Veterinary parasitology最新文献

{"title":"Comparative analysis of the viability of Fasciola hepatica eggs collected from fecal and gallbladder samples in experimentally infected sheep","authors":"S. Ortega-Vargas ,&nbsp;I. Cruz-Mendoza ,&nbsp;J.A. Figueroa-Castillo ,&nbsp;A.V. Balderas-Loaeza ,&nbsp;A. Villa-Mancera ,&nbsp;F. Utrera-Quintana ,&nbsp;H. Quiroz-Romero","doi":"10.1016/j.vetpar.2025.110631","DOIUrl":"10.1016/j.vetpar.2025.110631","url":null,"abstract":"<div><div>The objective of this study was to determine and compare the viability of <em>Fasciola hepatica</em> eggs collected from fecal and gallbladder samples through the egg hatching test of experimentally infected sheep. The biological samples used come from a previously reported sheep vaccination trial. Twenty-five sheep free of fasciolosis and housed in pens with cement floors were used. The sheep were grouped into five groups (G1–5, n = 5 sheep per group). Groups G1(100 ug), G2 (200 ug), G3 (400 ug) were immunized with the chimeric protein (rFhLAP-CL1) and, groups G4 and G5 were the adjuvant and infection controls, respectively. All sheep were orally infected with 200 metacercariae. The experimental period was 24 weeks. <em>Fasciola hepatica</em> eggs were collected every 15 days from fecal samples from weeks 14–24 of the experiment, and from the gallbladder after euthanized. The viability of <em>F. hepatica</em> eggs was determined through an egg hatching assay (EHA). Eggs that had developed miracidium and hatched were considered viable eggs. The viability range of <em>F. hepatica</em> eggs from gallbladder was 22–59.6 % and of fecal samples was 67–88 %. The viability of <em>F. hepatica</em> eggs from fecal samples was higher (&gt;90 %) than that of eggs from the gallbladder (&lt;60 %). In the vaccination trial, the viability of <em>F. hepatica</em> eggs in the G3 group was significantly different compared to the control group, in fecal samples (p &lt; 0.001) and in the gallbladder (p &lt; 0.05). Higher viability of <em>F. hepatica</em> eggs was observed in fecal samples than in gallbladder samples. Fecal samples are suggested for determining the viability of trematode eggs in vaccination trials or evaluation of fasciolicides.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"340 ","pages":"Article 110631"},"PeriodicalIF":2.2,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145318618","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":"Chi-miR-146a promotes the propagation of Neospora caninum by targeting the TGF-β1/SMAD2 pathway","authors":"Jin-Ming Chen,&nbsp;Jing-Yu Li,&nbsp;Jia-Yi Jin,&nbsp;Xiao-Qi Bao,&nbsp;De-Liang Tao,&nbsp;Xiao-Yun Zhao,&nbsp;Jun-Ke Song,&nbsp;Xin Yang,&nbsp;Ying-Ying Fan,&nbsp;Guang-Hui Zhao","doi":"10.1016/j.vetpar.2025.110632","DOIUrl":"10.1016/j.vetpar.2025.110632","url":null,"abstract":"<div><div><em>Neospora caninum</em> is known to induce abortions in various domestic animals (especially cattle and sheep), leading to substantial economic losses in the livestock industry. However, effective strategies for controlling <em>N. caninum</em> infection remains elusive. The precise mechanisms underlying the interaction between <em>N. caninum</em> and its host are not fully elucidated. Our previous study showed an upregulated microRNA (miRNA), Chi-miR-146a, promoted the propagation of <em>N. caninum</em> tachyzoites in caprine endometrial epithelial cells (EECs). The present study investigated its regulatory function during <em>in vitro</em> infection of <em>N. caninum</em>. The expression of Chi-miR-146a was upregulated from 12 h post infection (hpi) to 48 hpi. One of target genes for Chi-miR-146a, <em>tgfb1</em>, was identified and the mRNA and protein levels were downregulated at 24 hpi and 48 hpi. Overexpression of <em>tgfb1</em> suppressed the propagation of <em>N. caninum</em> tachyzoites in caprine EECs. Further analysis indicated that Chi-miR-146a enhanced <em>in vitro</em> propagation of <em>N. caninum</em> propagation through suppressing the activation of the TGF-β1/SMAD2 signaling pathway. The findings in this study offer a novel theoretical framework for advancing our understanding on mechanisms of intracellular survival of <em>N. caninum</em> and devising preventive strategies against this pathogen.