Veterinary World最新文献

Background and aim: Canine pyoderma is a common dermatological condition, often caused by Staphylococcus pseudintermedius and related methicillin-resistant strains (MRSP and MRSS). Rising antimicrobial resistance necessitates alternative topical therapies. This study comparatively evaluated the in vitro antibacterial activity of P. betel leaf extract (both solvent-based and nanoemulsion forms) and cannabidiol (CBD) formulations against canine Staphylococcus isolates.

Materials and methods: Antibacterial activity was determined by broth microdilution to establish minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Five formulations were tested: Ethanolic betel leaf extract in dimethyl sulfoxide betel leaf (BL), BL extract nanoemulsion (BLN), CBD in ethanol, water-soluble CBD, and CBD nanoemulsion. Test organisms included 15 Staphylococcus isolates (five MRSP, five methicillin-susceptible S. pseudintermedius, and five MRSS) and five Pseudomonas aeruginosa. Gas chromatography-mass spectrometry (GC-MS) was used to characterize phytochemical constituents.

Results: GC-MS revealed eugenol (40.86%) and hydroxychavicol (26.44%) as predominant antibacterial compounds. BL and BLN demonstrated potent anti-staphylococcal activity, with median MICs of 0.16 g/L and 0.31 g/L, respectively. BL exhibited significantly lower MIC and MBC values than BLN (p = 0.008). Among CBD formulations, ethanol-dissolved and water-soluble CBD displayed the strongest activity (median MICs 0.003 g/L and 0.004 g/L), while CBD nanoemulsion was markedly less effective (median MIC 7.50 g/L). BLN also exhibited antibacterial activity against P. aeruginosa (median MIC 0.62 g/L), comparable to BL.

Conclusion: The novel BLN and soluble CBD formulations demonstrated significant in vitro antibacterial activity against methicillin-resistant Staphylococcus isolates from canine pyoderma. These results highlight their potential as topical antiseptic alternatives to chlorhexidine. Further in vivo studies are required to assess safety, efficacy, and formulation optimization. A combined betel-CBD nanoemulsion represents a promising direction for developing novel veterinary dermatological therapies.

Background and aim: Sheep farming is a vital component of Indonesia's agricultural economy, where the demand for meat continues to rise. Indigenous Garut sheep are well-adapted to local environments and are known for their high reproductive efficiency, but they have low growth rates. Conversely, Dorper sheep are renowned for their rapid growth and carcass quality, but they exhibit longer lambing intervals under tropical conditions. Crossbreeding offers a strategy to combine the strengths of both breeds. This study aimed to evaluate maternal reproductive performance and pre-weaning growth traits in purebred Dorper, Garut, and Dorper × Garut crossbred sheep under a commercial breeding system in Indonesia.

Materials and methods: A retrospective observational study was conducted on 1,744 ewes (1,498 Garut, 209 F1 Dorper × Garut, and 93 Dorper) and 3,248 lambs (2,846 F1 Dorper × Garut, 253 B1 backcrosses, and 149 Dorper) from a commercial enterprise in West Java. Data included lambing interval, litter size, birth weight, weaning weight, pre-weaning mortality, average daily gain (ADG), reproductive index, and productivity index. Statistical analyses employed one-way analysis of variance with Duncan's multiple range test for post hoc comparisons.

Results: F1 Dorper × Garut crossbred ewes demonstrated significantly shorter lambing intervals (206.65 ± 2.75 days) than pure Dorper (265.66 ± 1.14 days), comparable to Garut ewes (209.10 ± 1.08 days). However, Garut ewes had superior litter size (1.77 ± 0.18) relative to both crossbred (1.33 ± 0.04) and Dorper ewes (1.30 ± 0.42). In growth performance, Dorper lambs excelled in birth weight (3.35 ± 0.07 kg), weaning weight (23.93 ± 0.57 kg), and ADG (203.88 ± 4.65 g/day). F1 Dorper × Garut lambs showed significantly higher weaning weight (19.48 ± 0.35 kg) and ADG (165.34 ± 2.95 g/day) compared with Garut lambs (15.36 ± 0.10 kg; 130.47 ± 0.83 g/day).

