Veterinary Quarterly最新文献

This review examines the role of the canine blood-brain barrier (BBB) in health and disease, focusing on the impact of the multidrug resistance (MDR) transporter P-glycoprotein (P-gp) encoded by the ABCB1/MDR1 gene. The BBB is critical in maintaining central nervous system homeostasis and brain protection against xenobiotics and environmental drugs that may be circulating in the blood stream. We revise key anatomical, histological and functional aspects of the canine BBB and examine the role of the ABCB1/MDR1 gene mutation in specific dog breeds that exhibit reduced P-gp activity and disrupted drug brain pharmacokinetics. The review also covers factors that may disrupt the canine BBB, including the actions of aging, canine cognitive dysfunction, epilepsy, inflammation, infection, traumatic brain injury, among others. We highlight the critical importance of this barrier in maintaining central nervous system homeostasis and protecting against xenobiotics and conclude that a number of neurological-related diseases may increase vulnerability of the BBB in the canine species and discuss its profound impacts on canine health.

Chronic Kidney Disease (CKD) is one of the most common conditions affecting felines, yet the metabolic alterations underlying its pathophysiology remain poorly understood, hindering progress in identifying biomarkers and therapeutic targets. This study aimed to provide a comprehensive view of metabolic changes in feline CKD across conserved biochemical pathways and evaluate their progression throughout the disease continuum. Using a multi-biomatrix high-throughput metabolomics approach, serum and urine samples from CKD-affected cats (n = 94) and healthy controls (n = 84) were analyzed with ultra-high-performance liquid chromatography-high-resolution mass spectrometry. Significant disruptions were detected in tryptophan (indole, kynurenine, serotonin), tyrosine, and carnitine metabolism, as well as in the urea cycle. Circulating gut-derived uremic toxins, including indoxyl-sulfate, p-cresyl-sulfate, and trimethylamine-N-oxide, were markedly increased, primarily due to impaired renal excretion. However, alternative mechanisms, such as enhanced bacterial formation from dietary precursors like tryptophan, tyrosine, carnitine, and betaine, could not be ruled out. Overall, the findings suggest that metabolic disturbances in feline CKD are largely driven by the accumulation of gut-derived uremic toxins derived from precursors highly abundant in the feline diet. These insights may link the strict carnivorous nature of felines to CKD pathophysiology and highlight potential avenues for studying preventive or therapeutic interventions.

Ex situ conservation is an important wildlife conservation strategy, but endangered wildlife in captivity often exhibit high disease rates. Commensal microorganisms are vital for homeostasis, immunity, and linked to diseases. This study analyzed the structure, assembly, variations of the symbiotic microbiota of the endangered crocodile lizard, and their relationship with environment, as well as the effects of captivity on them, to explore why captive reptiles face high dermatosis rates. Results showed that the reptile's microbiota significantly differ from that of its habitat, demonstrating niche specificity. While species richness among organs showed no significant differences, microbial diversity varied considerably. Skin microbiota showed no site-specific clustering. The assembly of skin, oral, and intestinal bacterial communities was dominated by homogeneous selection. The gut and oral bacterial networks were resilient to disturbances, while the skin bacterial network was sensitive. Captivity primarily affected the skin microbiota, reducing its diversity and stability, thereby increasing disease risk, and these effects were not solely attributable to environmental changes. These findings suggested that skin microbial changes in captive reptiles may be responsible for their increased susceptibility to dermatosis in ex situ conservation. This study underscored the importance of understanding reptile-associated microbes for effective conservation strategies and offers potential solutions.

Senecavirus A (SVA) is the causative agent associated with porcine idiopathic vesicular disease (PIVD), a condition indistinguishable from other foreign vesicular diseases affecting pigs. This complicates differential diagnosis and impacts the global swine industry. A diagnostic ELISA based on a non-structural viral protein has been developed, capable of distinguishing infected from vaccinated animals (DIVA). Different expression systems (eukaryotic and prokaryotic) were used to express recombinant proteins. The baculovirus-expressed SVA 3AB DIVA ELISA demonstrated a sensitivity of 96.67% and specificity of 96.67%. In contrast, the E. coli-expressed SVA 3AB DIVA ELISA achieved 100% sensitivity and 93.33% specificity. Both ELISAs strongly correlated with the reference method and showed no cross-reactivity with other pig pathogens. The E. coli system also provided a higher yield of expressed protein than the baculovirus system. These findings indicate that SVA DIVA ELISAs are effective alternatives for detecting SVA antibodies. They can be valuable tools for sero-surveillance and for evaluating immunity status tests to support and approve vaccination programs for pig herds in the future.

