after an abortion, further reproduction, and productivity for C. burnetii-positive (n = 148) and C. burnetii-negative (n = 149) aborted dairy cows and heifers. C. burnetii-positive animals had a positive serological response or presence of C. burnetii DNA at the time of abortion. C. burnetii-positive animals had a significantly higher number of lactations at the time of abortion. However, in the other indicators, we observed no significant differences between the groups. Comparing indicators of all the aborted animals, we found that if animals started a new lactation after abortion, they had a significantly lower milk yield, lower fat, protein, and somatic cell counts (SCCs) in milk during the standard lactation for both primiparous and multiparous cows compared to herd averages in each group. Lower SCCs can be due to animals with a high SCC being culled earlier. We found an economic disadvantage to aborting, not only because of the loss of offspring, but also because of the high culling rate and lower productivity in both primiparous and multiparous cows.

Antimicrobial resistance (AMR) in food-producing animals is a growing One Health concern. However, data on AMR in indicator microorganisms from clinically healthy dairy cattle in Latvia remain limited. This study aimed to characterize the AMR profiles of Escherichia coli and Enterococcus spp. isolated from rectal swabs and bulk-tank milk collected from 18 dairy farms between February and May 2025. Bacterial identification was performed using conventional culturing and MALDI-TOF mass spectrometry, and antimicrobial susceptibility was determined using the disk diffusion (Kirby–Bauer) method, interpreted according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Resistance levels were further quantified using resistance scores (R-scores) and the Multiple Antibiotic Resistance Index (MARI). In total, 582 E. coli and 428 Enterococcus spp. isolates were recovered from rectal swabs, with E. coli showing the highest resistance to ampicillin (12.5%) and amoxicillin–clavulanic acid (6.7%), whereas resistance to tetracycline was rare (0.3%). Enterobacteriaceae from milk exhibited higher resistance to ampicillin (45.8%) and amoxicillin–clavulanic acid (20.8%). Among Enterococcus spp., resistance was highest to an antibiotic not used in dairy cows in Latvia quinupristin–dalfopristin (69.2%), while resistance to vancomycin and linezolid remained low (0.5% each). Milk-derived enterococci showed a comparable pattern, with additional resistance to streptomycin (25%). Overall, resistance levels and multidrug resistance were low. However, the presence of sporadic resistant isolates and elevated MARI values, particularly in large-scale farms and milk-derived bacteria, highlights the importance of continued AMR surveillance and prudent antimicrobial use in the Latvian dairy sector.

Background and Aim: Gastrointestinal nematode infections have a significant impact on the health and productivity of sheep worldwide. Conventional anthelmintics are facing rising resistance, prompting the need for alternative control strategies. Tanacetum vulgare (tansy), a traditionally used antiparasitic herb in Latvia, has shown in vitro efficacy but lacks in vivo delivery validation. This study aimed to evaluate the in vivo antiparasitic efficacy and safety of T. vulgare extract administered through novel intraruminal boluses and granules in naturally infected sheep. Materials and Methods: Thirty female Latvian Darkhead lambs (4–5 months; mean 35 ± 0.8 kg) were randomly assigned to five groups: Two bolus groups (A and B), one granule group, and two controls (negative and positive). Groups A and B received intraruminal boluses with different lyophilized extract formulations, the granule group received powdered T. vulgare mixed with feed, and the positive control received levamisole. Fecal egg counts (FECs), clinical signs, and hematological and biochemical parameters were assessed over 56 days. Disintegration testing simulated rumen conditions. Results: No adverse clinical or physiological effects were observed. Bolus groups exhibited a more rapid and consistent reduction in strongylid FECs compared to the granule and negative control groups. On day 56, egg counts decreased to 325–358 eggs per gram (EPG) in bolus and granule groups, compared to 533 EPG in the negative control. Hematological and biochemical parameters remained within reference ranges. Conclusion: T. vulgare extract administered through intraruminal bolus was safe, sustained animal health, and effectively reduced gastrointestinal nematode burden. Granules were less effective, potentially due to reduced palatability. Bolus-based phytotherapy may serve as a sustainable, prophylactic alternative to conventional anthelmintics. Keywords: fecal egg count, gastrointestinal nematodes, intraruminal bolus, phytotherapy, sheep, Tanacetum vulgare.