Veterinary World最新文献

Background and aim: Citronella straw (Cymbopogon nardus L.), a byproduct of essential oil extraction, is rich in lignin therefore poorly digestible, which limits its use as livestock feed. This study examined the impact of ammoniation and fungal fermentation using Pleurotus ostreatus, Trichoderma harzianum, and Aspergillus niger on the nutritional value, digestibility, and palatability of citronella straw for ruminants.

Materials and methods: Six treatments were evaluated in vitro with five replications: Ammoniated citronella straw (CsA), citronella straw fermented with P. ostreatus (CsFP), citronella straw fermented with A. niger, ammoniated and fermented with T. harzianum (CsAFTh), ammoniated and fermented with P. ostreatus (CsAFP), and ammoniated and fermented with A. niger. Samples were analyzed for proximate composition, fiber fractions, phenolic content, in vitro digestibility, and rumen fermentation parameters (pH, ammonia, volatile fatty acids, and methane). Palatability of selected treatments (CsAFTh vs. CsAFP) was tested in 18 Ettawa goats (18 months; 22.4 ± 5.5 kg).

Results: The CsAFP significantly enhanced nutritive value, reducing acid detergent fiber (63.3% in CsA to 53.9%) and acid detergent lignin (15.7% in CsA to 11.4%), while increasing crude protein (9.1% vs. 6.4%-8.4%). Dry matter digestibility improved by 10%-12% (p < 0.0001). Rumen fermentation showed increased propionate, reduced acetate: propionate ratio, and CH₄ reduction of 0.5 mmol/L. Palatability testing revealed higher voluntary feed intake for CsAFP (98 g at 360 min) compared with CsAFTh (36 g).

Conclusion: CsAFP most effectively improved the nutritional quality, digestibility, and palatability of citronella straw. This strategy reduces lignin, enhances fiber utilization, shifts fermentation toward propionate, and decreases CH₄ emission, supporting its potential as a sustainable feed for smallholder ruminant production. Further in vivo studies are warranted to confirm long-term performance, safety, and field applicability.

Background and aim: Canine distemper virus (CDV) remains a major cause of morbidity and mortality in dogs worldwide, particularly in unvaccinated populations. Current therapeutic options are largely supportive, with no widely available effective antiviral treatment. Nanotechnology-based therapies, such as copper nanoparticles (CuNPs), have recently shown promise against a range of viral pathogens. This study aimed to evaluate the clinical efficacy and safety of CuNPs in naturally infected dogs with CDV and to assess their effects on hematological and biochemical parameters.

Materials and methods: A total of 28 mixed-breed dogs (aged 2-8 months) were enrolled between January and February 2024. Clinical suspicion of CDV was confirmed by rapid immunochromatographic testing and reverse transcription polymerase chain reaction (RT-PCR) targeting the N gene. Fifteen CDV-positive dogs received oral CuNPs (0.5 mg/kg, twice daily for 5 days), while five untreated CDV-positive dogs served as controls; five healthy dogs were also included as negative controls. Hematological and biochemical parameters were monitored before and after treatment. CuNPs were characterized by ultraviolet-visible spectroscopy, scanning electron microscopy, and zeta potential analysis.

Results: CDV was detected in 65% (15/23) of clinically suspected dogs by RT-PCR. Treated dogs demonstrated marked improvement in clinical signs, with complete recovery in all non-neurological cases and a 75% recovery rate in neurological cases. Hematological analyses revealed significant increases (p < 0.05) in red blood cell count, hemoglobin, packed cell volume, platelet count, white blood cell count, and lymphocyte count in CuNP-treated dogs compared with untreated controls. Serum biochemistry showed reductions in alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, blood urea nitrogen, and creatinine, alongside improved albumin levels after treatment. No adverse effects were observed during or after therapy.

Conclusion: CuNPs demonstrated significant antiviral activity and clinical benefit in dogs naturally infected with CDV. The findings suggest that CuNPs may represent a promising adjunctive therapy for canine distemper. However, larger controlled trials are warranted to validate efficacy, optimize dosing, and ensure long-term safety.

