Veterinary parasitology最新文献

{"title":"The influence of the dung beetle Copris incertus on dung removal and gastrointestinal nematode density on pasture","authors":"Nicole L. Schon ,&nbsp;Tania S. Waghorn ,&nbsp;Derrick J. Wilson ,&nbsp;Alasdair Noble ,&nbsp;Dave M. Leathwick","doi":"10.1016/j.vetpar.2025.110500","DOIUrl":"10.1016/j.vetpar.2025.110500","url":null,"abstract":"<div><div>Gastrointestinal nematodes (GIN) are considered of major importance by livestock farmers, with burdens limiting production. Dung beetles have been reported to reduce GIN numbers by direct damage during ingestion, increasing aeration and desiccation in the dung pat, and moving dung deeper into the soil. This study investigates the impact of differing densities of the paracoprid dung beetle, <em>Copris incertus,</em> on GIN across different seasons in New Zealand. Treatments of different dung beetle abundances (Control, Low, Medium and High) were applied in field enclosures during four-week periods in spring, summer and autumn. A Natural treatment, with no enclosure to allow unrestricted colonisation of the dung, was included in summer and autumn. Dung pats containing nematode eggs were applied to all plots. In both spring and autumn there was increased dung removal at the highest dung beetle abundances. In spring the increased removal of dung from the soil surface was associated with more buried dung balls and an increase in the number of infective larvae stage 3 (L3) numbers in the herbage in the High dung beetle treatment. There was no evidence that <em>Copris incertus</em> reduced nematode larval numbers on pasture, regardless of beetle densities.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"337 ","pages":"Article 110500"},"PeriodicalIF":2.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bio-activities of Clerodendrum inerme extracts, essential oil, main terpenes and Ag nanoparticles against the stable fly, Stomoxys calcitrans (Diptera: Muscidae) and their non-target effects against its parasitoid, Spalangia cameroni (Hymenoptera: Pteromalidae) and earthworms","authors":"Saeed M. Alasmari ,&nbsp;Bader Z. Albogami ,&nbsp;Gomah E. Nenaah ,&nbsp;Shrook G. Nenaah","doi":"10.1016/j.vetpar.2025.110497","DOIUrl":"10.1016/j.vetpar.2025.110497","url":null,"abstract":"<div><div>The stable fly, <em>Stomoxys calcitrans</em>, is a cosmopolitan noxious dipteran hematophagous insect of veterinary and medical importance. There is a renewed interest to develop eco-friendly green pesticides to control stable flies while avoiding the health and environmental hazards of synthetic pesticides. In that framework, <em>Clerodendrum inerme</em> essential oil (EO) was produced by hydrodistillation, and analysed by using (GC-FID) and GC-MS). Isoeugenol (33.1 %) and dibutyl phthalate (29.3 %) were identified as the main components. Silver nanoparticles (<em>Ci</em>-based AgNPs were produced using the methanol (MeOH) extract and characterized using microscopic and spectroscopic instruments. The phytochemicals exhibited considerable insecticidal bioactivity towards <em>S. calcitrans</em>. Using topical application, <em>Ci</em>-based AgNPs displayed the strongest bioactivity, followed by EO, dibutyl phthalate, isoeugenol, MeOH, and aqueous extracts. At a test concentration of 160 µg/fly, <em>Ci</em>-based AgNPs and EO killed all insects after 24 h. The LC₅₀ values ranged between 41.1 and 124.6 µg/fly. Using fumigation, the EO was the strongest fumigant, followed by isoeugenol, <em>Ci</em>-based AgNPs, and dibutyl phthalate, where the 24 h fumigation LC_50’s ranged between 20.8 and 73.7 µL/L air. Botanicals substantially inhibited insects' acetylcholinesterase (AChE) bioactivity. Non-target effects revealed that the phytochemicals showed an acceptable safety margins towards the parasitoid, <em>Spalangia cameroni</em> with LC₅₀ values ranged between 988.18 and ˃ 2000 µL/mL. They were considered as safe for earthworms, <em>Eisenia fetida</em>, at concentration up to 200 mg/kg soil. The results confirm the potential of using <em>C. inerme</em> extracts, EO and nanoparticles as eco-friendly green insecticides against <em>S. calcitrans</em>.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"337 ","pages":"Article 110497"},"PeriodicalIF":2.