Salmonella Pullorum, the causative agent of pullorum disease, posing a significant threat to the global production of poultry meat and eggs. However, existing detection methods have substantial limitations in efficiency and accuracy. Herein, we developed a genomic deletion-targeted TaqMan qPCR assay for identification of Salmonella Pullorum, enabling precise differentiation from other Salmonella serovars. The assay's detection limit was 5 copies/μL of plasmid and 4 CFU/μL of bacterial DNA. Furthermore, we collected 676 chicken samples from an established infection model to compare the performance of the TaqMan qPCR assay with traditional bacterial culturing and antibody-based detection approaches. With superior sensitivity and specificity, the newly developed method detected over 80% of positive chickens, significantly outperforming the two conventional methods. Moreover, we proposed a combined framework that incorporates the advantages of TaqMan qPCR assay and antibody detection method, further enhancing the detection rate of positives to 92%. Additionally, to address the frequent aerosol contamination of amplification products in laboratory settings, we devised an easy-to-deploy anti-contamination system based on T7 exonuclease. Overall, the T7 exonuclease-assisted TaqMan qPCR assay will not only upgrade the current detection for pullorum disease, but also exemplify the feasibility of targeting specific genomic deletions for pathogen detection.

This study aimed to investigate the effects of dietary isatidis root polysaccharide (IRP) on diarrhea, immunity, and intestinal health in weanling piglets. Forty healthy piglets were randomly assigned to five groups receiving varying dosages of IRP. The findings indicated that different concentrations of IRP significantly reduced diarrhea scores (p < 0.01). Notably, the serum levels of immunoglobulin A and immunoglobulin G increased linearly and quadratically (p < 0.01), while immunoglobulin M also showed a linear increase (p < 0.05) in IRP-fed piglets. The secretory immunoglobulin A levels in ileal contents were significantly higher compared to control piglets (p < 0.01). Key intestinal health parameters, including villus height, villus height-to-crypt depth ratio, and goblet cell numbers, showed linear and quadratic increases in both the jejunum and ileum (p < 0.05), while crypt depth decreased significantly (p < 0.01). Additionally, the expression of IL-10, ZO-1, occludin, and mucin2 was upregulated linearly and quadratically in IRP-fed piglets (p < 0.05). In cultured IPEC-J2 cells, ZO-1 and occludin expression levels significantly increased upon exposure to 400 μg/mL IRP (p < 0.01). Furthermore, the relative abundances of Escherichia coli, Ralstonia pickettii, and Desulfovibrio fairfieldensis decreased linearly with increasing dietary IRP concentration. In conclusion, IRP shows promise as an effective dietary supplement for mitigating diarrhea and enhancing intestinal health in early weaned piglets.

Weaning stress-induced diarrhea is a serious issue in pig production. This study aimed to evaluate the potential of glucose oxidase (GOD) as an antibiotic substitute to alleviate diarrhea and improve gut health in weaned piglets. According to a randomized complete block design, 250 piglets weaned around 21 d of age were allocated into 5 groups (5 replicates/group), which received a basal diet without or with supplemental 200 mg/kg antibiotic, 500, 1000 and 2000 U/kg GOD, respectively. Dietary treatments did not affect (p > 0.05) growth performance of piglets. However, supplemental all doses of GOD were equivalent or superior to antibiotic to reduce (p < 0.05) diarrhea as well as increase (p < 0.05) thymus index, hepatic and colonic antioxidant properties. GOD addition at 1000 and 2000 U/kg reduced (p < 0.05) cecal and rectal pH value, respectively. They also displayed similar or superior efficacy to antibiotic in improving (p < 0.05) duodenal and jejunal morphology along with certain tight junction proteins expression of jejunum and colon. Collectively, GOD represents an antibiotic alternative to reduce diarrhea of weaned piglets through associating with ameliorations of intestinal structure and functions.

