Veterinary World最新文献

Background and aim: Rabies remains a fatal zoonotic disease of major public health importance in Vietnam, with rising human and animal cases in recent years. Achieving effective control requires high vaccination coverage in dogs and cats, as well as a clear understanding of the behavioral factors influencing vaccination decisions. This cross-sectional analytical study aimed to assess vaccination coverage, examine determinants of proactive vaccination behaviors, and classify pet owners based on their knowledge, attitude, and practice (KAP) regarding rabies prevention in Duc Hue District, Long An Province, during the 2024 mass vaccination campaign.

Materials and methods: The study was conducted across 11 communes between January 10 and April 25, 2024. Data collection included a general household survey and a structured KAP questionnaire. Digital tools such as KoboToolbox, QGIS version 3.36, and RStudio version 4.5.1 were used for data entry, mapping, and statistical analysis. Logistic regression identified demographic and logistical variables associated with proactive vaccination behavior. Principal component analysis (PCA) and cluster analysis (CA) were used to classify pet owners into behavioral groups based on KAP score patterns. Ethical approval was obtained from Nong Lam University and the Long An People's Committee.

Results: A total of 6,899 of 8,776 pets were vaccinated, achieving a coverage rate of 78.6%, surpassing the national target of 70% for 2022-2025, although coverage varied widely across communes (60.63%-87.78%). Logistic regression revealed that higher education levels, specific occupations, shorter distance to veterinary services, and smaller total pet populations were significant predictors of proactive vaccination behavior. PCA and CA identified three distinct groups of pet owners. The group with higher education levels and farming occupations demonstrated the strongest KAP profile, while the lowest-performing group was associated with limited education and greater logistical challenges in accessing veterinary services.

Conclusion: This study presents the first integrated behavioral-statistical classification of pet owners in southern Vietnam using PCA and clustering, providing a data-driven foundation for more targeted rabies vaccination interventions. Addressing logistical barriers, improving equitable access to veterinary services, and tailoring educational activities toward low-performing groups are essential for sustaining vaccination gains and advancing Vietnam's goal of achieving 80% coverage by 2030.

Background and aim: Highly pathogenic avian influenza (HPAI) remains a global threat to poultry production, trade, and public health. While Morocco has not yet reported confirmed HPAI outbreaks, the endemic circulation of low-pathogenic avian influenza (LPAI) H9N2 since 2016, proximity to affected neighboring countries, and Morocco's position along migratory bird flyways highlight the country's vulnerability. This study aimed to identify high-risk areas for HPAI introduction and spread to inform risk-based surveillance and control policies.

Materials and methods: We applied a spatial multi-criteria decision analysis integrated with geographic information systems at the provincial scale. Relevant risk factors were identified through a literature review and expert consultation, and categorized into the introduction (wetlands, live poultry imports, recreational bird imports, and poultry products) and spread (poultry density and type, live bird markets, transport networks, and human population density) domains. Weights were assigned to factors using the analytic hierarchy process based on responses from 73 poultry-sector experts. Data were normalized, integrated into composite risk maps, and validated against historical LPAI H9N2 outbreak data (2016). Sensitivity and uncertainty analyses were used to assess model robustness.

Results: The final maps revealed that 25 provinces (33.3% of the national territory) exhibited high-to-very high risk of HPAI introduction, particularly along northern coastal provinces, border regions, and areas linked to recreational bird imports. For spread risk, 41 provinces (41.3%) were classified as high to very high, concentrated in the Casablanca-Settat, Rabat-Salé-Kenitra, Fès-Meknès, and Marrakech-Safi regions, which are characterized by dense poultry production, major trade hubs, and extensive transport networks. Sensitivity analyses confirmed the model's stability, with variations in weight producing a minimal impact on risk classifications.

Conclusion: This study provides the first comprehensive spatial risk maps of HPAI introduction and spread in Morocco, highlighting priority provinces for early detection, targeted surveillance, and preventive biosecurity measures. Despite limitations arising from reliance on LPAI data and expert judgment, the approach offers a robust decision-support tool for veterinary authorities. The methodology is adaptable to regional applications and can be refined with real-time surveillance data, enhancing Morocco's preparedness and resilience against future avian influenza incursions.

Background and aim: Palmitic acid (PA) (C16: 0) is a rumen-inert long-chain fatty acid (FA) widely used in dairy cattle to increase dietary energy density and milk fat synthesis; however, its effects in dairy goats remain poorly characterized. This study evaluated whether supplementing 3% or 6% PA in the diet of mid-lactation goats could improve milk yield, composition, FA profile, and whole-animal energy balance under semi-arid Mexican production conditions.