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Psoroptes ovis mange in sheep: Organ and tissue weights as indicators of the impact on organismal metabolism, lymphatic system and body composition","authors":"Steffen Rehbein,&nbsp;Dietmar Hamel,&nbsp;Martin Visser,&nbsp;Renate Rauh","doi":"10.1016/j.vetpar.2025.110492","DOIUrl":"10.1016/j.vetpar.2025.110492","url":null,"abstract":"<div><div>Although adverse effects on the welfare, skin pathology and host immune responses of ovine psoroptic mange are well described, there is only limited research on the impact on the performance of the animals and underlying pathogenicity. To provide objective data on effects of the disease at organismal level, weights of organs and tissues of sheep included in a parasiticide study with groups of mange-infested, mange-infested and treated and non-infested animals were evaluated. For the study, 48 young Merino sheep were formed randomly into three equal-sized groups on sex and body weight - to develop mange without intervention (ʽinfestedʼ), to develop mange and treated 10 weeks after initial infestation (ʽinfested-treatedʼ) or to be prevented from mange infestation – and infested twice with <em>Psoroptes ovis</em> mites. Mange developed in all ʽinfestedʼ and ʽinfested-treatedʼ animals and was maintained by the ʽinfestedʼ animals throughout the study while the ʽinfested-treatedʼ animals became mite-negative four weeks after treatment. No mites established on the pre-infestation-treated sheep which served as ʽnon-infestedʼ controls for the analyses. At slaughter 16 weeks after the initial mite infestation, the ʽinfestedʼ animals had significantly (p &lt; 0.05) lower relative (organ/tissue weight divided by live weight) omental fat, perirenal fat and thymus weights and higher relative liver, adrenal glands, prescapular and precrural lymph nodes, gastrointestinal tract, metacarpus bone and skin weights than the ʽnon-infestedʼ animals. They also had significantly lower relative thymus and gastrointestinal tracts weights and higher relative adrenal glands, prescapular lymph nodes, precrural lymph nodes and skin weights than the ʽinfested-treatedʼ animals. The organ/tissue weights of the ʽinfested-treatedʼ animals indicated that many changes observed in the ʽinfestedʼ animals improved substantially within six weeks of treatment. Analysis of the organ weights demonstrates the impact of ovine psoroptic mange on protein and energy metabolism (lower adipose tissues and higher liver and adrenal glands weights as measures of increased demand for maintenance or chronic stress of the mite infestation) and defense mechanisms (lower thymus weight reflecting suppression from increased adrenal activity and higher weight of the peripheral lymph nodes as local reaction to the continuous exposure of antigens originating from the mite-induced exudative dermatitis). In addition, higher gastrointestinal tract plus skin weights and higher metacarpus bone weight leading to lower dressing percentage and higher carcass bone ratio, respectively, reflect the change in body composition and tissue disposition resulting in overall reduction in market value.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"337 ","pages":"Article 110492"},"PeriodicalIF":2.0,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143935904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative efficacy of imidocarb dipropionate with additive in naturally infected cattle against bovine babesiosis","authors":"Sajida Bibi ,&nbsp;Sidra Abbas ,&nbsp;Muhammad Arfan Zaman ,&nbsp;Roquyya Gul ,&nbsp;Aima Iram Batool ,&nbsp;Iqra Khalil ,&nbsp;Arbab Sikandar ,&nbsp;Farhan Ahmad Atif","doi":"10.1016/j.vetpar.2025.110495","DOIUrl":"10.1016/j.vetpar.2025.110495","url":null,"abstract":"<div><div>Babesiosis is a tick borne disease prevalent worldwide. The present study was planned to evaluate the therapeutic efficacy of imidocarb dipropionate alone and with additive milk, cumin, and jetepar syrup in naturally <em>Babesia</em>-infected cattle. Blood samples (n = 300) were collected from the selected cattle. Age, breed, dung pile location, use of acaricides, temperature, health status, tick infestation and housing type were also considered during sample collection. Out of 90 samples that were found positive through staining procedures, 45 were confirmed through PCR. As per infection rate observed more in exotic breed, the treatment trials were conducted on these cattle. These cattle were divided into three groups, each consisting of 15 cattle. Group 1 was treated with imidocarb dipropionate. Group 