BMC Veterinary Research最新文献

The canine distemper virus (CDV) could infect various wildlife species worldwide. The viral infection in large felids directly impacts wildlife conservation. This study aimed to understand better the burden of CDV outbreaks in captive tiger populations in Thailand and a novel discovery of their clinical signs with a history of CDV exposure. We followed up on their infection from May 2016 to October 2020 with laboratory testing and veterinary medical records. The cumulative morbidity and mortality rates were relatively high. Moreover, 50% of the tigers survived at 2 years after infection. All suspected and confirmed cases of CDV infections were significantly associated with laryngeal inflammation, which developed into paralysis in almost 50% of cases. Altogether, 50% of all tiger cases with chronic infection developed stridor at 314 days after virus infection [95% CI: 302-320]. Therefore, laryngeal paralysis may result from CDV infection and degeneration, potentially affecting the peripheral and central nervous systems. This condition could pose a life-threatening risk to tigers. The virus could spread quickly by contact with bodily excretion among tigers and fomite contamination once it affects a specific population. Implementation of biosecurity measures and vaccination is essential to mitigate the risk of disease spread and infection rates in tiger populations.

Background: Cystic echinococcosis is a parasitic cyclo-zoonotic disease caused by the taeniid Echinococcus and causes significant economic losses in livestock production, yet its impact is often overlooked and under estimated.

Methods: This study investigated the risk factors and economic impact of cystic echinococcosis in livestock, in Uganda's pastoral and agro-pastoral communities. In the study, 14,937 livestock were examined at selected slaughterhouses in Moroto, Kumi, Luwero and Nakasongola districts from March 2019 to February 2020. The visceral organs were examined for hydatid cysts during slaughter and the prevalence correlated with the risk factors got from livestock traders and livestock owners through questionnaire survey. Production losses and economic losses due to organ condemnations were also estimated.

Results: This is the first study to provide insights into the financial impacts and risk factors towards Cystic Echinococcosis (CE) in livestock in Uganda. The key significant risk factors for the persistence of CE in goats were place of origin from Lira (P ≤ 0.000), Nakasongola (P ≤ 0.002), Luwero and Bukedea (P ≤ 0.002), and tethering (P ≤ 0.001); in cattle was communal grazing (P ≤ 0.0000); and in sheep was being kept in large flocks (P ≤ 0.004). The total annual economic losses due to CE on livestock inspected in abattoirs in the study districts was USD 21,352.7 (1 USD = 3,809.3 UGX) of which 11.7% was due to organ condemnation and 88.3% due to livestock production losses. More significant mean annual economic losses per livestock species examined occurred in Moroto district among Zebu cattle USD 8.4, goats USD 1.4 and sheep USD 1.4 than other districts.

Conclusion: Results show that CE is a disease of significant economic and public health importance in PAP areas in Uganda with urgent need to create awareness and institute community-based control measures involving multistakeholder particiapation.to break livestock-dog cycle.

Pinctada fucata martensii (P. f. martensii) is one of the main pearl oysters cultured in artificial seawater in China. However, it is highly susceptible to pathogen infection under intensive cultivation near the coast. MicroRNAs (miRNAs), as an innovative and potent regulator of immune function, play a pivotal role in the immune response of pearl oysters to external stimuli and are a potent marker for the response of P. f. martensii to infection. This study identified two novel miRNAs, novel-13 and novel-44, from the whole transcriptome of the P. f. martensii hemocyte before and after infection with Vibrio parahaemolyticus. The dual luciferase results showed that novel-13 negatively regulated LAAO and novel-44 negatively regulated ILK. The activity of antioxidant-related enzymes increased significantly in the synthetic miRNA (novel-13 and novel-44) inhibitors and decreased significantly in the synthetic miRNA mimics. In the challenge experiment, injection with miRNA inhibitor increased the relative survival percentage by 10% compared with the control group. In conclusion, the overexpression of novel-13 and novel-44 can decrease the activity of immune and antioxidant-related enzymes, possibly affecting immune regulation in P. f. martensii by negatively regulating the LAAO and ILK target genes.

