Veterinary Sciences最新文献

Canine coronavirus (CCoV) is an important gastrointestinal pathogen that causes serious harm to pet dogs worldwide. Here, 1791 clinical samples were collected from pet dogs in different pet hospitals in Guangxi Province, southern China, for the 2021-2024 period and detected for CCoV by a multiplex RT-qPCR. The results showed that 8.43% (151/1791) of samples were positive for CCoV. Sixty-five positive samples were selected to amplify, sequence, and analyze S, M, and N genes. A sequence comparison revealed that the nucleotide and amino acid similarities of the S, M, and N genes were 94.86% and 94.62%, 96.85% and 97.80%, and 96.85% and 97.80%, respectively. Phylogenetic analysis indicated that 65 CCoV strains obtained in this study belonged to the CCoV-II genotype, of which 56 CCoV strains belonged to the CCoV-IIa subtype and 9 CCoV strains belonged to the CCoV-IIb subtype. A potential recombination event analysis of S gene sequences indicated that two CCoV strains, i.e., GXBSHM0328-34 and GXYLAC0318-35, have recombination signals. A Bayesian analysis indicated that the evolutionary rates of the S, M, and N genes were 1.791 × 10^-3, 6.529 × 10^-4, and 4.775 × 10^-4 substitutions/site/year, respectively. The population size grew slowly before 1980 and then began to shrink slowly; it then shrank rapidly in 2005 and expanded sharply in 2020, leveling off thereafter. These results indicated the CCoV strains prevalent in Guangxi Province, southern China, showed a high level of genetic diversity and maintained continuous variation among clinical epidemic strains.

Feline coronavirus (FCoV), as one of the important pathogens of feline viral gastroenteritis, has been attracting great attention. A total of 1869 rectal and nasal swabs, feces, and ascites samples were collected from eight regions in Guangxi province during 2021-2024. The multiplex RT-qPCR established in our laboratory was used to test these samples for FCoV, and 17.66% (330/1869) of the samples were positive for FCoV. The S, M, and N genes of 63 FCoV-positive samples were amplified and sequenced, and the genetic and evolutionary characteristics were analyzed. Similarity analysis showed that the nucleotide and amino acid homologies of S, M, and N genes were 81.2-99.6% and 70.2-99.5%, 89.9-100% and 91.6-100%, and 90.1-100% and 91.5-100%, respectively. Phylogenetic analysis revealed that all 63 FCoV strains, based on S gene sequences, belonged to type I FCoV (FCoV-I), and were clustered with Chinese strains and the Netherlands UU strains. Recombinant signals were detected in the S gene of strains GXLZ03-2022, GXLZ08-2022, and CCoV GD/2020/X9. The results suggest that FCoV is still prevalent in the Guangxi province of southern China, and the prevalent FCoV strains show high genetic diversity and novel epidemic characteristics.

(1) Background: Ultrasound attenuation imaging (ATI) is an innovative technique that allows for the evaluation of the degree of lipid infiltration of the liver parenchyma in a simple and non-invasive way. The objective of this study was to verify the applicability of the ATI method in the evaluation of hyperlipidemia. (2) Methods: This study included 53 dogs between January 2021 and December 2022, of which 21 were healthy (A) and 32 had hyperlipidemia (B). The dogs of Group B were divided into mild hyperlipidemic (B1; n = 15) and moderate/severe hyperlipidemic (B2; n = 17). Each dog underwent biochemical examination, B-mode ultrasound and ATI investigation at the liver level via a right intercostal approach. (3) Results: The mean AC value was significantly higher in Group B (0.95 ± 0.23 dB/cm/MHz) compared to Group A (0.81 ± 0.10 dB/cm/MHz). No statistically significant differences were highlighted regarding the ATI values between the subjects with mild and moderate/severe hyperlipidemia. (4) Conclusion: ATI could be a promising method for the non-invasive evaluation of hepatic steatosis in veterinary medicine.