2 was treated with imidocarb dipropionate and additives (milk, cumin, and jetepar syrup). Group 3 was the infected, non-medicated group, and group 4 consisted of healthy, non-infected cattle (n = 15).The cattle were subjected to liver function tests and recorded milk production before and after treatment. The afore-mentioned factorsi.e. age (&lt;3 years), Holstein Friesian breed, with dung piles near their living area, without acaricides use, poor health status, tick infestation, and tethered housing system were found significant associated with babesiosis in the cattle. Cattle in G₁ treated with imidocarb dipropionate showed an efficacy of 60 %. G₂, on the other hand, showed 90 % efficacy. The cattle in G₃, did not recover and two died. All cattle in G₄, remained health. It was concluded that the cattle treated with imidiocarb dipropionate as well as additives showed better and rapid recovery.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"337 ","pages":"Article 110495"},"PeriodicalIF":2.0,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic parameters and haplotype-based genome-wide association study of indicator traits for gastrointestinal parasite resistance in Santa Ines sheep","authors":"Karine Assis Costa ,&nbsp;André Campêlo Araujo ,&nbsp;Pablo Augusto de Souza Fonseca ,&nbsp;Hugo Teixeira Silva ,&nbsp;Leonardo Sartori Menegatto ,&nbsp;Luara Afonso de Freitas ,&nbsp;Cleyce Maiara Cardoso ,&nbsp;Ivan Carvalho Filho ,&nbsp;Pamela Itajara Otto ,&nbsp;Ricardo Lopes Dias da Costa ,&nbsp;Nedenia Bonvino Stafuzza ,&nbsp;Claudia Cristina Paro de Paz","doi":"10.1016/j.vetpar.2025.110498","DOIUrl":"10.1016/j.vetpar.2025.110498","url":null,"abstract":"<div><div>Genetic parameters are of great importance in animal breeding since they determine the strategies necessary to increase the genetic progress in economic traits, for example indicator traits for resistance to endoparasites in sheep. Furthermore, genetic markers have been used to identify genomic regions associated with economically important traits, which can help increase the genetic response through genomic selection. Therefore, this study aimed to estimate genetic parameters and perform a haplotype-based genome wide association study (GWAS) to identify genomic regions associated with indicator traits for endoparasite resistance in Santa Ines sheep. Haplotype GWAS was performed using linkage disequilibrium blocks (haploblocks) defined by the Haploview software. Records from 1725 animals for Famacha© (FAM, N = 5560), packed cell volume (PCV, N = 5135), total plasma protein (TPP, N = 4356), and fecal egg count (FEC, N = 4248) were used for analysis. The pedigree file contained information from 4821 animals; of these, 638 animals were genotyped using the Ovine SNP50 Genotyping BeadChip. Heritability estimates were moderate for FAM (0.26), PCV (0.26), TPP (0.16), and log-transformed FEC (0.19). Genomic regions that explained more than 0.3 % of the total additive genetic variance of the traits were defined as significant. These regions overlapped with quantitative traits loci associated with eosinophil number, fecal egg count, hematocrit, and immunoglobulin levels. In the top regions for the traits evaluated we found genes individually involved in inflammatory response, immunity, macrophage function in host-pathogen interactions, and other biological functions. All indicator traits for resistance to gastrointestinal parasites evaluated in this study exhibited sufficient genetic variability to respond to selection and can be used to improve the health and consequently the production of Santa Ines sheep.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"337 ","pages":"Article 110498"},"PeriodicalIF":2.0,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143935903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to \"Infection mechanisms of Pochonia chlamydosporia: A breakthrough in Fasciola hepatica egg control\" [Vet. Parasitol. 337 (2025)110463].","authors":"Luyao Hao, Hongyou Liu, Fengmiao Zhao, Yuan Ma, Zhengyi Li, Rui Wang","doi":"10.1016/j.vetpar.2025.110496","DOIUrl":"https://doi.org/10.1016/j.vetpar.2025.110496","url":null,"abstract":"","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":" ","pages":"110496"},"PeriodicalIF":2.0,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144014584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to \"Multiple-species resistance to avermectin/milbemycin anthelmintics on beef cattle farms in Georgia, USA\" [Vet. Parasitol. 