Materials and methods: Twenty-one multiparous crossbred goats (45.8 ± 1.2 kg; 21 ± 3 days in milk) were randomly assigned to three treatments for 6 weeks after a 2-week adaptation: (1) Control diet (without PA), (2) diet + 3% PA, and (3) diet + 6% PA on a dry-matter (DM) basis. Diets were isoenergetic and isoproteic before PA addition. Individual DM intake (DMI), milk yield, and composition were measured daily; milk FA profiles and energy balance were determined on days 0, 21, and 42. Data were analyzed using a mixed-model with repeated measures, and means were compared using the Tukey test (p ≤ 0.05).

Results: PA inclusion did not affect DMI, body weight, or milk yield. However, milk fat concentration and yield increased significantly (p < 0.01) in both PA treatments, with the highest fat concentration observed at 6% PA. The milk FA profile shifted toward greater C16: 0 and C16: 1 proportion (p < 0.0001) and decreased short-chain (C16) FA fractions. Energy-corrected milk yield rose by ~40% in PA-fed goats, and energy balance improved markedly from week 3 onward, particularly in the 3% group (p < 0.01), indicating superior dietary energy utilization without intake suppression.

Conclusion: Moderate PA supplementation (~3% DM) effectively enhances milk fat synthesis and energy efficiency in goats while maintaining stable intake and yield. Increasing PA beyond 3% confers minimal additional benefit and may overly saturate milk fat. These findings provide species-specific evidence that rumen-inert fat inclusion can be an efficient strategy to support metabolic status and product quality in mid-lactation goats under variable forage systems.

Background and aim: An increased proportion of female piglets is desirable in commercial swine breeding to improve productivity, facilitate genetic selection, and reduce the need for male castration. However, currently available sex-selection techniques, such as flow cytometry, are costly and impractical for routine field use. This study evaluated the potential of rabbit serum albumin (RSA) as a low-cost biochemical modulator to influence the proportion of female offspring, comparing its effects with those of other albumin sources and determining optimal supplementation conditions for boar semen used for artificial insemination (AI).

Materials and methods: Eight Landrace boars were initially screened in vitro to assess sperm quality and the proportion of X- and Y-bearing sperm following incubation with albumin. Four boars (A, B, E, and G) showing a higher X-sperm proportion were subsequently selected for in vivo trials involving 130 sows. Semen was diluted in a conventional extender supplemented with albumin (RSA, porcine serum albumin, or bovine serum albumin) or left unsupplemented (control). The effects of albumin source, concentration (0.1-0.2 mg/mL), incubation temperature (25°C vs. 37°C), duration (5-15 min), and boar variation were examined. Offspring sex ratio and litter size were analyzed using the Kruskal-Wallis test, followed by Dwass-Steel-Critchlow-Fligner pairwise comparisons (p < 0.05).

Results: All albumin treatments significantly increased (p < 0.05) the proportion of female piglets compared with controls. RSA yielded the greatest effect, particularly at 0.1 mg/mL incubated at 37°C for 15 min, producing up to 61.8% female offspring compared with 24.8% in controls. Boars with an initial male-biased sex ratio showed the largest improvement after RSA treatment. Although litter size decreased slightly with albumin supplementation, the difference was not statistically significant (p ≥ 0.05).

Conclusion: Supplementation of semen extenders with RSA effectively increased the proportion of female piglets without compromising fertility. This method offers a practical, scalable, and economical alternative to conventional sex-sorting technologies for swine breeding. Further optimization and larger-scale validation are warranted to ensure consistent litter performance and broader adoption in commercial production systems.

Background and aim: Canine monocytic ehrlichiosis, caused by Ehrlichia canis and transmitted primarily by Rhipicephalus sanguineus, is a common yet diagnostically challenging tick-borne disease in tropical regions. On the northern coast of Perú, environmental conditions favor vector persistence, but local data on clinical characteristics and risk determinants remain limited. This study aimed to determine the seroprevalence of E. canis in domestic dogs in Trujillo (La Libertad, Perú), describe associated clinical findings, and identify epidemiological risk factors linked to infection.