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"340 ","pages":"Article 110632"},"PeriodicalIF":2.2,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324369","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":"Anthelmintic efficacy and sublethal effects of trichlorfon in pirarucu (Arapaima gigas) naturally infected with Dawestrema cycloancistrium","authors":"Jeffesson de Oliveira-Lima ,&nbsp;Patricia Oliveira Maciel-Honda ,&nbsp;Jayne Barros de Aguiar Silva ,&nbsp;Liana Bezerra Dias de Lima ,&nbsp;Sandro Estevan Moron","doi":"10.1016/j.vetpar.2025.110630","DOIUrl":"10.1016/j.vetpar.2025.110630","url":null,"abstract":"<div><div>Trichlorfon is an organophosphate commonly used to control fish ectoparasites due to its cholinesterase-inhibiting action. Due to recurring issues with monogeneans in pirarucu, this active ingredient has been frequently used in this aquaculture system. The present study aimed to simultaneously evaluate the antiparasitic efficacy and physiological effects of trichlorfon in <em>A. gigas</em> juvenile naturally infected with monogenean <em>Dawestrema cycloancistrium</em>. In the <em>in vitro</em> assay, parasitized gill arches were exposed to trichlorfon (0.1 mg/L - 10 g/L) under controlled conditions, with parasite motility analyzed every 30 min. A 100 % mortality rate was observed after 30 min at 10 g/L and after 3 h at 10 mg/L; concentrations ≤ 1 mg/L caused only a reduction in parasite motility. In the <em>in vivo</em> trial, 96 juveniles were separated into four groups: control, 10 g/L for 30 min, 10 mg/L for 3 h and 10 mg/L for 96 h. The 10 mg/L for 96 h treatment showed the highest efficacy (96.9 %), significantly surpassing the others (49.7 % and 42.3 %; p &lt; 0.05). However, this prolonged exposure induced hypochromic anemia, leukopenia, reduction in ALT and AST levels, and hyperglycemia. It is concluded that trichlorfon short-bath protocols, such as 10 g/L for 30 min or 10 mg/L for 3 h did not cause significant physiological alterations but resulted in only partial efficacy (∼50 %). Prolonged exposures at 10 mg/L for 96 h should not be recommended for <em>A. gigas</em> due to their hematotoxic and hepatotoxic effects.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"340 ","pages":"Article 110630"},"PeriodicalIF":2.2,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145318616","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 plant-based remedies for Varroa destructor control in honey bee colonies: A preliminary study","authors":"Ľubomír Korený,&nbsp;Michaela Korená Hillayová,&nbsp;Jaroslav Škvarenina","doi":"10.1016/j.vetpar.2025.110629","DOIUrl":"10.1016/j.vetpar.2025.110629","url":null,"abstract":"<div><div>The Western honey bee (<em>Apis mellifera</em> L.) plays a crucial role in global ecosystems and agriculture, yet the ectoparasitic mite <em>Varroa destructor</em> remains a primary cause of severe varroosis and significant colony morbidity and mortality. Current reliance on synthetic acaricides often leads to the development of mite resistance and raises concerns regarding chemical residues in hive products. This has created an urgent need for innovative and effective veterinary strategies for parasite control. This study investigated the efficacy of traditional plant-based remedies as an alternative treatment for <em>V. destructor</em> infestations in honey bee colonies. Herbal decoctions from medicinal plants (e.g., nettle, clove, linden, peppermint, lavender, sage, dandelion), known for their anti-parasitic properties, were applied to bee colonies via aerosol. <em>V. destructor</em> infestation levels were monitored monthly using a non-destructive CO₂-induced narcosis method. Statistical analysis, specifically a Linear Mixed Model (LMM), revealed a significant decrease in mean <em>Varroa</em> infestation from 1.8 % in 2021–1.1 % in 2023 across the experimental colonies (<em>p</em> &lt; 0.000001 for year effect). Furthermore, the LMM confirmed significant differences in efficacy among the tested decoctions (<em>p</em> &lt; 0.000001 for Decoction label effect), with specific extracts (DIII and DV) demonstrating superior performance. These findings highlight a validated, ecologically derived phytotherapeutic approach for <em>Varroa</em> management, demonstrating its potential to significantly reduce mite populations over multiple years without adverse effects on honey bee health. This research provides valuable insights into natural alternatives for parasitic mite control in domesticated animals like honey bees.