336 (2025) 110435].","authors":"Leonor Sicalo Gianechini, Kelsey L Paras, Melissa M George, Sue B Howell, Bob Storey, Matthew J Denwood, Ray M Kaplan","doi":"10.1016/j.vetpar.2025.110494","DOIUrl":"https://doi.org/10.1016/j.vetpar.2025.110494","url":null,"abstract":"","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":" ","pages":"110494"},"PeriodicalIF":2.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144026410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Worm replacement with susceptible Haemonchus contortus benefits weight gain, reduces anthelmintic treatments and impacts sheep breeds differently","authors":"Hornblenda Joaquina Silva Bello ,&nbsp;Rafaela Tami Ikeda Kapritchkoff ,&nbsp;Juliana de Carvalho Santos ,&nbsp;Glaucia Roberta Melito ,&nbsp;Simone Cristina Méo Niciura ,&nbsp;Sérgio Novita Esteves ,&nbsp;Flavia Aline Bressani ,&nbsp;Ana Carolina de Souza Chagas","doi":"10.1016/j.vetpar.2025.110490","DOIUrl":"10.1016/j.vetpar.2025.110490","url":null,"abstract":"<div><div>This study evaluated the effect of partial and total replacement of <em>Haemonchus contortus</em> in sheep breeds. Pregnant ewes of White Dorper (DO), Santa Inês (SI) and Texel (TX) breeds were allocated into three groups: Control (C), Partial Replacement (PR) and Total Replacement (TR). PR and TR ewes received anthelmintics (AH), were artificially infected with <em>H. contortus</em>-susceptible isolate and grazed on resistant-infested or worm-free paddocks, respectively. Control animals were untreated and naturally infected. 106 lambs were born and kept in the paddocks of their respective mothers. Their egg count per gram of feces (FEC) and packed cell volume (PCV) were recorded every 21 days, until 189 days old. Fecal Egg Count Reduction Test revealed AH efficacy of 85 %, 92 % and 97 % in the C, PR and TR groups, respectively, for ewes and 60 %, 74 % and 98 %, respectively, for lambs at day 147. SI animals (p &lt; 0.001) received fewer AH treatments and presented a higher PCV than DO and TX, reaching similar weight gain to the other breeds. Male lambs (p &lt; 0.001) presented a higher FEC, lower PCV and lower frequency of Famacha score 1. Higher age at weaning resulted in a lower FEC (p = 0.0073), higher PCV (p = 0.002), and higher frequencies of Famacha 1 and body condition scores 3 and 4. AH treatment was more efficient after worm replacement, reducing FEC (p &lt; 0.001) and favoring weight gain in the PR and TR groups. Avoiding early weaning, adopting selective AH treatments and using more resistant sheep breeds may delay the reestablishment of resistance after worm replacement.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"337 ","pages":"Article 110490"},"PeriodicalIF":2.0,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143917789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficacy of eprinomectin 5 mg/mL topical solution administered twice pour on at 1 mg per kg body weight against sarcoptic mange (Sarcoptes scabiei) in sheep","authors":"Smaragda Sotiraki ,&nbsp;Vaia Kantzoura ,&nbsp;Panagiota Ligda ,&nbsp;Ourania Baka ,&nbsp;Anastasios Saratsis ,&nbsp;Becky Fankhauser ,&nbsp;Katrin Kley ,&nbsp;Steffen Rehbein","doi":"10.1016/j.vetpar.2025.110489","DOIUrl":"10.1016/j.vetpar.2025.110489","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Sarcoptic mange of sheep is a skin disease which compromises the health and welfare of the animals, impacts their productivity and is zoonotic. In Europe, sarcoptic mange appears to be the prevailing type of mange affecting sheep kept for milk production in the Mediterranean countries. Eprinomectin 5 mg/mL topical solution (EPRINEX® Multi, Boehringer Ingelheim) was recently authorized for the treatment of gastrointestinal and pulmonary nematodes and &lt;em&gt;Oestrus ovis&lt;/em&gt; in sheep with zero hours milk withdrawal in several countries in Europe. As the product in cattle has claims against a broad range of parasites including sarcoptic mange mites, the therapeutic efficacy of the product was evaluated in dairy sheep with naturally acquired &lt;em&gt;S. scabiei&lt;/em&gt; infestation in two field efficacy study (25 sheep per study) and one controlled, masked clinical study (22 sheep) conducted in Greece. In the field studies, all animals were administered twice, two weeks apart (Days 0 and 14), eprinomectin 