Bluetongue (BT) is an economically important viral disease of domestic and wild ruminants, caused by the bluetongue virus (BTV), and transmitted primarily by Culicoides midges. The virus has at least 28 known serotypes and several emerging strains, with its distribution expanding beyond traditional endemic zones due to climate change and global trade. This review summarizes recent developments in the epidemiology, molecular characterization, diagnostics, vaccines, and control of BT, with an emphasis on its implications within the One Health framework. A comprehensive literature search covering studies from 2000 to 2025 revealed significant outbreaks in Europe (2024-2025) involving BTV-3 and BTV-12, as well as the emergence of novel serotypes in Asia and Africa. Global economic losses exceed USD 3 billion annually due to mortality, production losses, and trade restrictions. Advances in molecular diagnostics, such as reverse transcription polymerase chain reaction, whole-genome sequencing, and rapid field assays like loop-mediated isothermal amplification and clustered regularly interspaced short palindromic repeats -based platforms, have improved surveillance and serotype identification. Although vaccination remains the cornerstone of BT control, current live and inactivated vaccines are limited by serotype specificity and reassortment risks, highlighting the need for new-generation virus-like particle, recombinant, DNA, and mRNA-based vaccines. Persistent challenges include the absence of differentiating infected from vaccinated animals -compatible polyvalent vaccines, incomplete knowledge of wildlife reservoirs, and uneven surveillance capacities worldwide. Strengthening integrated vector management, genomic monitoring, and climate-informed control strategies through a coordinated One Health approach will be vital to reduce the global burden of bluetongue.

Background and aim: Non-typhoidal Salmonella (NTS) is a leading cause of foodborne illness, with poultry products serving as major transmission routes. In sub-Saharan Africa, surveillance of antimicrobial resistance (AMR) and virulence determinants remains limited. This study investigated the prevalence, AMR, and virulence gene profiles of NTS isolated from poultry products retailed in Arusha, Tanzania.

Materials and methods: A cross-sectional study was conducted between August and October 2023. A total of 240 samples (layer eggs and broiler meat) were collected from two wards in Arusha City using systematic random sampling. NTS isolates were confirmed by polymerase chain reaction (PCR) and tested for susceptibility to 11 antimicrobial agents using the Kirby-Bauer method. Virulence (invA and stn) and resistance genes (tetA, tetB, bla_TEM, bla_CTXM , and bla_SHV ) were screened by PCR. Statistical associations were analyzed using odds ratios (OR) and 95% confidence intervals (CI).

Results: The overall prevalence of NTS was 23.3% (56/240). Layer eggs showed significantly higher contamination (20%) compared with broiler meat (3.3%) (OR = 10.0, 95% CI: 4.4-22.6, p < 0.001). Salmonella Typhimurium was the predominant serotype. All isolates carried invA and stn genes. Alarmingly, 100% of isolates were resistant to imipenem (IMI), while resistance to ampicillin (58.9%) and tetracycline (41.1%) was also common. Multidrug resistance patterns were frequent, although resistance genes were detected at a low prevalence (tetA, 5.3%; bla_TEM , 3.5%).

Conclusion: The findings demonstrate a high prevalence of virulent and IMI-resistant S. Typhimurium in retail poultry products in Arusha, particularly in eggs. These results highlight critical gaps in food safety regulation and antimicrobial stewardship within the Tanzanian One Health framework. Further genomic studies are warranted to elucidate underlying resistance mechanisms and inform effective surveillance strategies.

Background and aim: Antimicrobial resistance (AMR) has emerged as a global health threat, with food-producing animals recognized as reservoirs of multidrug-resistant (MDR) bacteria. Guinea pigs (Cavia porcellus), traditionally consumed in several Andean regions, remain underexplored in terms of food safety risks. This study aimed to detect, characterize, and analyze the AMR patterns and resistance genes of Klebsiella spp. and Enterobacter spp. isolated from slaughtered guinea pigs intended for human consumption in Colombia.