Materials and methods: A cross-sectional analytical study was conducted from December 2023 to August 2024 involving 462 dogs with compatible clinical signs and/or tick infestation from 18 veterinary clinics across three districts. Serological testing was performed with the CaniV-4® rapid test, and hematological parameters were analyzed with an automated analyzer. Epidemiological data were obtained through owner questionnaires. Associations were evaluated using chi-square tests, logistic regression (Odds ratio [OR], 95% CI), and Mann-Whitney U tests for hematological differences. A p-value < 0.05 with OR and lower CI >1 defined risk factors.

Results: The overall seroprevalence of E. canis was 51.3% (95% CI: 46.7%-55.8%). Sex and breed were not associated with infection. Dogs <1 year old (OR = 1.46), those lacking external deworming (OR = 1.99), fed homemade diets (OR = 2.26), and those frequently contacting stray dogs (OR = 4.33) were at significantly higher risk. Clinical predictors strongly associated with infection included lethargy (OR = 5.55), fever (OR = 5.52), anorexia (OR = 4.24), anemia (OR = 4.12), lymphadenopathy (OR = 3.46), and epistaxis (OR = 2.50). Seropositive dogs exhibited significantly reduced erythrocyte counts, hematocrit, hemoglobin, leukocyte counts, and platelet counts (p < 0.01). Although tick presence and park access were associated with seropositivity, their OR < 1 suggested confounding rather than true protective effects.

Conclusion: The high seroprevalence and significant clinical-hematological alterations highlight widespread exposure to E. canis among dogs in northern coastal Perú. Identified risk factors emphasize the need for integrated tick-control, improved owner awareness, and strengthened diagnostic protocols. Future research combining molecular confirmation, socioeconomic variables, and One Health-based surveillance is recommended to refine prevention and management strategies.

Background and aim: Aeromonas hydrophila is a zoonotic, antimicrobial-resistant pathogen that causes significant losses in aquaculture and raises important One Health concerns. Outer membrane protein (OMP)-based subunit vaccines provide a targeted, antibiotic-sparing alternative to traditional bacterins, but validation across mammalian species remains limited. This study assessed the immunogenicity, safety, and protective effectiveness of a native ~34 kDa Omp34 (nOmp34) subunit vaccine in BALB/c mice, comparing it to a formalin-killed cell (FKC) vaccine, and examined immune factors that may predict survival.

Materials and methods: Female BALB/c mice (n = 13 per group) received subcutaneous injections of phosphate-buffered saline (PBS), FKC, FKC + incomplete Freund's adjuvant (IFA), or native Omp34 + IFA on days 0, 14, and 28. Immune responses were assessed by measuring anti-Omp34 immunoglobulin (Ig)G2a levels via enzyme-linked immunosorbent assay, serum lysozyme activity, nitroblue tetrazolium (NBT) respiratory burst, and phagocytic activity at specified intervals up to day 42. On day 42, mice were challenged intraperitoneally with a lethal dose of A. hydrophila, causing 80% mortality, and observed for 14 days for survival, clinical scores, and body weight changes. Data analysis involved analysis of variance with Tukey post hoc tests, mixed-effects modeling, Spearman correlation, receiver operating characteristic curves, logistic regression, and Kaplan-Meier survival analysis.

Results: By day 42, all immune biomarkers showed clear separation (nOmp34+IFA > FKC + IFA > PBS; p < 0.05). NBT demonstrated the strongest correlation with survival (ρ ≈ 0.90) and the highest predictive performance (Area under the curve [AUC] ≈ 0.80), exceeding IgG2a and phagocytosis (AUC ≈ 0.70). Post-challenge survival rates were 84.6% for nOmp34 + IFA, 61.5% for FKC + IFA, and 23.1% for PBS, corresponding to relative percent survival values of 80% and 50% compared to PBS. The direct comparison between nOmp34 and FKC revealed a favorable but not statistically significant survival benefit (p = 0.238). Vaccination was well-tolerated, with stable body weight, minimal reactogenicity, and no severe clinical events.

Conclusion: The nOmp34 subunit vaccine elicited a strong, coordinated humoral and innate immune response, surpassing the matched bacterin in both efficacy and immune strength. NBT activity between days 35-42 proved to be a practical indicator of protection, aligning mechanistically with nicotinamide adenine dinucleotide phosphate -oxidase-mediated bacterial killing. These findings offer proof-of-concept for Omp34 as a scalable, antibiotic-sparing vaccine candidate and support its progression into aquaculture-relevant platforms within a One Health framework.