5 mg/mL topical solution at 14 mL per animal pour on, based on the body weight measured for the visually estimated heaviest five animals in each study. In the controlled study, animals were ranked by decreasing pre-treatment live mite count, formed in blocks of two animals and randomly assigned to one of two groups to remain untreated (control) or to be administered twice, two weeks apart, eprinomectin 5 mg/mL topical solution at 1 mL per 5 kg body weight pour on. Skin scrapings were collected prior to treatment and at intervals for eight weeks after the first treatment to establish live &lt;em&gt;Sarcoptes&lt;/em&gt; mite counts. A ʽMange Clinical Scoreʼ was established for each animal using a 5-category scoring system at each sampling. Mite counts of the eprinomectin 5 mg/mL topical solution-treated animals were significantly (p &lt; 0.0001) lower than the pre-treatment counts in the field studies or those of the controls in the controlled study, on all occasions post-treatment. All treated animals had zero live mite counts at 28 days after the first treatment and at the subsequent occasions until the end of the studies (Day 56). All untreated animals in the controlled study remained infested throughout the study. The ʽMange Clinical Scoreʼ of the eprinomectin 5 mg/mL topical solution-treated animals, compared either to the pre-treatment scores in the animals in the field studies or to the scores of the controls in the controlled study, improved significantly (p &lt; 0.05) from Day 7 or Day 14, respectively. At the end of the studies, 56 of the 61 treated sheep had healthy skin and did not show clinical symptoms associated with sarcoptic mange, while five animals still presented small, reddened skin areas and some itching despite demonstrating zero mite counts over four weeks. The administration of the treatments was well accepted by all animals and no health problems were observed throughout the studies. This series of studies demonstrated eprinomectin 5 mg/m","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"337 ","pages":"Article 110489"},"PeriodicalIF":2.0,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143917788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acaricidal activity of Myrcia splendens essential oils on Rhipicephalus microplus larvae","authors":"Hismirllei Santana Lima Gonçalves ,&nbsp;Aline do Nascimento Silva ,&nbsp;Mariana Borges Botura ,&nbsp;Daniele Silva Souza Carreira ,&nbsp;Rosângela Soares Uzêda ,&nbsp;Angélica Maria Lucchese","doi":"10.1016/j.vetpar.2025.110491","DOIUrl":"10.1016/j.vetpar.2025.110491","url":null,"abstract":"<div><div><em>Rhipicephalus microplus</em> is a major pest in Brazilian livestock, causing significant economic losses. Current control methods have drawbacks such as high costs, the need for specialized professionals and variable product effectiveness. <em>Myrcia splendens</em> extracts and essential oils are known for their antimicrobial properties, but there is no research on their acaricidal activity. This study aimed to investigate the chemical composition, acaricidal, anticholinesterase and cytotoxic activities of essential oils from two chemotypes (A and B) of <em>M. splendens</em>. Chemical composition was analyzed by Gas Chromatography coupled with Flame Ionization Detection (GC/FID) and Mass Spectrometry (GC/MS). The analysis revealed that the essential oils were rich in sesquiterpenes, with carotol (18.08 %) being predominant in chemotype A, while (2<em>E</em>,6<em>E</em>)-methyl farnesoate (42.64 %) was predominant in chemotype B. The oils exhibited acaricidal activity against <em>R. microplus</em> larvae in a concentration-dependent manner, with chemotype A showing the highest potency (LC₅₀ = 4.06 mg/mL). The oils also inhibited acetylcholinesterase activity (p &lt; 0.05), a potential target for acaricides, with chemotype B showing greater activity (IC₅₀ = 0.14 mg/mL), suggesting this as a mechanism for their acaricidal effect. Cytotoxicity testing in Vero cell cultures showed that only chemotype A reduced cell viability by 19 % at the highest concentration (2 mg/mL). In conclusion, <em>M. splendens</em> essential oils exhibit <em>in vitro</em> anti-tick activity with low toxicity, with chemotype A being more effective.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"337 ","pages":"Article 110491"},"PeriodicalIF":2.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}