Materials and methods: A cross-sectional descriptive study was conducted on 70 guinea pigs with macroscopic intestinal lesions. Intestinal swabs were cultured on blood and MacConkey agar, and isolates were identified using biochemical tests and 16S ribosomal RNA sequencing. Antimicrobial susceptibility testing was performed against nine antibiotics representing seven antimicrobial classes, using Clinical and Laboratory Standards Institute standards. MDR was defined as resistance to ≥1 antibiotic in ≥3 classes. Polymerase chain reaction assays were employed to detect resistance genes, including β-lactamase Klebsiella pneumoniae carbapenemase (bla_KPC ), class d β-lactamase oxacillinase-48 gene (bla_OXA-48 ), ampC-lactamase (ampC), and New Delhi metallo-beta-lactamase 1 (bla_NDM-1 ).

Results: Ten isolates were obtained, comprising Klebsiella spp. (70%) and Enterobacter hormaechei (30%). All isolates (100%) exhibited MDR profiles. High resistance rates were observed against fluoroquinolones (100%), beta-lactams (90%), aminoglycosides (70%), carbapenems (70%), and cephalosporins (70%), whereas resistance to trimethoprim-sulfamethoxazole was 40%. Molecular analysis revealed the presence of bla_KPC in seven isolates, bla_OXA-48 in two, and ampC in three. No bla_NDM-1 genes were detected. Notably, E. hormaechei isolates demonstrated broader resistance spectra than Klebsiella.

Conclusion: This study provides the first evidence in Colombia of MDR Klebsiella spp. and Enterobacter spp. isolates carrying clinically important resistance genes in guinea pigs intended for human consumption. The detection of carbapenemase genes (bla_KPC and bla_OXA-48 ) is particularly concerning given their role in limiting therapeutic options. These findings highlight the urgent need for improved antimicrobial stewardship, stricter regulation of antibiotic use in guinea pig production systems, enhanced surveillance, and targeted farmer education to mitigate AMR risks at the human-animal interface.

Background and aim: Escherichia coli strains producing Shiga toxins (stx1, stx2) are important zoonotic pathogens. Wild rats, common in urban environments with poor sanitation, may act as reservoirs and contribute to environmental contamination. This study aimed to detect Shiga toxin-producing E. coli (STEC) in wild rats captured from slum-adjacent urban areas of Banyuwangi District, Indonesia.

Materials and methods: From August to October 2024, a total of 100 wild rats (32% Rattus norvegicus, 68% Rattus tanezumi) were trapped in Kampung Mandar and Lateng Villages. Rectal swabs were collected and cultured on eosin methylene blue agar, followed by biochemical and sugar fermentation tests for preliminary identification. Molecular confirmation of E. coli was performed using a polymerase chain reaction (PCR) targeting cydA and lacY. Confirmed isolates were further screened for stx1 and stx2 genes. Statistical analysis was performed using Chi-square tests.

Results: PCR confirmed E. coli in 57% (57/100) of rats. Among these, 47.36% (27/57) carried the stx1 gene, 7.01% (4/57) carried the stx2 gene, and 3.51% (2/57) harbored both genes. The prevalence of E. coli was significantly higher in R. tanezumi than in R. norvegicus (p = 0.000), but toxin gene distribution showed no significant differences across species, sex, or locations.

Conclusion: This study provides the first molecular evidence of wild rats in Banyuwangi carrying E. coli strains harboring stx1 and stx2 genes. The findings highlight the role of urban rodents as reservoirs of zoonotic STEC and underline the need for routine monitoring, improved waste management, and integrated One Health strategies to mitigate zoonotic transmission risks in high-density urban environments.

Background and aim: Cytology is a minimally invasive, rapid, and cost-effective diagnostic tool widely used in veterinary medicine for evaluating a broad range of lesions. While extensively applied in clinical practice, large-scale epidemiological analyses of cytologic findings in canine populations are limited. This study aimed to evaluate the diagnostic performance of cytology in dogs in Portugal, assessing associations between lesion type, anatomical location, and demographic factors, and to identify patterns that can improve diagnostic utility in veterinary practice.