Disease prevention is a cornerstone of herd management for minimizing preweaning calf mortality. However, scientific evidence about the usefulness of practices in herds is scarce. The first objective was for a group of veterinarians to determine which practices are most useful considering their effectiveness, ease of implementation, and economic feasibility. A second objective was for them to define which practices should be included in a tool to facilitate discussions between producers and veterinarians. Expert opinions and consensus were determined using a modified Delphi approach. During two questionnaire rounds, participants scored the effectiveness, ease of implementation, and economic feasibility of each practice. Overall scores for each practice were calculated, and feedback reports were sent to participants between rounds showing the groups' median responses. Consensus on which practices should be included in the tool was targeted during the workshops. Twelve veterinary experts participated. Administering clostridial vaccines and providing calves with colostrum in case they had not nursed were considered practices that were 'always useful for all herds'. However, most practices had intermediate levels of usefulness, and among these, antibiotics were considered the least useful. Nevertheless, all practices discussed during the workshops attained a consensus about being included in the future tool to facilitate on-farm discussions.

This research examines how sheep farmers and industry actors in the United Kingdom (UK) understand and conceptualize what animal welfare scientists term 'positive animal welfare'. It explores their awareness of the concept, and how they interpret it using a qualitative approach. Participants were recruited using a snowballing, purposive sample approach, resulting in 25 sheep farmers and 11 industry actors (veterinarians, farming organizations, advisors, and supply chain) being interviewed. To collect data, a combined approach involving semi-structured interviews and a facilitated workshop were used between April 2021 and March 2022. Data were then thematically analyzed using a hybrid of inductive and deductive coding process. The findings suggested that the perceptions of farmers and industry actors in the study regarding positive welfare differ from contemporary academic discourses. Overall, around 7 of the farmers equated positive welfare with "positive stockmanship", while six of them expressed "good animal welfare" definitions associated with the Five Freedoms. In contrast, most industry actors (6) expressed interpretations associated with high welfare standards (going above minimum recommended practices) and positive mental experiences (3). Emerging discourses revealed the link between self-identity, social identity and what positive welfare is, the importance of knowledge exchange, and the need for practical indicators through language rephrasing. There is a clear need to enhance and improve knowledge dissemination strategies, particularly in the UK, where much research is being conducted on positive animal welfare.

Roxarsone (ROX) is widely used as a feed addictive for livestock and poultry. ROX promotes angiogenesis, which can lead to health problems, and it is necessary to identify methods to counter this angiogenic effect of ROX. The VEGF/VEGFR2 signaling pathway is involved in the growth and reconstruction of new blood vessels during angiogenesis. In this study, a recombinant lentiviral vector encoding Vegfr2 shRNA was transfected into rat vascular endothelial cells and used in mouse matrigel plug and melanoma xenograft models to investigate its potential to regulate ROX-induced angiogenesis and tumor growth. Treating endothelial cells with ROX increased cell proliferation, migration, and a tube-like structure of growth relative to the control group. The addition of the lentiviral Vegfr2-silencing vector significantly attenuated the effects of ROX on endothelial cells. The hemoglobin content of mouse matrigel plugs treated with ROX was increased significantly. This effect was dramatically attenuated by the co-administration of shRNA targeting Vegfr2. The volume, weight and CD34 staining of the melanoma xenograft tumors increased by ROX were also attenuated by Vegfr2 silence. These results indicate that the down-regulation of VEGFR2 protein plays an inhibitory role in the ROX-promoted angiogenesis in vivo and in vitro. These data support the targeting of Vegfr2 gene as an effective means to treat ROX-induced angiogenesis and tumor growth.

Miranda donkeys are an endangered autochthonous breed of Portugal. The HemoCue WBC DIFF and HemoCue Hb 201 portable analyzers, developed as a simplified alternative method for total and differential WBC count and hemoglobin measurement, respectively, may be relevant tools in veterinary practice. This study aimed to validate these instruments using Miranda donkey blood samples. For the HemoCue WBC DIFF, most parameters showed acceptable intra- and inter-assay precision with coefficients of variation (CV) below 5%, except for monocytes and eosinophils with higher CVs. The HemoCue Hb 201 showed CVs of 1.98% and 4.07%. Linearity correlation coefficients (r) ranged from 0.53 to 0.99 for HemoCue WBC DIFF and 0.99 for HemoCue Hb 201. Significant levels for neutrophils, lymphocytes, monocytes, eosinophils, and Hb measurements varied. Comparisons with ProCyte Dx showed an excellent correlation for WBC (r_s = 0.96), neutrophils (r_s = 0.91), lymphocytes (r_s = 0.94), and eosinophils (r_s = 0.90) but a poor correlation for monocytes and basophils. The HemoCue Hb 201 showed a correlation of r_s = 0.96 with ProCyte Dx. In conclusion, both analyzers provided reliable results and are suitable for use in Miranda's donkey breed for WBC counts and Hb measurements.