Conclusion: F1 Dorper × Garut crossbreeding synergizes Garut's reproductive efficiency with Dorper's growth performance, yielding crossbreds well-suited for tropical meat production. While Garut maintains a prolificacy advantage, F1 crossbreds deliver improved pre-weaning growth, supporting their use in commercial fattening programs. Maintaining pure Garut flocks for breeding and employing F1 crossbreds for production may enhance productivity and sustainability in Indonesia. Future research should assess carcass traits, multigenerational crossbreeding, and economic feasibility.

Background and aim: Veterinary biobanking advances translational research, companion animal health, and the ethical reuse of samples. Its success depends on public engagement and the pet owners' willingness to contribute biological samples. However, awareness and attitudes toward veterinary biobanking remain largely unexplored in the Baltic region. This study aimed to assess Latvian pet owners' awareness, willingness to donate, motivations, and concerns regarding veterinary biobanking, and to identify demographic and professional factors influencing participation.

Materials and methods: A cross-sectional online survey was distributed through social media and veterinary clinics across Latvia between April and May 2025. The questionnaire included 49 items covering awareness, willingness to donate, motivations, concerns, and demographics. Data from 164 pet owners were analyzed using descriptive statistics, the Chi-square tests with Bonferroni correction, and logistic regression.

Results: Only 22% of respondents had prior awareness of veterinary biobanks. Despite this, 76% were willing to donate samples if their pet was seriously ill, and 67% even if their pet was healthy. Motivations included altruism (helping other animals), supporting veterinary research, and potential treatment benefits for their own pets. Key concerns centered on confidentiality (91%), the right to withdraw samples (60%), and control of sample use (45%). Professional background was significantly associated with both awareness (p = 0.0004) and willingness to donate (p = 0.0013). Logistic regression confirmed that respondents in medical or veterinary professions were more likely to support donation (odds ratio = 3.31, 95% confidence interval = 1.54-7.12, p = 0.002). No significant associations were found with age, gender, education, or religion.

Conclusion: This first Baltic survey reveals that Latvian pet owners strongly support veterinary biobanking despite limited awareness. Altruism and the expected benefits of research drive participation, while ethical expectations regarding confidentiality, consent, and transparency remain crucial. The findings provide a foundation for developing national veterinary biobanking strategies, improving public communication, and integrating Latvia into European One Health and translational research infrastructures.

Background and aim: Opisthorchiasis and metorchiasis are significant zoonotic fish-borne trematodiases caused by Opisthorchis felineus and Metorchis bilis. These parasites exhibit overlapping geographic ranges and morphologically similar larval stages, complicating species-level identification. In Kazakhstan, where raw or undercooked freshwater fish is widely consumed, opisthorchiasis remains an endemic concern. This study aimed to investigate the prevalence of O. felineus and M. bilis in cyprinid fish from Akmola Region and to establish molecular tools for their differential diagnosis.

Materials and methods: A total of 818 freshwater cyprinid fish were collected from Lakes Sholak, Esey, and Karazhar between 2021 and 2023. Muscle tissue was examined using the compression method for metacercariae detection. Morphological identification was complemented with a newly designed multiplex polymerase chain reaction (PCR) assay targeting the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene. Selected amplicons were sequenced and subjected to phylogenetic analysis. Prevalence and infection intensity were calculated, and statistical comparisons were made among fish species and lakes.

Results: Opisthorchiidae metacercariae were detected in ide, bream, and roach, with prevalence varying across lakes. Lake Sholak exhibited the highest infection rate (42.9%), with ide showing the greatest susceptibility (40.4%). No infections were detected in fish from Lake Karazhar. Morphological differentiation between O. felineus and M. bilis was inconclusive due to overlapping features. Multiplex PCR successfully distinguished O. felineus (307 bp) from M. bilis (252 bp), with >99% sequence identity to GenBank references. Two representative sequences (PQ669120 and PQ669125) were deposited in GenBank. Phylogenetic analysis confirmed distinct clustering of both species.

Conclusion: This study provides the first molecular confirmation of O. felineus and M. bilis in freshwater fish of the Akmola region, Kazakhstan. The developed multiplex PCR assay offers a sensitive and reliable diagnostic tool for species-level differentiation. These findings highlight moderate to high prevalence in local fish, underline the zoonotic risks associated with fish consumption, and emphasize the need for integrated One Health surveillance to inform control strategies and food safety policies.