Materials and methods: A retrospective analysis was conducted on 12,671 cytological samples collected from canine patients between January 2010 and December 2016, submitted by 355 veterinary practices across mainland Portugal. Samples were categorized by anatomical location and diagnostic classification (neoplastic, inflammatory, non-neoplastic/non-inflammatory, and other). Demographic variables (sex, age, and breed) were recorded. Statistical analyses included non-parametric tests, logistic regression, and trend analyses to explore associations between diagnostic outcomes and study variables.

Results: The overall diagnostic yield was 69.03%, with the highest rates in fluid (80.21%), mucosal (77.08%), and glandular (75.78%) samples. Cutaneous/subcutaneous lesions, although the most frequent, had the lowest diagnostic yield (66.12%). Of diagnostic cases, 43.94% were neoplastic, with prevalence increasing significantly with age, from 17.75% in dogs ≤1 year to 54.75% in those >10-15 years (p < 0.001). Females were more likely to present epithelial and mesenchymal lesions, while males more frequently had round cell and melanocytic lesions. Breed analysis revealed no significant predispositions after statistical adjustment. Veterinary hospitals achieved higher diagnostic rates than clinics (p = 0.002). Non-diagnostic samples (30.97%) were primarily attributed to poor sample quality or insufficient cellularity.

Conclusion: Cytology is a valuable first-line diagnostic modality in canine veterinary practice, particularly effective for fluid, mucosal, and glandular lesions. Lesion prevalence varies significantly with age and sex, highlighting the need for tailored diagnostic considerations. Standardizing sample collection and preparation techniques, especially for anatomical sites with lower yields, could further improve diagnostic accuracy. While the absence of histopathological confirmation limits definitive classification, the large dataset and standardized diagnostic review strengthen the reliability of findings. Integrating cytology into routine diagnostics can enhance early disease detection, guide treatment decisions, and support epidemiological surveillance.

Background and aim: Manganese (Mn) is an essential trace mineral for poultry, supporting skeletal development, metabolism, and intestinal health. Conventional inorganic Mn sources often have low bioavailability, leading to oversupplementation, environmental excretion, and mineral imbalance. Mn nanoparticles (Mn-NP) offer improved absorption and reduced environmental burden, but their graded effects on broiler growth, intestinal morphology, meat quality, and tight junction proteins remain underexplored. This study evaluated the impact of dietary Mn-NP supplementation on productive performance, serum metabolites, jejunal architecture, and intestinal barrier function in broilers.

Materials and methods: A total of 240-day-old broiler chicks were randomly assigned to six groups (n = 40; 4 replicates of 10 birds) and fed a basal diet (control), bulk Mn (80 mg/kg), or Mn-NP at 20, 40, 60, or 80 mg/kg for 35 days. Growth performance, visceral organ development, serum biochemistry, meat physicochemical attributes, jejunal morphology, and messenger RNA expression of claudin-5 (CLDN-5) and zonula occludens-1 (ZO-1) were evaluated.

Results: Mn-NP supplementation did not significantly alter body weight or feed intake. However, the 40-Mn-NP group showed improved feed conversion ratio during weeks 2 and 3 compared with the 80-Mn-NP group. The gizzard weight decreased significantly at 40-Mn-NP, while bulk Mn increased cecal weight. Serum metabolites, including liver and kidney markers, remained unaffected across treatments, indicating no toxicity. Muscle pH45min was higher in 20- and 40-Mn-NP groups, while pH24 was reduced in the 40-Mn-NP and bulk Mn groups. Birds supplemented with 80-Mn-NP exhibited larger muscle fibers, whereas the 20-Mn-NP group showed higher fiber density. Jejunal villi were longer and crypts deeper in the 20-Mn-NP group, while tight junction proteins (CLDN-5, ZO-1) were significantly upregulated in the 60-Mn-NP group.

Conclusion: Mn-NP supplementation at 40-60 mg/kg optimally enhanced feed efficiency, jejunal morphology, and intestinal barrier integrity without adverse health effects. These findings highlight Mn-NP as a sustainable alternative to conventional Mn supplementation, improving gut health and meat quality while reducing mineral excretion. Future studies should validate long-term safety and commercial-scale applications.