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"340 ","pages":"Article 110629"},"PeriodicalIF":2.2,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145309398","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":"Smart farming with AI: Enhancing anemia detection in small ruminants","authors":"Sadia Farhana","doi":"10.1016/j.vetpar.2025.110627","DOIUrl":"10.1016/j.vetpar.2025.110627","url":null,"abstract":"","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"340 ","pages":"Article 110627"},"PeriodicalIF":2.2,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267373","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":"In vitro and in silico studies of GST-inhibitory and larvicidal activities of alkaloids against Rhipicephalus microplus","authors":"Amanda Ponce Morais Cerqueira ,&nbsp;Matheus da Cunha Santos ,&nbsp;Gabriel Lima Soares Rezende ,&nbsp;Manoelito Coelho dos Santos Junior ,&nbsp;Mariana Borges Botura","doi":"10.1016/j.vetpar.2025.110628","DOIUrl":"10.1016/j.vetpar.2025.110628","url":null,"abstract":"<div><div>The resistance of <em>Rhipicephalus microplus</em> to the main commercial acaricides has stimulated research for new antiparasitic agents, including natural products as an alternative to eco-friendly control. Among the main classes of secondary metabolites of plants stand out the alkaloids, which are characterized by a variety of biological activities such as enzymatic inhibition. The enzyme Glutathione-<em>S</em>-transferase (GST) is an important catalyst of xenobiotic detox reactions in arthropods and represents a promising target in the acaricide development. This work aimed to associate <em>in silico</em> and <em>in vitro</em> assays for the identification of alkaloids with inhibitory action against GST from <em>R. microplus</em> (RmGST). The model of RmGST was designed using the SWISS-MODEL online server and validated by molecular dynamics. The molecular affinity of alkaloids with RmGST was assessed using the DOCK 6.9 program and the best molecules were employed in <em>in vitro</em> assays. The <em>in vitro</em> assays performed were enzymatic inhibition and larval immersion tests. Molecular dynamics was run with GROMACS for alkaloid selected from <em>in silico</em> and <em>in vitro</em> analyses. The RmGST model shown to be sterically and energetically acceptable. In molecular dynamics simulations, the 3D structure remains stable with Root Mean Square Deviation = 4.35 Å and Root Mean Square Fluctuation = 2.21 Å. All the 20 alkaloids tested in molecular docking analyses show molecular affinity to the RmGST. Colchicine and papaverine show the best GridScocre: −38.09 and −36.09 kcal/mol, respectively. In <em>in vitro</em> enzymatic evaluation, colchicine exhibited more activity (81.73 %, 0.5 mg/mL) in comparison to papaverine (27.8 %, 0.5 mg/mL). However, these alkaloids did not interfere <em>in vitro</em> with the viability of <em>R. microplus</em> larvae. The colchicine contributed to the stability of the RmGST model in molecular dynamics simulations and presented hydrophobic and hydrogen interactions with residues from the orthosteric site. The association of <em>in silico</em> and <em>in vitro</em> techniques allowed the identification of two potential RmGST inhibitors (colchinine and papaverine) capable of interacting in the active site of the enzyme. RmGST inhibitors can be used in association with acaricides for a more effective control of <em>R. microplus</em> reducing parasite resistance.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"340 ","pages":"Article 110628"},"PeriodicalIF":2.