Veterinary journal最新文献

Abomasal ulcers are frequently observed in slaughtered cattle and can adversely affect animal health and productivity. Motilin, ghrelin, and gastrin are gastrointestinal hormones involved in motility, mucosal integrity, and acid secretion, and may serve as potential biomarkers for gastrointestinal diseases. This study aimed to investigate the relationship between abomasal ulcers, ulcer severity, and serum levels of these hormones, and to evaluate their diagnostic value in fattening cattle. A total of 44 male Holstein cattle aged 16-18 months were clinically evaluated and subsequently slaughtered. Blood samples were collected before transport, and abomasal tissues were examined macroscopically and histopathologically post-mortem. Based on lesion characteristics, animals were classified into three groups: Control (n = 20), mild ulcer [AB(M), n = 15], and severe ulcer [AB(S), n = 9]. All detected ulcers were categorized as Type I following histopathological confirmation. No significant differences in serum motilin, gastrin, or ghrelin levels were observed between the Control and AB(M) groups (P > 0.05). Significantly higher levels (P < 0.001) of motilin, gastrin, and ghrelin were observed in the AB(S) group compared with both the Control and AB(M) groups. No significant differences (P > 0.05) were observed between the Control and AB(M) groups. Moreover, strong positive correlations were observed between all hormone concentrations (r = 0.94-1.00; P < 0.001). ROC analysis indicated that motilin (AUC = 0.781), ghrelin (AUC = 0.781), and gastrin (AUC = 0.829) showed potential for distinguishing cattle with moderate Type I abomasal ulcers from healthy animals, whereas in severe ulcer cases all three markers showed markedly higher diagnostic performance (motilin AUC = 0.878, ghrelin AUC = 0.878, gastrin AUC = 0.956), supporting their use as valuable diagnostic tools, particularly for the identification of severe disease. These findings suggest that serum motilin, gastrin, and ghrelin levels may be useful indicators of abomasal ulcer severity in cattle.

This study aimed to determine the pharmacokinetic behaviour of omeprazole (OMP) and its metabolites in sheep and goats following both intravenous (IV) and oral (PO) administration. Twelve one-year-old female animals, comprising six Awassi sheep and six Alpine goats, were used to compare pharmacokinetic parameters after a single dose of OMP (1.0mg/kg IV and 4.0mg/kg PO). Plasma levels of OMP, hydroxyomeprazole (OMP‑OH), omeprazole sulfone (OMP‑Sulfone), and omeprazole sulfide (OMP‑Sulfide) were measured at specified time points. Results revealed that the pharmacokinetic profiles of OMP in sheep differed significantly from those in goats for both IV and PO routes. After IV administration, sheep showed greater systemic exposure (AUC0‑∞: 1.84 ± 0.38µg·h/mL) and a longer elimination half-life (T1/2λz: 0.26 ± 0.05h) compared to goats (AUC0‑∞: 0.67 ± 0.16µg·h/mL; T1/2λz: 0.14 ± 0.03h). Conversely, following PO administration, OMP bioavailability was low in both species, with sheep displaying an AUC0‑∞ of 0.81 ± 0.38µg·h/mL (F %: 11.00) and goats 0.33 ± 0.21µg·h/mL (F %: 12.31). Metabolites OMP‑OH and OMP‑Sulfone were not detected in plasma after PO dosing in either species. However, after IV dosing, metabolite levels were higher in sheep than in goats. Consequently, these findings may support the development of more rational therapeutic strategies for the use of OMP in small ruminant medicine.

Vascular endothelial growth factor A (VEGF-A) plays a key role in tumour angiogenesis, proliferation, and metastasis, contributing to malignant transformation. Bevacizumab is a monoclonal antibody (mAb) which binds to VEGF-A, preventing it from binding to and activating VEGF receptor 2 (VEGFR-2) on endothelial and cancer cells, thereby resulting in anti-tumour effects. Bevacizumab is employed in treatment of numerous human malignancies and showed promising results also against head and neck squamous cell carcinoma (HNSCC). Feline oral SCC (FOSCC), the counterpart of HNSCC in cat, is characterized by aggressive behaviour, local invasion and metastasis, and is unresponsive to standard treatments, thus displaying poor prognosis. In this study, we characterized expression of VEGF-A/VEGFR-2 pathway in FOSCC cell lines SCCF1, SCCF2 and SCCF3, and tested the response to Bevacizumab both in vitro and in a xenograft mouse model of SCCF3 expressing luciferase. RT-PCR and Western blotting (WB) analysis showed expression and activation of VEGF-A/VEGFR-2 axis at steady-state and serum-starved conditions in the three cell lines, suggesting the presence of a functional autocrine signalling loop. Treatment of cells with Bevacizumab at 50 or 100 µg/mL for 6 h inhibited activation of VEGFR-2 and its downstream mediator AKT, as shown by WB and densitometric analysis. Most importantly, volumetric and bioluminescence analysis demonstrated that Bevacizumab (5 mg/kg, twice a week) suppressed tumour growth in the xenograft model. Our data suggest that Bevacizumab displays anti-cancer activity against FOSCC in vitro and in vivo, paving the way for translational studies aimed at introducing molecular targeted therapy with mAbs in veterinary oncology.