Background and aim: Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide widely implicated in stress responses, appetite regulation, and emotional behavior. While PACAP has been linked to stress-induced appetite suppression, its role in circadian feeding and stress-related hyperphagia remains poorly defined. This study aimed to clarify the contribution of PACAP to circadian feeding behavior, chronic stress-induced hyperphagia, and emotional regulation in mice.

Materials and methods: Experiments were conducted using PACAP knockout (KO) and wild-type (WT) CD-1 mice. Acute and chronic restraint stress paradigms were applied, and food intake, body weight, and behavioral assays were recorded. Viral-mediated PACAP overexpression in the ventromedial hypothalamus (VMH) was performed using adeno-associated vectors. Emotional regulation was assessed through forced swim and tail suspension tests (TSTs). PAC1 receptor expression was quantified by reverse transcription and quantitative polymerase chain reaction.

Results: PACAP overexpression in the VMH significantly increased nocturnal feeding, demonstrating a circadian-specific effect on appetite regulation. Chronic restraint stress enhanced food intake in both PACAP KO and WT mice, whereas acute stress showed no effect, indicating that chronic stress-induced hyperphagia occurs independently of PACAP signaling. Behaviorally, PACAP-overexpressing mice exhibited reduced immobility in forced swim and TSTs, consistent with enhanced stress resilience and antidepressant-like effects. Importantly, PAC1 receptor expression remained stable throughout the diurnal cycle, suggesting that PACAP's modulatory effects are driven by neuropeptide availability rather than receptor fluctuations.

Conclusion: This study identifies PACAP in the VMH as a key modulator of circadian feeding and emotional behavior, while demonstrating its non-essential role in chronic stress-induced hyperphagia. The findings suggest that PACAP selectively integrates circadian and emotional signals to regulate feeding, independent of compensatory neuropeptide systems that mediate stress hyperphagia. These insights advance the understanding of neuropeptide regulation of energy balance and mood, with implications for stress-related eating disorders and anxiety.

Background and aim: Trichinellosis, a major zoonotic foodborne disease caused by Trichinella spp., remains challenging to diagnose in its early stages due to low antibody titers and limitations of conventional excretory-secretory (ES) antigens. Recombinant antigens, particularly serine proteases expressed throughout infection, represent promising candidates for specific and sensitive diagnostics. This study aimed to clone, express, and evaluate recombinant serine proteases from Trichinella spiralis (rTsp-LE) to Trichinella nativa (rTnsp-4E), and to assess their diagnostic performance compared with ES antigens and a commercial kit.

Materials and methods: Serine protease genes of T. spiralis and T. nativa were amplified, cloned into pET28c+ vectors, expressed in Escherichia coli, and purified under denaturing conditions. Antigenicity was tested by immunoblotting and an indirect enzyme-linked immunosorbent assay using sera from experimentally infected rabbits, naturally infected pigs, and immunized BALB/c mice. Antibody dynamics were monitored over 30 day post-infection (dpi), and results were compared with ES antigens and the VetLine Trichinella kit. Statistical analyses were performed using one- and two-way analysis of variance.

Results: Both recombinant proteins were successfully expressed at expected sizes (10.8 kDa for rTsp-LE; 6.8 kDa for rTnsp-4E) and induced strong, specific antibody responses. Antibodies against rTsp-LE and rTnsp-4E were detectable as early as 7 dpi, earlier than ES antigens (14-21 dpi). Immunized mice showed significant titers (up to 1:5700 for rTsp-LE and 1:10400 for rTnsp-4E by day 30). No cross-reactivity was observed with Echinococcus antigens. In rabbits, rTsp-LE showed the highest titers for T. spiralis infection, while rTnsp-4E was more specific for T. nativa. Overall sensitivity and specificity reached 100% and 88.2%, respectively.

Conclusion: Recombinant serine proteases rTsp-LE and rTnsp-4E demonstrated high sensitivity, species-specific reactivity, and early antibody detection, outperforming ES antigens. These findings support their potential as reliable candidates for serological assays, contributing to earlier and more accurate trichinellosis diagnosis and improved epidemiological surveillance.