Viral infections continue to pose major challenges to pig health, farm productivity, and global food security. Early and accurate diagnosis is the cornerstone of disease prevention, surveillance, and control in swine populations. In recent years, remarkable progress has been achieved in molecular, serological, and digital diagnostic technologies, enabling more rapid, sensitive, and field-adaptable detection of important porcine viruses such as African swine fever virus, porcine reproductive and respiratory syndrome virus, and classical swine fever virus. This review summarizes current and emerging diagnostic approaches, highlighting polymerase chain reaction (PCR) and its advanced forms, quantitative PCR and digital PCR, as the gold standards for laboratory confirmation. The advent of next-generation sequencing and metagenomics has revolutionized pathogen discovery and genomic surveillance, providing comprehensive insights into viral evolution and transboundary transmission. Isothermal amplification techniques such as loop-mediated isothermal amplification and recombinase polymerase amplification have shown strong potential for on-farm diagnosis due to their simplicity, rapidity, and minimal equipment requirements. Innovations such as clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated-based assays, biosensors, lab-on-a-chip platforms, and point-of-care testing devices are bridging the gap between laboratory precision and field application, allowing rapid decision-making during outbreaks. The integration of artificial intelligence, machine learning, and geographic information systems has further enhanced diagnostic interpretation, real-time data sharing, and early outbreak prediction under the One Health framework. Despite these advances, challenges remain in ensuring assay standardization, affordability, and equitable access in resource-limited regions. Continued international collaboration, data sharing, and policy harmonization under the guidance of the Food and Agriculture Organization, the World Organization for Animal Health, and the World Health Organization are essential for the global control of swine viral diseases. Ultimately, combining molecular innovation with digital adaptability offers the most promising path toward resilient, cost-effective, and sustainable diagnostic systems for safeguarding animal and public health.

Background and aim: The rapid rise of antimicrobial resistance threatens effective infection control and reinforces the need for alternative therapeutics. Chromolaena odorata (Siam weed), a traditionally used medicinal plant rich in phenolic and flavonoid compounds, has been reported to possess antimicrobial properties. This study evaluated the antimicrobial, antibiofilm, antioxidant, and ultrastructural effects of ethanolic C. odorata leaf extract against a diverse panel of Gram-positive and Gram-negative bacteria.

Materials and methods: Ethanolic crude extract was prepared from dried C. odorata leaves, and its antimicrobial activity was assessed against 46 bacterial isolates using disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Total phenolic and flavonoid contents were quantified using Folin-Ciocalteu and aluminum chloride methods. Antioxidant activity was measured using the 2,2-diphenyl picrylhydrazyl (DPPH) radical scavenging assay. Antibiofilm efficacy against Bacillus cereus was determined using crystal violet staining at sub-MIC levels. Ultrastructural alterations in B. cereus were examined via scanning electron microscopy (SEM).

Results: The crude extract inhibited 78.26% (36/46) of tested isolates, with strong activity against nine species, including B. cereus, Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Aeromonas hydrophila, Stenotrophomonas maltophilia, Citrobacter freundii, and Shigella sonnei. MIC values ranged from 31.25-125 mg/mL, with B. cereus showing the lowest MIC and MBC (31.25 mg/mL). The extract exhibited high phenolic (96.82 ± 2.07 μg Gallat-equivalents/mg) and flavonoid (62.98 ± 2.64 μg Quercetin equivalent /mg) content, and moderate antioxidant activity (IC₅₀ = 120.02 ± 16.31 μg/mL). Sub-MIC concentrations significantly inhibited B. cereus biofilm formation in a dose- and time-dependent manner, achieving up to 66.16% inhibition at 1/2 MIC after 72 h (p < 0.001). SEM analysis revealed cell shrinkage, wall collapse, and surface roughening in treated B. cereus, indicating disrupted cell integrity.

Conclusion: Ethanolic C. odorata extract demonstrates broad-spectrum antibacterial, antibiofilm, antioxidant, and cell-disruptive activities, with pronounced effects against B. cereus. These findings highlight its potential as a natural antimicrobial or disinfectant candidate and support future development of plant-based agents to mitigate resistant bacterial infections.

Background and aim: Biofilm-forming Aeromonas hydrophila represents a critical constraint in aquaculture, driving recurrent infections, environmental persistence, and antimicrobial resistance. Sustainable alternatives to antibiotics are urgently needed. This study evaluated the multiphase antibiofilm activity of chitosan nanoparticles (ChNPs) synthesized from Litopenaeus vannamei shrimp shells against clinical A. hydrophila isolates from Indonesian gourami (Osphronemus gouramy), focusing on their effects during biofilm adhesion, planktonic proliferation, and mature biofilm degradation.