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145259323","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":"Synergistic in vitro effects of albendazole and minocycline on the viability of hydatid cyst protoscoleces","authors":"Nafiseh Hajiheidari ,&nbsp;Hossein Amini Khoei ,&nbsp;Kobra Mokhtarian ,&nbsp;Ebrahim Saedi Dezaki","doi":"10.1016/j.vetpar.2025.110624","DOIUrl":"10.1016/j.vetpar.2025.110624","url":null,"abstract":"<div><div>Hydatid disease poses a major zoonotic threat, affecting human health and livestock. Although albendazole is the standard treatment, it may cause adverse effects at high serum levels. This study investigated the protoscolicidal efficacy of minocycline alone and in combination with albendazole, compared to albendazole monotherapy, on hydatid cyst protoscoleces from sheep liver. Protoscoleces were aseptically aspirated from the sheep livers containing hydatid cysts. A total of 30,000 protoscoleces were suspended in 300 µl of normal saline and exposed to various concentrations of minocycline (10, 25, 50, 75, 125, 250, and 500 µg/ml) and albendazole (31.25, 62.5, 125, 250, 500, 1000, and 2000 µg/ml) for 10, 30, and 60 min, and subsequently from 1 h up to 43 h of incubation, in triplicate. The viability of the protoscoleces was assessed using 0.1 % eosin staining. The combination of Minocycline and Albendazole significantly reduced protoscoleces viability (P &lt; 0.05). All the treatment groups demonstrated progressive reductions in cell viability over time. Notably, combination therapy reduced viability to zero at 22 h, wherase Albendazole and Minocycline alone reached 0 % and 1.3 % viability, respectively, at 43 h. The combination of minocycline and albendazole produced significantly, partially, stronger scolicidal activity than either monotherapy, achieving complete protoscolex mortality within ∼22 h compared with 43 h for albendazole and incomplete killing with minocycline alone (P &lt; 0.05). These findings suggest that this drug combination may enhance treatment efficacy for hydatid disease and warrants further in vivo evaluation.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"340 ","pages":"Article 110624"},"PeriodicalIF":2.2,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145245490","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":"Comparison of the protective immune response of Live vs. inactivated NC-a strain as an experimental vaccine for Neospora caninum in Balb/c mice","authors":"Matin Khosropour ,&nbsp;Mehdi Namavari ,&nbsp;Salomeh Shirali ,&nbsp;Zahra Bootorabi ,&nbsp;Zahra Khabazan","doi":"10.1016/j.vetpar.2025.110625","DOIUrl":"10.1016/j.vetpar.2025.110625","url":null,"abstract":"<div><div>Developing an effective vaccine for Neosporosis is critical for its control and prevention. Our previous research introduced the attenuated strain prepared by long-term passage on the J774 cell line (NC-a) that yielded successful results in terms of protective immune response in mice. Given the preference for inactivated over live vaccines, this study evaluated the NC-a strain in its inactivated form (I. NC-a) with different adjuvants in a Balb/c mouse. Fifty Balb/c mice were randomly divided into five groups: G1 (I. NC-a with aluminum hydroxide), G2 (I. NC-a with Montanide ISA 70), G3 (I. NC-a without adjuvant), G4 (live NC-a), and G5 (negative control). Mice were immunized twice, 21 days apart, with 2 × 10⁶ NC-a tachyzoites, followed by a challenge with 2.5 × 10⁶ virulent NC-1 tachyzoites. Survival rates, serological tests assessing humoral and cellular immune responses and also, molecular testing were conducted. Serological results revealed that, there was a significant difference (P &lt; 0.05) between the vaccinated groups and the G5, as well as between adjuvanted inactivated vaccine groups (G1, G2) and the live vaccine group (G4). Also, the survival rate of mice in group G2 and G4 was about 90 %. In general, an important point is the adjuvant-inactivated strain induced comparable and potentially superior protective immune responses to the live strain. These results highlight the promise of inactive vaccines and suggest that complementary research could lead to a functional and safe neosporosis vaccine for various hosts, diverging from the focus on live vaccines dominant in protozoan studies.