Highly virulent porcine reproductive and respiratory syndrome virus 1 (PRRSV-1) strains, such as the Rosalía strain, continue to emerge in the swine industry. The mechanisms by which these strains induce lung pathology are not clearly understood. This study aimed to characterise the lung histopathological lesions and immune responses induced by the highly virulent Rosalía strain in experimentally infected piglets. Infected animals developed severe lung lesions, including extensive interstitial pneumonia, multifocal proliferative and necrotising pneumonia (PNP), and to a lesser extent, bronchopneumonia. Marked expression of von Willebrand factor (vWF) and reactive morphological changes in endothelial cells was observed, suggesting endothelial activation and increased vascular permeability which contributed to local inflammation. Throughout the course of infection, dynamic shifts in immune cell populations were observed. At 10 days post-infection (dpi), lung infiltrate was dominated by T cells and calprotectin⁺ myeloid-like cells, with a moderate presence of CD20⁺ cells, alongside a marked depletion of CD163⁺ pulmonary alveolar macrophages. Interestingly, CD163⁺ septal macrophages infiltrated areas around PNP and bronchopneumonia lesions, with several cells displaying spindle-shaped morphology. By 35 dpi, there was a replenishment of CD163⁺ cells and a significant increase in CD20⁺ cells, indicating a shift from an early innate to an adaptive immune response. The presence of tertiary lymphoid structures (TLS) with abundant CD20⁺ cell aggregates at this stage further supports sustained local immune activation. Our findings highlight immunopathological mechanisms underlying the severity of disease caused by the highly virulent Rosalía PRRSV-1 strain, characterised by severe lung immune dysregulation, macrophage depletion, endothelial activation, and delayed B-cell lymphoid response.

Apramycin is an aminoglycoside antimicrobial that is used in livestock but interest has emerged in repurposing it for use in humans with multidrug resistant Gram negative bacterial infections. A scoping review was performed to identify available evidence pertaining to the efficacy of apramycin in animals, as part of assessment of its use in animals and potential issues that might emerge with re-purposing the drug for use in humans. Thirty eligible studies were identified, reporting data from 44 trials (1-3 trials/study, median 1). Studies were predominantly from before 1990. Most studies involved pigs, cattle and poultry, and assessed apramycin for prevention or treatment of enteric disease caused by E. coli. When studies of growth promotion (n = 6), parenteral administration (which is no longer used as an injectable version is not available, n = 9) and experimental infection (n = 1) are removed, only 28 trials from 18 studies reported evaluation of clinical outcomes with currently available formulations. Study design was often poorly described and statistical analyses were often superficially reported or not reported. Overall, a statistically significant beneficial effect of apramycin vs one or more comparisons was reported for 17/44 (39%) trials. No statistically significant effect was reported in two (4.5%) trials. The remaining inferred effects, either without a comparison group (uncontrolled studies) or without statistical analysis between groups. Data suggest that apramycin can be effective for the treatment and prevention of enteric disease in calves, piglets, poultry and rabbits, at least under certain production systems, predominantly against disease caused by E. coli, but more robust data and studies involving current production systems are needed.

Pigeon adenovirus (PiAdV) can cause symptoms such as dyspnea, indigestion, and growth retardation in pigeons. It endangers pigeon health and causes significant economic losses for breeders. However, the replication characteristics and pathogenicity of PiAdV still need to be studied. In this study, we investigated the replication capacity, pathogenicity, transmissibility, and morphogenesis in liver tissue of a type I PiAdV strain isolated from a pigeon in Shanxi, China. Results revealed that PiAdV infection led to weight loss and 100% mortality in infected pigeons. PiAdV is transmissible among pigeons via indirect contact. The liver is an important organ for virus replication and has significant pathological damage. Viral progressively assemble into mature virions within hepatocytes, forming honeycomb-like viral factories in the nuclei. The above findings indicate that type I PiAdV exhibits pathogenicity and transmissibility, highlighting the need to accelerate the development of vaccines and antiviral drugs to control its spread and prevalence.