In dogs, the risk of an acute hemolytic transfusion reaction at the first transfusion is negligible; however, mismatched transfusions may produce alloimmunization. To avoid fatal acute hemolytic reactions in subsequent blood transfusions, it is important to recognize blood groups and to blood type both the donor and the recipient. Prevalence of dog blood groups varies geographically and between breeds. Our aim was to determine DEA 1 prevalence in a canine population in Luanda (Angola) and to assess alloimmunization risk after a mismatched blood transfusion. Blood samples were typed using an immunochromatographic strip technique. Of the 112 dogs tested (59 males; 53 females), 52.68% were DEA 1 positive and 47.32% DEA 1 negative. Females tended to be DEA 1 positive, and males DEA 1 negative (p = 0.0085). In a first-time mismatched blood transfusion, the calculated probability of a dog becoming sensitized was 24.9% and the probability of an acute hemolytic reaction following a second incompatible blood transfusion was 6.21%. DEA 1 prevalence obtained was similar to that reported worldwide, but differs from other African countries. The risk of alloimmunization and acute hemolytic transfusion reactions in mismatched blood transfusions is higher than that in other African regions. Blood typing is recommended prior to transfusion.

Giardia duodenalis, Cryptosporidium parvum, Blastocystis spp. and Enterocytozoon bieneusi are four common zoonotic parasites associated with severe diarrhea and enteric diseases. In this study, we developed a multiplex PCR assay for the simultaneous detection of these four zoonotic protozoans in goat stool samples and assessed its detection efficiency. Specific primers were designed from conserved gene sequences retrieved from GenBank, and the PCR conditions were optimized. Genomic DNA from 130 samples was subjected to both single-target PCR and multiplex PCR. The multiplex PCR assay successfully amplified specific gene fragments (G. duodenalis, 1400 bp; C. parvum, 755 bp; Blastocystis spp., 573 bp; E. bieneusi, 314 bp). The assay sensitivity was ≥10² copies of pathogenic DNA clones with high specificity confirmed by negative results for other intestinal parasites. The detection rates were 23.08% (30/130) for G. duodenalis, 24.62% (32/130) for C. parvum, 41.54% (54/130) for Blastocystis spp., and 12.31% (16/130) for E. bieneusi, matching the single-target PCR results. The sensitivity and predictive values were 100.00%. This multiplex PCR provided a rapid, sensitive, specific, and cost-effective approach for detecting these four parasites. It also provided essential technical support for the rapid detection and epidemiological investigation of G. duodenalis, C. parvum, Blastocystis spp., and E. bieneusi infections in goat fecal samples.

The sugC gene of Streptococcus suis (S. suis) is a coding gene for the ATP-binding transporter-associated protein with strong pathogenicity. In order to reveal the effect of the sugC gene on the virulence of S. suis serotype 2, a wild-type strain of TJS75, isolated from fattening pigs' brain tissue samples, was used as a parent strain, and a knockout sugC gene (ΔsugC) and complementary strain (CΔsugC) were successfully constructed via homologous recombination technology. The biological characteristics of TJS75, ΔsugC and CΔsugC were compared and analyzed through growth curves, biochemical characteristics, hemolysis characteristics, cell infection tests and pathogenicity tests on BALB/c mice. The results of the growth characteristic experiments in vitro showed that the plateau stage growth period of ΔsugC was delayed compared to the TJS75 strain, but there was no difference in the total number of bacteria. The biochemical characteristics and hemolysis ability of ΔsugC in sheep blood had no difference compared with TJS75, but its adhesion and invasion abilities in PK-15 cells were decreased. Knockout of the sugC gene had no impact on the expression levels of adhesion-related genes in TJS75 in real-time PCR analysis. In addition, the LD₅₀ of ΔsugC in BALB/c mice was 1.47 × 10⁸ CFU, seven times higher than that of TJS75 (LD₅₀ = 2.15 × 10⁷ CFU). These results illustrate that the deletion of sugC reduced the virulence of TJS75 to BALB/c mice, but its role in the adhesion and invasion of PK-15 cells in this strain needs to be further explored. In summary, this study provides evidence that the sugC gene is a virulence-related gene in the S. suis serotype 2 strain and plays a crucial role in the adhesion and invasion of S. suis. This study lays a foundation for the further exploration of the potential virulence factors and pathogenesis of S. suis.