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"341 ","pages":"Article 110625"},"PeriodicalIF":2.2,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145420122","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 fluralaner against natural infestations of Haemaphysalis longicornis and Rhipicephalus sanguineus in dogs under field conditions in China","authors":"Jie Hu ,&nbsp;Yanyang Yuan ,&nbsp;Famiao Zeng ,&nbsp;Ming Yang ,&nbsp;Zhuo Chen ,&nbsp;Zhihui Hao","doi":"10.1016/j.vetpar.2025.110626","DOIUrl":"10.1016/j.vetpar.2025.110626","url":null,"abstract":"<div><div>Tick infestations compromise canine health and facilitate zoonotic pathogen transmission. This randomized, investigator-blinded, multicenter field study evaluated the efficacy and safety of fluralaner chewable tablets against natural tick infestations in dogs in China. Dogs naturally infested with ≥ 5 ticks were enrolled and randomized 1:1 to receive either a laboratory-developed fluralaner chewable tablet (experimental) or the reference product BRAVECTO® (control), with dosing according to body-weight bands. At baseline (Day 0), whole-body tick counts (≥10 min), lesion-severity scoring, and microscopic identification of a tick subsample were performed; follow-up assessments occurred on Days 7, 14, 28, 56, and 84, with the final visit on Day 56 for dogs infested with <em>Rhipicephalus sanguineus</em> and on Day 84 for those with other species, notably <em>Haemaphysalis longicornis</em>. A total of 120 dogs were enrolled, and two tick species were identified: <em>H. longicornis</em> and <em>R. sanguineus</em>. Relative to baseline, mean tick counts were reduced by 99.95 % (experimental) and 99.83 % (control); 98.33 % of dogs were tick-free on Day 7, and 100 % were tick-free from Day 14 through the final visit (Day 56/84). Skin lesions improved significantly, with complete resolution by Day 28 and no recurrence thereafter. No treatment-related adverse events were observed. These findings indicated that fluralaner chewable tablets provided effective control of natural tick infestations and achieved complete tick-free status for 12 weeks against <em>H. longicornis</em> and 8 weeks against <em>R. sanguineus</em> under field conditions.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"340 ","pages":"Article 110626"},"PeriodicalIF":2.2,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145318629","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":"Timing is everything – Choosing the right time to screen the herd for neosporosis","authors":"Sharon Tirosh-Levy ,&nbsp;Elena Blinder ,&nbsp;Jacob Joost Doekes ,&nbsp;Monica L. Mazuz","doi":"10.1016/j.vetpar.2025.110622","DOIUrl":"10.1016/j.vetpar.2025.110622","url":null,"abstract":"<div><div>Neosporosis is a major cause of abortions in cattle, leading to economic losses. As no effective treatment or vaccine is currently available, the only strategy to reduce the impact of neosporosis in endemic herds is implementation of control programs, based on serological surveillance. This study aimed to determine the optimal timing for serological testing. Sera were collected from 132 heifers at three farms at three months intervals, between the ages 5 and 28 months. <em>Neospora</em> serological status and antibody titers were evaluated by IFAT, and by ELISA on the first sampling. The agreement between ELISA and IFAT results was 89.9 % (Kappa=0.798). Overall <em>Neospora</em> seroprevalence ranged between 36 % and 66 % on different dates. The antibody titers of almost all heifers fluctuated over time. Of 91 heifers that were sampled on 5 occasions, 67 % maintained their serological status throughout the study. Most cases of negative heifers that become positive in one or more tests (19 of 21 heifers) were transient, while only three remained persistently infected in all further tests. Seropositivity was significantly lower in lactating cows than in pregnant cows or heifers. The results of the first sampling date were representative of the overall status on all dates, with an agreement of 94.5 % (Kappa=0.889). The results demonstrate how fluctuations in antibody titers may affect the sensitivity of serological surveillance. Sampling young heifers, prior to their first insemination may be advisable, allowing future discrimination between what appear to be new infection, which is mostly transient, and congenital or chronic infections, which are usually life-long. This information may assist in the implementation of effective control measures in the herd.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"340 ","pages":"Article 110622"},"PeriodicalIF":2.2,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145252985","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}