Background and aim: Newcastle disease (ND), caused by velogenic viscerotropic ND virus (VVNDV), remains a major threat to global poultry production, with outbreaks persisting even in vaccinated flocks. No approved antiviral therapy exists for ND, highlighting the urgent need for effective interventions. Favipiravir, a broad-spectrum RNA polymerase inhibitor, has shown promise against several RNA viruses. This study evaluated the toxicity, antiviral efficacy, and molecular mechanisms of favipiravir against VVNDV in an in ovo model.

Materials and methods: Specific pathogen-free embryonated chicken eggs (9-10 days old) were inoculated with VVNDV and treated with graded doses of favipiravir (75-2280 mg/kg/egg biomass). Toxicity was assessed through embryo survival, relative weight, morphological scoring, biochemical markers, and histopathology of liver tissues. Antiviral efficacy was evaluated through embryo survival, growth, hemagglutination (HA) titers, and 50% egg infectious dose (EID₅₀). Molecular docking was performed to characterize favipiravir's interaction with viral RNA-dependent RNA polymerase (RdRp). Statistical analyses included Kruskal-Wallis, analysis of variance, and correlation tests.

Results: Favipiravir displayed dose-dependent toxicity, with the highest dose (2,280 mg/kg) significantly reducing embryo survival (p = 0.027) and inducing hepatic necrosis and elevated alkaline phosphatase and urea levels. In contrast, therapeutic doses of 300 and 600 mg/kg achieved 100% embryo survival, significant weight gains, and complete viral suppression, with undetectable HA activity and EID₅₀ values. Favipiravir demonstrated antiviral efficacy by suppressing viral replication and conferring protection against VVNDV. Docking analysis revealed a strong binding affinity of favipiravir to RdRp, primarily mediated by electrostatic interactions and hydrogen bonding with residues Arg1189, Tyr1192, and Ser1288, suggesting inhibition of viral RNA synthesis.

Conclusion: This study provides the first in ovo evidence of favipiravir's efficacy against VVNDV, demonstrating complete viral inhibition at optimized doses while emphasizing the importance of dose-dependent toxicity monitoring. These findings establish favipiravir as a promising antiviral candidate for ND virus control and potentially other RNA viruses of veterinary and One Health importance. Further in vivo and field-based studies are warranted to validate its safety, optimize dosing regimens, and evaluate large-scale applicability in poultry production.

Background and aim: Porcine reproductive and respiratory syndrome virus (PRRSV) remains a major economic threat to the global swine industry, causing reproductive losses and severe respiratory illness. Accurate and cost-effective diagnostic tools are essential for timely detection and genetic monitoring, particularly in resource-limited settings. This study aimed to (i) establish a nested reverse transcription polymerase chain reaction (RT-PCR) assay targeting the open reading frame 7 (ORF7) gene to detect and differentiate PRRSV-1 and PRRSV-2, and (ii) refine the genetic classification of PRRSV-2 strains circulating in Thailand through ORF5-based phylogenetic analysis.

Materials and methods: A nested RT-PCR assay was developed using external primers for general PRRSV detection and internal primers specific to PRRSV-1 and PRRSV-2. Analytical specificity was assessed against modified-live vaccines, clinical isolates, and heterologous swine viruses (swine influenza virus and foot-and-mouth disease virus). Diagnostic accuracy was evaluated using 96 clinical serum samples and compared with a commercial real-time RT-PCR kit. To confirm genotyping capability, ORF7-positive samples underwent ORF5 sequencing and phylogenetic analysis. In addition, 386 complete ORF5 sequences (2000-2023) from Thai isolates and global references were analyzed using maximum likelihood methods to refine lineage and sublineage classification.

Results: The nested ORF7 RT-PCR assay demonstrated high specificity without cross-amplification and achieved 100% concordance with real-time RT-PCR, confirming its diagnostic reliability. Among the clinical samples, PRRSV-1, PRRSV-2, and mixed infections were successfully detected. Sequencing confirmed strain identities and revealed close similarity with both endemic and vaccine-related strains. Phylogenetic analysis classified Thai PRRSV-2 strains into five lineages (L1, L5, L8, L9, L10) and five sublineages (L1I, L5A, L8C, L8E, L9D). Notably, this study is the first to report sublineages L8C and L9D in Thailand, while also documenting a lineage shift from L8E to L10 as the predominant circulating strain.

