Journal of Veterinary Science最新文献

Importance: The brain and adipose tissue interact metabolically, and if there is a problem with the energy metabolism of the brain, it cannot maintain the energy balance with the adipose tissue. Therefore, when adenylate kinase 5 (AK5), which regulates energy metabolism in the brain, is knocked out, problems with lipid metabolism may occur.

Objective: We aimed to elucidate the metabolic function and phenotype of AK5, a gene with an unknown function in metabolism.

Methods: We generated AK5 knockout (KO) mice and administered high-fat and fasting diets to the mice to confirm their physiological phenotype and metabolic differences.

Results: In the high-fat diet (HFD) test, no differences in body weight, epididymal white adipose tissue (eWAT), or fat mass of AK5 KO mice were observed. In indirect calorimetry, the respiratory exchange ratio and activity counts increased in normal chow diet mice, but there was no difference between the HFD groups. At the mRNA level, there were no significant differences in the expression of lipid metabolism markers between wild-type and AK5 KO mice. Still, the glucose signal of adipocytes increased in AK5 KO mice. In the fasting test, the eWAT of AK5 KO mice was significantly reduced, as was the expression of lipid metabolism and inflammation-related immune markers. Thus, the apoptosis of adipocytes increased, and an imbalance in energy metabolism occurred.

Conclusions and relevance: When AK5 KO mice are energy deficient, it becomes difficult to use eWAT for energy storage, imbalance occurs, and apoptosis of adipocytes in eWAT increases.

Importance: Hemochromatosis is rare in domestic animals, and iron-induced myopathy has not been reported in veterinary medicine. This case is the first report of iron-overload myopathy owing to hemochromatosis in a dog.

Case presentation: A 9-year-old spayed female Donggyeong dog presented with severe forelimb lameness. Necropsy revealed an enlarged liver and hemorrhagic lesions in the forelimb muscle. Microscopy showed iron components accumulation in multiple organs, including the liver, forelimb skeletal muscle, spleen, lymph node, and kidney. Prussian blue staining identified iron deposits in both macrophages and parenchymal cells, indicating that the iron accumulation was acquired rather than hereditary. Furthermore, iron components were observed within muscle fibers, accompanied by severe atrophy and myositis.

Conclusions and relevance: Severe necrosis and mild fibrosis were observed in the liver and forelimb skeletal muscles. Based on histological analysis, we diagnosed iron overload myopathy by secondary hemochromatosis. Secondary hemochromatosis with severe muscle atrophy and myositis is very rare, and this is the first report of iron-overload myopathy in a dog.

Importance: African swine fever (ASF) is a contagious transboundary swine disease that poses a significant threat to the swine industry. As an archipelago, the Philippines has a geographic advantage in reducing ASF transmission risk. However, control efforts remain challenging due to the disease's complex epidemiology, lack of effective treatment, and vaccine availability. ASF transmission risk evaluation currently includes positive cases, population density, and pork production volume, but the potential role of contaminated pork commodities remains unexplored.

Objective: Using semiquantitative risk scoring, this study estimated the probability of ASF transmission in 23 selected provinces.

Methods: The factors influencing ASF spread were identified; 10 through a literature review and the positivity for ASF virus (ASFv) of meat samples from an ongoing surveillance study. Secondary data from each sampled province were collected, and the provinces were scored across these factors and classified into one of three risk categories.

Results: Six out of 23 provinces were categorized as high-risk due to the high number of ASFv-positive meat samples, backyard pigs, and ASF occurrences. Conversely, four provinces were classified as low-risk due to consistently low scores across all indicators. The difference in the meat contamination level between low- and high-risk provinces emphasizes the importance of including this factor in the ASF spread assessment.

Conclusions and relevance: Risk estimation of ASF transmission must consider meat sample contamination. Active surveillance at local borders can monitor contamination and prevent ASFv sources from entering areas. This approach allows the government to allocate resources and prioritize higher-risk areas.

Importance: This study is essential for comprehending the zoonotic transmission, antimicrobial resistance, and genetic diversity of enteropathogenic Escherichia coli (EPEC).

Objective: To improve our understanding of EPEC, this study focused on analyzing and comparing the genomic characteristics of EPEC isolates from humans and companion animals in Korea.

Methods: The whole genome of 26 EPEC isolates from patients with diarrhea and 20 EPEC isolates from companion animals in Korea were sequenced using the Illumina HiSeq X (Illumina, USA) and Oxford Nanopore MinION (Oxford Nanopore Technologies, UK) platforms.