Infectious bronchitis virus (IBV) presents a major threat to global poultry production, necessitating a thorough understanding of its evolutionary relationships for effective control measures. This study presents a novel distance-based Minimum Span Clustering (MSClustering) method to cluster 311 IBV strains, with a comparison of its results to the established IBV classification. Phylogenetic network and recombination analyses were employed to investigate IBV evolutionary relationships and transmission pathways. The phylogenetic network revealed distinct clusters reflecting relationships between IBV strains. Importantly, these network patterns, combined with recombination event analysis, suggest an unrecognized role for migratory birds in IBV dissemination, highlighting potential transmission pathways beyond established poultry trade routes. These findings contribute to advancing our understanding of IBV evolution and support the development of targeted strategies for controlling viral outbreaks in poultry populations. While statistical limitations may affect threshold estimation for smaller networks, our MSClustering method significantly accelerates processing speeds-approximately 100,000 times faster than PhyML when analyzing the dataset-enabling comprehensive-scale phylogenetic analysis of viruses.

Canine mammary tumor (CMT) is a prevalent and destructive disease often diagnosed at an advanced stage, leading to poor outcomes. Currently, there is a lack of effective biomarkers for early detection and prognostic prediction of CMT. To improve CMT detection, we established a multiplexed immunoassay using a fluorescence bead-based suspension array system to measure serum levels of autoantibodies against four CMT-associated proteins (AGR2, HAPLN1, IGFBP5, and TYMS) in CMT patients. Our data revealed that serum levels of the four autoantibodies (anti-AGR2, anti-HAPLN1, anti-IGFBP5, and anti-TYMS) were significantly elevated in CMT patients (n = 158) compared to healthy individuals (n = 39). Notably, serum levels of anti-AGR2, anti-HAPLN1, and anti-TYMS in the dogs with stage I CMT (n = 56) were higher than those in the healthy group. Using a marker panel consisting of the four autoantibodies for detecting malignant CMT (n = 125) achieved a sensitivity of 50.4% and a specificity of 90%. Furthermore, higher levels of anti-AGR2, anti-HAPLN1, anti-IGFBP5, and anti-TYMS were associated with poorer survival in CMT patients. Collectively, we established a multiplexed immunoassay platform to detect serum autoantibodies and demonstrated that a tailored autoantibody marker panel shows potential clinical applicability for the diagnosis and prognosis of CMT.

Bovine mammosphere-derived epithelial cell (MDEC) cultures are heterogeneous and enriched for stem and progenitor cells. We previously reported that the bovine MDEC secretome, comprised of all bioactive factors secreted by the cells, displays regenerative properties, exerts antimicrobial effects, and modulates neutrophil activity, positioning it as a promising non-antibiotic biologic therapy for infectious diseases important to the dairy industry, like mastitis. Mastitis is defined as inflammation of the udder, and it is typically caused by bacterial infection. The effect of the MDEC secretome on macrophages, a first line of defense against bacterial infections in the udder, is unknown and could impact the utility of the secretome as a therapy for mastitis. To address this, we isolated bovine monocytes from peripheral blood and maintained them as an unpolarized (M0) population or polarized them into M1 or M2 phenotypes. Macrophages cultured with the secretome of bovine MDECs were assessed for their ability to phagocytose labeled bacterial particles and accumulate reactive oxygen species (ROS). We used single-cell RNA sequencing (scRNA-seq) and fluorescence-activated cell sorting (FACS) to isolate a subpopulation of MDECs that exert enhanced effects on macrophages. We found that the secretome of MDECs that do not express cluster of differentiation (CD) 73, a cell surface enzyme used as a marker for mesenchymal stromal cells, most strongly increased macrophage phagocytosis and ROS accumulation. These findings will help optimize the generation of the bovine MDEC secretome as a suitable treatment option for mastitis.