Materials and methods: Between February 2024 and March 2025, diseased gourami were sampled from aquaculture sites in Surabaya, Indonesia. Three wild-type A. hydrophila isolates (A1G1, A2G1, A3G1) were confirmed via biochemical and 16S rRNA sequencing. ChNPs were synthesized through ionic gelation of deacetylated chitosan with sodium tripolyphosphate and characterized by Scanning Electron Microscopy (SEM), dynamic light scattering, and Fourier Transform Infrared Spectroscopy (FTIR) analyses. Antibiofilm efficacy was tested at concentrations of 15-45 µg mL^-¹ using crystal violet staining (optical density [OD]₅₉₅) for adhesion and degradation phases, and turbidity (OD₆₀₀) for planktonic inhibition. Data were analyzed using one- and two-way analysis of variance with Tukey's post hoc test.

Results: ChNPs exhibited spherical morphology (≈641 nm; ζ = +51 mV) and stable ionic crosslinking. They significantly inhibited adherent biomass formation (p < 0.05), reducing OD₅₉₅ from 0.787 to 0.317 in the most responsive strain A3G1 (> 59 % inhibition). Planktonic growth (OD₆₀₀) declined dose-dependently (63 % inhibition at 45 µg mL^-¹), with significant strain-concentration interactions (p < 0.01). Mature biofilm degradation reached 63% at 45 µg mL^-¹, approaching the level of the antibiotic-treated control. SEM and FTIR data supported electrostatic disruption and extracellular polymeric substance penetration as probable mechanisms.

Conclusion: Shrimp-shell-derived ChNPs effectively suppressed A. hydrophila biofilms at multiple developmental stages, demonstrating a potent, biodegradable alternative for the control of aquaculture pathogens. Their integration into eco-friendly, antibiotic-free disease management aligns with circular bioeconomy and One Health frameworks. Further in vivo validation and formulation optimization are warranted.

Background and aim: General anesthesia (GA) suppresses the blink reflex and lacrimal gland activity, making animals more vulnerable to precorneal tear film (PTF) issues. Although decreases in tear volume during GA are well documented, changes in PTF quality are not well understood. This study examined both the quantity and quality of PTF, including the Schirmer Tear Test-1 (STT-1), tear osmolarity (TO), tear ferning (TF), and punctate fluorescein staining (PFS), in healthy mesocephalic Canis familiaris undergoing routine non-ophthalmic surgery under GA.

Materials and methods: A prospective, randomized, pre-post study was conducted on 16 client-owned mesocephalic dogs (32 eyes). All subjects were clinically and ophthalmologically normal and classified as American Society of Anesthesiologists (ASA) I-II. Tear film parameters were evaluated at five perioperative time points: 30 min preoperatively (T0), 10 min post-premedication (T10), 5 min post-induction (T5), at first surgical incision (TS), and at discharge (TD). STT-1, TF, and TO were measured at each time point; PFS was performed at TD. GA consisted of methadone and dexmedetomidine premedication, propofol induction, and isoflurane maintenance. Mixed-effects regression, paired t-tests, and correlation analyses were applied, with p < 0.05 considered significant.

Results: STT-1 values significantly decreased from baseline (21.2 ± 3.3 mm/min) to T10 (13.5 ± 5.9 mm/min; p < 0.001), T5 (6.4 ± 6.3 mm/min; p < 0.001), and TS (0.8 ± 1.6 mm/min; p < 0.001). TO decreased from 374.4 ± 29.3 mOsm/L at T0 to 354.7 ± 28.2 mOsm/L at TS (p < 0.001). TF grades increased from 0.8 ± 1.0 at T0 to 1.5 ± 1.3 at T10 and 2.3 ± 1.4 at T5 (p < 0.001), indicating deterioration of PTF structure. Moderate correlations were observed among STT-1, TF, and TO. At TD, tear parameters remained significantly altered compared with T0, and PFS identified punctate epithelial lesions in 34.4% of dogs. Age showed a moderate negative relationship with STT-1 (b = -0.41 mm/min; p = 0.038).

Conclusion: GA causes a significant decline in the quantity and quality of the PTF, with incomplete recovery by discharge despite the return of spontaneous blinking. These findings emphasize the need for proactive perioperative ocular surface protection and highlight TF and TO as useful early indicators of anesthesia-related ocular surface impairment in mesocephalic Canis familiaris.