Results: Most isolates were atypical EPEC, and did not harbor the bfpA gene. The most prevalent virulence genes were found to be ompT (humans: 61.5%; companion animals: 60.0%) followed by lpfA (humans: 46.2%; companion animals: 60.0%). Although pan-genome analyses showed no apparent correlation among the origin of the strains, virulence profiles, and antimicrobial resistance profiles, isolates included in clade A obtained from both humans and companion animals exhibited high similarity. Additionally, all the isolates included in clade A encoded the ompT gene and did not encode the hlyE gene. The two isolates from companion animals harbored an incomplete bundle-forming pilus region encoding bfpA and bfpB. Moreover, the type IV secretion system-associated genes tra and trb were found in the bfpA-encoding isolates from humans.

Conclusions and relevance: Whole-genome sequencing enabled a more accurate analysis of the phylogenetic structure of EPEC and provided better insights into the understanding of EPEC epidemiology and pathogenicity.

Importance: Enrofloxacin preparations are available for administration daily or every 3 days. This study presents clinical evidence to define which preparation is adequate to treat clinical cases of bovine respiratory disease (BRD) in calves.

Objective: To correlate the pharmacokinetics/pharmacodynamics (PK/PD) ratios of three pharmaceutical preparations of enrofloxacin with their clinical efficacy in treating BRD.

Methods: The PK/PD ratios of three enrofloxacin preparations were determined in healthy calves. Then, 48 BRD-affected calves initially treated IV with 2.2 mg/kg of flunixin-meglumine, were randomly assigned to treatment with: enrofloxacin dihydrate-hydrochloride (enro-C) 10% water suspension daily (10 mg/kg subcutaneous for three to six days); enro-C with alginate (enro-C/Al), and reference enrofloxacin (enro-R), both intended for treatment every 72-h in two occasions (10 mg/kg).

Results: The highest maximum plasma concentration (Cmax)/minimum inhibitory concentration (MIC) ratio was obtained with enro-C and the highest area under the curve (AUC)₀₋₇₂/MIC ratio with enro-R, and enro-C/Al exhibited an AUC₀₋₇₂/MIC smaller, but Cmax/MIC higher than enro-R. Based on repeated statistical measurements, clinical progress revealed that the best outcomes were observed with enro-C (p < 0.05), and no statistical differences resulted by comparing enro-C/Al with enro-R.

Conclusions and relevance: If the priority in calves affected by BRD is to speed up their recovery, and despite the more significant amount enro-C injected, using of lower doses of enrofloxacin as in the long-acting preparations is unsustainable. This study demonstrates that the clinical efficacy of enrofloxacin in cattle is optimally linked to Cmax/MIC rather than to AUC/MIC, which occurs better when injecting enro-C.

Importance: The composition of the gut microbiota is essential for a dog's health and its adaptation to the environment. Different bacteria can produce the same essential metabolites beneficial to health owing to bacterial functional redundancy in microbial communities.

Objective: This study examined the gut bacterial communities of dogs from different breeds, all kept under identical domestication conditions.

Methods: Noninvasive sampling and 16S rRNA high-throughput sequencing were used to compare the composition and function of the gut microbiota of three dog breeds: the Chinese Kunming dog (CKD), German Shepherd dog (GSD), and Belgian Malinois dog (BMD).

Results: The gut microbiota of the three dog breeds consisted of 257 species across 146 genera, 60 families, 35 orders, 15 classes, and 10 phyla. The dominant bacterial phyla across the three breeds were Firmicutes (57.44%), Fusobacteriota (28.86%), and Bacteroidota (7.63%), while the dominant bacterial genera across the three breeds were Peptostreptococcus (21.08%), Fusobacterium (18.50%), Lactobacillus (12.37%), and Cetobacter (10.29%). Further analysis revealed significant differences in the intestinal flora of the three breeds at the phylum and genus levels. The intestinal flora of BMD was significantly richer than that of CKD and GSD. The functional prediction and Kyoto Encyclopedia of Genes and Genomes analysis showed that the primary functions of the gut microbiota in these breeds were similar, with significant enrichment in various metabolic pathways, including carbohydrate and amino acid metabolism, secondary metabolite biosynthesis, and microbial metabolism in different environments. The intestinal flora of these breeds also played a crucial role in genetic information processing, including transcription, translation, replication, and material transport.

Conclusions and relevance: These results provide novel insights into the intestinal flora of intervention dogs and suggest novel methods to improve their health status, which help increase microbial diversity and normalize metabolite production in diseased dogs.

Importance: Rodents, particularly those inhabiting urban areas, are sources of infections that cause major human diseases. The number of recorded zoonotic infections has increased in recent decades, exacerbating public concerns. Zoonotic diseases in humans, such as capillariasis, hymenolepiasis, and toxoplasmosis, are life-threatening in severe cases, particularly in immunocompromised individuals. A thorough understanding of pathogens, particularly the parasites infecting rodents, is critical for predicting future zoonotic disease outbreaks and developing effective mitigation strategies. This review summarizes the information on parasites in rodents inhabiting Malaysia to identify the knowledge gaps that could serve as a foundation for future research.

