Journal of Veterinary Science最新文献

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 AUC_0-72/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: 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: Patients with arthritis and ruptured cruciate ligaments typically require surgery. Following surgery, it is necessary to improve joint function in early stage.

Objective: This study aimed to investigate the impact of intraoperative intra-articular injection of the ELHLD peptide (L-glutamyl-L-leucyl-L-histidyl-L-leucyl-L-aspartic acid) on postoperative stifle function in patients with medial patella luxation grade 3 and osteoarthritis grade 2 undergoing tibial plateau leveling osteotomy due to anterior cruciate ligament (ACL) rupture.

Methods: A total of 12 dogs participated, with 6 dogs assigned to the control group and 6 to the ELHLD peptide treatment group. The ELHLD peptide was administered by intra-articular injection to patients, and the following aspects were compared with the control: hindlimb circumference, balance evaluation score (BES), muscle mass, and stifle function score (SFS). These assessments were conducted at 2, 4, 8, and 12 weeks after surgery.

Results: In the treatment group, hindlimb circumference suggested an effect on the recovery stifle function at the 4th and 8th week (p < 0.05) after surgery, and the BES and muscle mass test were effective at 4th week (p < 0.05). In the SFS test, it was effective at 2nd week (p < 0.05).

Conclusions and relevance: The use of ELHLD injections is meaningful in that it helps rapid recovery of joint function in the early stages after surgery. This research might improve the satisfaction of the caregiver, and facilitate the overall recovery process in the patient.

Importance: Tracheal stenosis in cats, often resulting from endotracheal intubation, can cause life-threatening respiratory emergencies, requiring prompt and effective treatment. In this case, we demonstrate that tracheal stenting can effectively manage respiratory distress caused by tracheal stenosis in cats.

Case presentation: A 12-year-old neutered male Russian Blue cat presented with progressively worsening open-mouth breathing and coughing that began post-intubation and inhalation anesthesia for dental scaling 5 months before presentation. Computed tomography revealed a broad-based lesion protruding into the tracheal lumen at the thoracic inlet, resulting in localized luminal narrowing. Tracheoscopy and brush cytology led to a provisional diagnosis of tracheal stenosis with reactive hyperplasia and chronic granulomas caused by endotracheal intubation. Following diagnostic processes, the cat experienced severe respiratory distress, eventually leading to a stupor. Respiratory distress was alleviated after tracheal stent placement. The cat was prescribed anti-inflammatory drugs, antibiotics, bronchodilators, and antitussives and was discharged after 2 days of hospitalization. The stent remained well-positioned during the 27-month follow-up, with no complications or mucosal regrowth observed at the stenosis site.

Conclusions and relevance: This case is the first instance of using tracheal stenting to effectively manage tracheal stenosis in a cat, successfully resolving a respiratory emergency, and ensuring long-term care.

Importance: Chromatin accessibility is vital for gene regulation, determining the ability of DNA-binding proteins to access the genomic regions and drive transcriptional activity, reflecting environmental changes. Although human and murine studies have advanced the understanding of chromatin dynamics, domestic animals remain comparatively underexplored despite their importance in agriculture and veterinary medicine. Investigating the accessibility of chromatin in these species is crucial for improving traits such as productivity, disease resistance, and environmental adaptation. This review assessed chromatin accessibility research in domestic animals, highlighting its significance in understanding and improving livestock traits.

Observations: This review outlines chromatin accessibility research in domestic animals, focusing on critical developmental processes, tissue-specific regulation, and economically significant traits. Advances in techniques, such as Assay for Transposase-Accessible Chromatin using sequencing, have enabled detailed mapping of regulatory elements, shedding light on epigenetic regulation of traits, such as muscle development and productivity. Comparative studies have uncovered conserved and species-specific cis-regulatory elements across multiple species. These findings offer insights into regulatory mechanisms that can enhance breeding strategies and animal management. In addition, high-throughput techniques, such as single-cell analysis and deep-learning models, have advanced the study of chromatin accessibility in lesser-studied species.

Conclusions and relevance: Chromatin accessibility is crucial in gene regulation in domestic animals, influencing development, immune response, and productivity. Despite the progress, more comprehensive epigenomic datasets and cross-species analytical tools are needed to harness chromatin accessibility in domestic animal research. Understanding these mechanisms has practical applications in improving livestock traits, advancing breeding programs, and developing disease-resistant animals, highlighting the importance of integrating epigenetic and genomic tools for enhancing animal health and productivity.

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: Accurate age estimations in dogs are essential for various veterinary and clinical applications. Traditional methods based on dental appearance are error-prone because of external influences, necessitating the development of more precise methodologies.

Objective: This study examined the association between chronological age and pulp to tooth (P/T) volume ratio in dogs using computed tomography (CT) of the right maxillary canine and right maxillary fourth premolar (PM4) teeth.

Methods: Ninety-five canine skulls, aged five to 216 months, were examined using a two-slice CT scan machine. Volumetric analyses of the right maxillary canine and PM4 were performed. Statistical analysis, including Spearman's correlation and regression analysis, was conducted to assess the relationship between age and the P/T volume ratio.

Results: This study included 60 male and 35 female dogs, with no significant age difference between genders (p = 0.655). A strong negative correlation was observed between age and the P/T volume ratio for the right maxillary canine (r = 0.88, p < 0.001) and PM4 (r = 0.77, p < 0.001) teeth. Logarithmic regression models provided a better fit for age prediction (R² = 0.78 for the right maxillary canine, R² = 0.67 for PM4) compared to linear models.

Conclusions and relevance: CT-based volumetric analysis of the P/T ratio in the right maxillary canine and PM4 teeth offers a precise, non-invasive method for estimating the age of dogs. This technique can improve the accuracy of age estimations, particularly in forensic and clinical settings, providing valuable insights for veterinarians and researchers.

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.