Calves sold at weaning are the primary source of revenue for cow-calf producers. Therefore, implementing preventative health management practices to prevent infectious disease and mortality in calves is essential. However, which practices are most appropriate to recommend is unknown and depends on the particular herd and its constraints. The objectives of this study were to: 1. develop a calf health decision tool that consolidated evidence and guided discussion about recommended practices to prevent morbidity and mortality in preweaned beef calves, and 2. evaluate if the tool was useful in facilitating discussions between producers and veterinarians. The tool was developed based on the findings of: 2 systematic reviews, an expert consensus study, and several regional and national benchmarking studies. It was structured to identify areas of risk within an operation then to offer related evidence-informed control measures (e.g., recommended or beneficial practices). To evaluate its usefulness, two veterinarians piloted the tool with nine producers representing herds with different statuses of disease outbreaks. Most the producers and veterinarians stated that the tool helped support discussions and that its layout was easy to follow. The findings of this study narrowed a critical knowledge gap concerning recommended practices by compiling available evidence into a tool that was useful for facilitating discussions about herd risk and potential practices to implement on a given operation. Overall, its use may help prevent morbidity and mortality in calves and enhance the veterinarian's collaborative role in preventative medicine on cow-calf operations.

Paratuberculosis is a fatal, enteritis of animals caused by Mycobacterium avium subsp. paratuberculosis (MAP). Uptake of MAP by macrophages initiates adaptive immune responses, detected as antigen-specific interferon-gamma (IFN-γ) release or specific antibodies in peripheral blood. MAP can subvert macrophage killing and there is often a long sub-clinical phase. Diagnosis of paratuberculosis by faecal culture or serum ELISA is problematic, particularly during the subclinical phase. Regimens which rely on these tests, may fail as animals may transmit infection for prolonged periods before their detection. Infected animals may develop early Th1 responses to MAP. Measuring IFN-γ produced in response to mycobacterial antigens may give an early indication of animals infected with MAP. Adaptation of the commercially available Bovigam™ test kit utilizing MAP-specific proteins as stimulants of the cell-mediated immune (CMI) response discriminates naturally and experimentally infected animals from uninfected ones. Young animals from farms affected by paratuberculosis, exhibit high responses to purified protein derivative from Mycobacterium avium species (PPDa) and MAP-specific antigens. To determine if specific high CMI responses were diagnostic for paratuberculosis they were compared with the inferred true status of each animal in a latent class analysis. Results from this study indicate that the novel interferon gamma release assay (IGRA) test is a sensitive test of MAP infection but does not indicate which animals are likely to subsequently test positive by the established MAP tests. The IGRA test may have an application as a herd test, determining whether infection exists and to what extent it is present within the herd.

Objective: To evaluate the novel therapeutic Snoretox-1 for the treatment of Brachycephalic Obstructive Airway Syndrome (BOAS) in British bulldogs.

Methods: A therapeutic (Snoretox-1) was developed consisting of a muscle-toning protein (tetanus toxin) and an antibody trap (decoy), previously demonstrated via in vivo studies to functionally increase local muscle tone in the presence of neutralising antibodies. British bulldogs with grade 2 or 3 BOAS were treated, under sedation, by injection of the therapeutic bilaterally into the centre of the rostral geniohyoid. Bulldogs were graded by an accredited unblinded observer utilising the Respiratory Functional Grading (RFG) scale, after a three-minute trot test, at multi-week intervals, until any improvement returned to baseline values.

Results: Six British bulldogs were enrolled in this study (two male, four female) aged between 4 and 8 years old. All dogs improved by at least one BOAS grade on the RFG scale. Non-parametric statistical analysis (Friedman χ² with Durbin-Conover post-hoc tests) showed that BOAS severity grades recorded after Snoretox-1 treatment at time points up to 12 weeks were significantly lower than after placebo (p < 0.001), with improvements lasting from 20 to 53 weeks post-treatment. Feeding difficulty for up to 5 ½ weeks may occur with incorrect placement outside the rostral geniohyoid.

Conclusions: Injection of the Snoretox-1 muscle-toning therapeutic decreased the severity of BOAS in British bulldogs by one grade or more for a period of between 20 weeks and 53 weeks.

Clinical relevance: Snoretox-1 could offer a less invasive, well-tolerated and effective treatment for BOAS.