Conclusion: The integration of nested ORF7 RT-PCR with ORF5-based phylogenetic analysis provides a sensitive, affordable, and reliable diagnostic platform for PRRSV detection and genetic classification. These findings enhance understanding of PRRSV-2 diversity in Thailand, highlight emerging sublineages, and underscore the importance of continuous molecular surveillance to inform vaccine strategies and disease control policies.

Background and aim: Canine babesiosis, primarily caused by Babesia canis vogeli in Thailand, is a significant tick-borne disease of veterinary concern. Molecular diagnostics targeting the 18S rRNA gene have enhanced detection sensitivity and specificity compared to conventional methods. This study aimed to identify and characterize B. canis vogeli in naturally infected dogs in Khon Kaen, Thailand, to compare the diagnostic performance of two primer sets (Bab7/Bab9 and Babf/Babc), and to perform phylogenetic analysis of the isolates.

Materials and methods: A total of 159 ethylenediaminetetraacetic acid blood samples from client-owned dogs presented to the Veterinary Teaching Hospital, Khon Kaen University, between July and October 2024, were examined. Samples underwent Giemsa-stained blood smear microscopy and PCR amplification of the 18S rRNA gene using both primer sets. Positive amplicons were sequenced and analyzed phylogenetically using the Maximum Likelihood method. Limit of detection (LOD), sensitivity, specificity, and positive predictive value (PPV) were calculated for each primer set using sequence-confirmed results as the reference.

Results: Microscopy detected B. canis in 19/159 (11.9%) of samples, while PCR increased detection to 23/159 (14.47%). Babf/Babc detected all positive cases (100% sensitivity), while Bab7/Bab9 detected 95.65% of positives. Both primer sets achieved 100% specificity and PPV, with an equal LOD of 10⁵ DNA copies. Bab7/Bab9 also amplified Hepatozoon canis at a distinct amplicon size (503 base pair). Sequence analysis confirmed all Babesia-positive samples as B. canis vogeli, showing 96.34%-100% identity with global isolates. Phylogenetic analysis grouped the sequences with B. canis vogeli from multiple geographic regions, revealing minimal intraspecific variation.

Conclusion: B. canis vogeli was the only subspecies identified in naturally infected dogs in Khon Kaen during the study period. Babf/Babc demonstrated superior diagnostic sensitivity for B. canis vogeli, whereas Bab7/Bab9 offered broader detection, including H. canis. Phylogenetic analysis revealed close genetic relationships with isolates worldwide. These findings support the use of Babf/Babc for specific diagnosis and Bab7/Bab9 for broader screening in endemic regions.

Background and aim: Major depressive disorder is a prevalent psychiatric condition associated with impaired neuroplasticity, particularly in the hippocampus. Although selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed, their delayed onset and adverse effects highlight the need for alternative therapies. Cannabidiol (CBD), a non-psychotomimetic cannabinoid, has shown antidepressant-like properties, but its mechanistic link to hippocampal synaptic plasticity remains unclear. This study aimed to evaluate the effects of CBD on depression-like behaviors and hippocampal neuroplasticity in rats subjected to chronic restraint stress (CRS).

Materials and methods: Sixty male Wistar rats were randomly divided into six groups: Non-stressed vehicle (NV), CRS vehicle (SV), escitalopram-treated CRS (SE, 10 mg/kg), and CBD-treated CRS at 10, 30, or 100 mg/kg (SC10, SC30, and SC100). Rats were subjected to CRS for 28 days and treated daily through intraperitoneal injection. Depression-like behaviors were assessed using the forced swim test (FST) and sucrose preference test (SPT). Locomotor activity was evaluated through the open-field test (OFT). Hippocampal dendritic spine density (Golgi-Cox staining) and long-term potentiation (LTP, electrophysiology) were measured on day 28.

Results: CRS induced behavioral despair (↑ immobility in FST) and anhedonia (↓ sucrose preference in SPT), accompanied by reduced hippocampal spine density. At all doses, CBD significantly reduced immobility, comparable to escitalopram. Notably, only CBD at 100 mg/kg and escitalopram reversed anhedonia. All CBD-treated groups showed an increase in dendritic spine density, with SC10 producing the greatest enhancement. Moreover, CBD at 100 mg/kg markedly improved hippocampal LTP at 1 h and 2 h post-stimulation, an effect not observed with escitalopram. Locomotor activity remained unaffected.

