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.

Numerous treatment agents offering prophylaxis against livestock parasites are commercially available. However, because of increasing antiparasitic drug resistance, the increased popularity of environmentally friendly lifestyle choices, and organic farming, there is more demand for new alternatives to livestock anthelmintic control strategies and medications. It is important to develop antiparasitics that are safe, effective, inexpensive, and environmentally safe. Local, traditional herbal plants such as tansy, mugwort, wormwood, and heather may serve as treatments for intestinal parasites of sheep. This overview provides knowledge of traditional Latvian plants with antiparasitic activities to establish a database for further research to develop new herbal antiparasitic drugs.

Background and Aim: There is little understanding about antiparasitic drug prescription trends and implementation to reduce possible drug overuse or misuse worldwide. This study aimed to review sheep parasite control strategies and antiparasitic drug use habits in Latvia. To the best of the author's knowledge, this is the first study in the world that describes how antiparasitic drugs are used and what are the most common drug usage errors in a sheep farm. Materials and Methods: A semi-structured questionnaire was designed to collect relevant information from face-to-face interviews to assess 22 sheep farmers' knowledge and management procedures in farms. We collected information about animal feeding, herding, parasite diagnostics, and antiparasitic drug usage. The questionnaire summary included information on pasture use, parasite control management, and anthelmintic drug choice/use. Results: Only 36% of farms regularly managed parasite control by analyzing fecal samples for parasites, but prophylactic deworming was employed in all farms. Ivermectin, albendazole, levamisole, and monepantel were used on the farms and most of the farms were multidrug users; 77.3% of the farms used albendazole and 72.7% used ivermectin. Conclusion: The results indicated a lack of parasitological examination and parasite control of the flock, mostly empiric drug selection, incorrect dosing, inaccurate drug administration, drug storage, and use errors. A proactive approach to herd health planning, regular parasitic control, and prophylactic measures may benefit farmers and veterinarians.

Background and Aim: Parasitic invasions, especially gastrointestinal nematodes, are widespread and are one of the main problems in sheep farms. For this reason, sheep are dewormed more often than other livestock species, often several times a year. Concerns about antiparasitic resistance from the farmers and veterinarians have arisen because, on some farms, antiparasitic drugs are used routinely for very long periods. There are no data available on anthelmintic resistance in gastrointestinal nematodes in sheep in Latvia. Our work aimed to determine the most common endoparasites in sheep and the degree of anthelmintic resistance on sheep farms in Latvia. Materials and Methods: All sheep (577) underwent a coprological examination before the start of the study, and only sheep diagnosed with more than 200 McMaster eggs per gram of feces were included in the study. A fecal egg count reduction (FECR) test was performed on 20 sheep flocks in Latvia. Results: In Latvia, sheep were most commonly infected with Eimeria spp. 97% (confidence interval [CI] 95% 96-98). The second most commonly diagnosed species were Trichostrongylidae 91% (CI 95% 89-93) and Strongyloides spp. 76% (CI 95%, 72-79). The ivermectin (IVM) FECR was 0.74% (0.73-0.74), showing resistance in all sheep farms included in this study. Albendazole (ABZ) FECR 0.89% (0.88-0.89) was effective. Conclusion: This study showed that the most popular deworming drugs (ivermectin, albendazole) in Latvia are ineffective in sheep. Additional studies on the use of IVM+ABZ combinations for deworming sheep should be performed.

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.

Liver flukes may cause significant pathological changes in domestic and wild ruminants. One such parasite, Parafasciolopsis fasciolaemorpha , reported in European moose ( Alces alces ), still requires detailed investigation to better understand its pathogenesis and impact on host health. This study aimed to evaluate the gross, histopathological, and biochemical alterations associated with natural P. fasciolaemorpha infection in wild moose inhabiting forests throughout Latvia. Livers from 63 animals were examined, of which 15 (24%) were infected. Infected livers exhibited bile duct thickening and cavities containing trematodes and necrotic debris. Histologically, lesions in infected moose were observed in 82% of examined microscopic fields for portal inflammatory infiltration, 60% for portal fibrosis, and 47% for bile duct proliferation, compared with low frequencies in uninfected animals. Generalized linear mixed models confirmed significant associations between infection and portal inflammation, fibrosis, and bile duct proliferation, whereas bile duct mucous gland hyperplasia did not differ significantly from uninfected moose. Biochemically, infected moose showed reduced serum urea and amylase concentrations, while other hepatic enzyme values did not differ from uninfected controls, indicating mild impairment of hepatic function and possible pancreatic involvement. Fecal examination confirmed the presence of P. fasciolaemorpha eggs and revealed frequent co‐infections with gastrointestinal parasites. These findings demonstrate that P. fasciolaemorpha infection in moose is associated with distinctive hepatic lesions and subtle but measurable biochemical alterations, expanding knowledge of this understudied trematode and emphasizing its importance in veterinary pathology and wildlife health.