Observations: Thirty-eight previous parasite studies in rodents conducted in Malaysia were reviewed, and 44 ectoparasites species and 58 endoparasites species across 19 rodent species were revealed. Six ectoparasite and eight endoparasite species were identified as zoonotic among these parasites. Morphological identification of parasite species typically succeeded only at the genus level because of their identical morphological characteristics. However, these studies used a molecular approach to identify parasites at the species level using species-specific primers. The pathological findings of various organs of infected rodents were also summarized, including gross and histological lesions exhibited by parasites.

Conclusions and relevance: This review highlights the list of parasites infecting rodents in Malaysia, provides information on the molecular and pathological findings from previous studies, and identifies some of the limitations and knowledge gaps that suggest future research to address the issues, including the paucity of information on blood parasites, molecular, and histopathological studies of parasites in rodents.

Importance: Gastrointestinal nematodiasis poses significant economic losses in the livestock industry due to mortality, morbidity, and decreased production.

Objective: This study examined the prevalence of gastrointestinal nematodiasis in dairy cattle in Central Inner Mongolia, Northern China, the associated risk factors, and the effects on the pepsinogen and gastrin levels.

Methods: Fecal samples (n = 590) were collected from four regions and analyzed using the standard floatation and sedimentation techniques. The serum gastrin and pepsinogen levels were also assessed as potential biomarkers for gastrointestinal nematodiasis.

Results: Among 590 animals, 259 (43.9%; 95% confidence interval, 36.7-49.8) tested positive for at least one type of gastrointestinal nematode parasite. Among the positive animals, 38.6% were poly-parasitic, while 61.4% were mono-parasitic (p < 0.05). Cooperia was the predominant nematode among mono-infections, accounting for 10.8%, followed in order by Oesophagostomum (10.0%), Trichuris (9.6%), Trichostrongylus (8.5%), Dictyocaulus (6.9%), Ascarid (6.9%), Haemonchus (4.6%), and Strongyloides (3.9%). Among the poly-parasitic infected cattle, 22.7%, 9.3%, 4.2%, and 2.3% had two, three, four, and five parasite combinations, respectively. The risk factors, such as age, breed, area, physical condition, and presence of diarrhea, were significantly (p < 0.05) associated with the prevalence of gastrointestinal nematodiasis. Poly-parasitic infected cattle showed 49.1% higher (p = 0.013) serum pepsinogen levels than the control group, while the mono-parasitic ones exhibited a 28.33% increase (p = 0.030). Similarly, the serum gastrin levels increased by 99.2% (p = 0.004) and 71.3% (p = 0.015) in the poly-parasitic and mono-parasitic animals, respectively.

Conclusions and relevance: These findings demonstrate the high prevalence of gastrointestinal nematodiasis in Northern China, with an alarming rate of poly-parasitic infections. In addition, polyparasitic infections affect the enzymes pepsinogen and gastrin levels.

Importance: In veterinary orthopedics, addressing foramen stenosis in the L7-S1 region in dogs presents significant challenges due to limited access and visualization with conventional surgical techniques.

Objective: This study aims to evaluate endoscopic foraminotomy through the iliac window, using three-dimensionally (3D) printing guide based on the preoperative plan, in cadaveric dogs.

Methods: Trans-iliac foraminotomies were performed on each side of five canine cadavers using and individualized 3D printing guide. The intervertebral foramen (IVF) area was divided into entrance, middle, and exit zones and the trajectory angle was calculated from the computed tomography data.

Results: Trans-iliac foraminotomy with an endoscope through the iliac hole using a 3D printed guide provide good visual access to the L7-S1 region. The variations in IVF in three zones were not significantly different after surgery. The angle of deviation of the guide was not significantly different caudally or ventrally after surgery. The mean trajectory angle after surgery was 14.06 ± 4.61°caudally and 13.07 ± 6.79° ventrally.

Conclusions and relevance: Our results suggest that surgical site were directly visualized during foraminotomy by the lateral approach through the spinal endoscope. However, other procedure including corpectomy and discectomy were not performed in this study.

One Health is a multisectoral cooperative and collaborative approach aimed at achieving integrated health by recognizing the interconnectedness of people, animals, plants, and the environment. In the modern world, the One Health approach is considered an essential perspective for overcoming various emerging diseases, including antimicrobial resistance (AMR). One of the top priority AMR infections is caused by carbapenem-resistant Enterobacterales (CRE), which are bacterial strains not susceptible to carbapenems, the last-resort antibiotics for clinical Gram-negative bacterial infections. Although carbapenems are not allowed to use in animals in the global community, various types of CRE are being reported among animals, including the carbapenemase-producing Enterobacterales (CPE). Therefore, since the dissemination and clinical infection of CPE represent a shared health threat, measures to raise awareness of this issue should be considered from the perspective of the One Health approach.