Conclusion: CBD demonstrated potent antidepressant-like effects in a CRS rat model, alleviating behavioral despair and anhedonia while enhancing hippocampal dendritic spine density and synaptic strength. These findings suggest CBD as a promising candidate for stress-related mood disorders, with mechanistic actions distinct from conventional SSRIs and potential utility in patients unresponsive to current therapies.

Background and aim: Porcine epidemic diarrhea virus (PEDV) is a highly contagious enteric pathogen causing severe diarrhea and high mortality in neonatal piglets. Maternal lactogenic immunity, conveyed through colostrum and milk, is essential for protection; however, sow-derived antibodies may be insufficient in certain production systems. This study aimed to produce PEDV-specific hyperimmune colostrum and milk from goats and evaluate the safety and immunogenicity of live-attenuated and inactivated PEDV vaccines.

Materials and methods: Preliminary safety trials were performed in male goats (n = 6) to monitor clinical signs and adverse reactions after intramuscular vaccination. Ten pregnant Saanen goats were randomly assigned to two groups (n = 5 each) and immunized twice, 8 and 4 weeks before parturition, with either live-attenuated (1 × 10⁵ 50% tissue culture infectious dose [TCID₅₀]/mL) or inactivated (1 × 10⁶ TCID₅₀/mL) PEDV vaccine. Serum was collected on days 0 and 28 post-vaccination, and colostrum/milk samples were obtained on days 0, 2, 7, and 14 postpartum for virus neutralization (VN) assays. Fecal samples were analyzed using quantitative reverse transcription polymerase chain reaction to detect viral shedding.

Results: Both vaccines were well tolerated, with only transient fever observed in three goats. No severe adverse reactions occurred in pregnant goats. The live-attenuated vaccine elicited higher VN titers in serum (peak 1:32) and colostrum (peak 1:2048) compared with the inactivated vaccine (serum peak 1:16; colostrum peak 1:512). Day 0 colostrum titers were significantly greater in the live vaccine group (p = 0.028). Although titers remained higher in this group on days 2, 7, and 14, differences were not statistically significant. Viral RNA shedding was absent in the inactivated group and transient in the live group, persisting up to 7 days in one goat.

Conclusion: Vaccination of pregnant goats with live-attenuated or inactivated PEDV vaccines is safe and induces PEDV-specific antibodies in colostrum and milk. The live-attenuated vaccine generated the highest titers, indicating potential for producing goat-derived hyperimmune colostrum as an alternative passive immunization strategy for neonatal piglets. Field trials are warranted to confirm protective efficacy and explore integration into PEDV control programs.

Background and aim: Osteoarthritis (OA) is a progressive degenerative joint disorder characterized by cartilage loss, subchondral bone remodeling, and chronic pain, and remains a leading cause of disability worldwide. Although radiographic imaging and behavioral testing are widely used in preclinical research, few studies have systematically examined their interdependence. This study aimed to radiologically characterize OA progression in rats induced by monosodium iodoacetate (MIA) and to correlate structural alterations with functional and nociceptive outcomes, while exploring potential sex-specific differences and therapeutic responses to non-steroidal anti-inflammatory drugs (NSAIDs).

Materials and methods: Thirty-six Wistar rats (male and female) were divided into six experimental groups: Healthy controls, OA-induced untreated, and OA-induced meloxicam-treated. Over 28 days, animals underwent serial radiological assessments and validated behavioral tests, including weight-bearing, rotarod, and Von Frey assays. Statistical analyses employed analysis of variance with post hoc testing, ensuring methodological rigor with blinded evaluators and sex-stratified comparisons.

Results: Radiographs revealed classical OA features, joint space narrowing, subchondral bone sclerosis, and osteophyte formation, with progressive severity across timepoints. NSAID-treated males demonstrated significant improvement in motor coordination and nociceptive thresholds on days 7 and 14 (p < 0.001), whereas females exhibited only modest or delayed responses despite more severe radiological deterioration. Importantly, structural joint damage did not consistently align with behavioral impairments, underscoring a dissociation between radiographic severity and clinical-like manifestations.

Conclusion: This study provides an integrated evaluation of structural and functional outcomes in experimental OA, highlighting a complex relationship between radiological changes and behavioral impairments. The findings emphasize the necessity of multimodal assessment strategies in preclinical OA models and reveal sex-specific differences in disease progression and therapeutic response. These insights are crucial for refining translational strategies, advocating for sex-conscious approaches and combined structural-functional endpoints in OA research and drug development.