Background: Strongyle nematodes pose a major challenge in veterinary parasitology, causing significant economic losses in livestock due to resistance to conventional treatments. Current anthelmintics, like Ivermectin, often encounter resistance issues. This study aims to address these gaps by synthesizing Carbon Quantum Dots (CQDs) and Copper-Doped CQDs (Cu@CQDs) using glucose extract, and evaluating their nematicidal properties against strongyles in vitro. We assessed the nematicidal effects of CQDs and Cu@CQDs through larval feeding inhibition of first-stage larvae (L1), egg hatch inhibition (EHI), and the mobility and mortality of infectious larvae (L3s). Additionally, we conducted ultrastructural examinations of eggs and larvae and evaluated oxidative/nitrosative stress indicators, including total antioxidant status (TAS), protein carbonylation (PCO), lipid peroxidation (MDA), and oxidative DNA damage in homogenized samples of L3s.

Results: The synthesized CQDs displayed semi-spherical morphology with diameters under 30 nm. Cu@CQDs at 12.5 µg/ml achieved over 90% EHI and larval motility inhibition. Fluorescence microscopy confirmed over 90% larval feeding inhibition at the same concentration. Both CQDs and Cu@CQDs induced oxidative stress, indicated by decreased TAS and increased MDA, PCO, and oxidative DNA damage. Scanning Electron Microscopy showed that CQDs and Cu@CQDs penetrated the larvae cuticle, altered the tegument, caused larval mortality, and resulted in egg deformities.

Conclusions: Given the potential for resistance to Ivermectin, seeking suitable alternatives is essential. Cu@CQDs exhibit effects similar to Ivermectin, indicating their potential as novel antiparasitic agents against strongyles. These findings emphasize the importance of exploring alternative treatments to address resistance and enhance nematode control efficacy.

Background: Small extracellular vesicles (sEVs) derived from mesenchymal stem cells (MSCs) are recognized for their therapeutic potential in immune modulation and tissue repair, especially in veterinary medicine. This study introduces an innovative sequential stimulation (IVES) technique, involving low-oxygen gas mixture preconditioning using in vitro fertilization gas (IVFG) and direct current electrical stimulation (ES20), to enhance the anti-inflammatory properties of sEVs from canine adipose-derived MSCs (cAD-MSCs). Initial steps involved isolation and comprehensive characterization of cAD-MSCs, including morphology, gene expression, and differentiation potentials, alongside validation of the electrical stimulation protocol. IVFG, ES20, and IVES were applied simultaneously with a control condition. Stimulated cAD-MSCs were evaluated for morphological changes, cell viability, and gene expressions. Conditioned media were collected and purified for sEV isolation on Day1, Day2, and Day3. To validate the efficacy of IVES for sEV production, various analyses were conducted, including microscopic examination, surface marker assessment, zeta-potential measurement, protein quantification, nanoparticle tracking analysis, and determination of anti-inflammatory activity.

Results: We found that IVES demonstrated non-cytotoxicity and induced crucial genotypic changes associated with sEV production in cAD-MSCs. Interestingly, IVFG influenced cellular adaptation, while ES20 induced hypoxia activation. By merging these stimulations, IVES enhanced sEV stability and quality profiles. The cAD-MSC-derived sEVs exhibited anti-inflammatory activity in lipopolysaccharide-induced RAW264.7 macrophages, emphasizing their improved effectiveness without cytotoxicity or immunogenicity. These effects were consistent across day 3 collection, indicating the establishment of an effective protocol for sEV production.

Conclusions: This research established an innovative sequential stimulation method with positive impact on sEV characteristics including stability, quality, and anti-inflammatory activity. This study not only contributes to the enhancement of sEV production but also sheds light on their functional aspects for therapeutic interventions.

Streptococcus suis (S. suis) is a major pathogen in swine and poses a potential zoonotic threat, which may cause serious diseases. Many toxin-antitoxin (TA) systems have been discovered in S. suis, but their functions have not yet been fully elucidated. In this study, an auto-regulating type II TA system, ParDE, was identified in S. suis serotype 2 strain ZY05719. We constructed a mutant strain, ΔparDE, to explore its functions in bacterial virulence, various stress responses, and biofilm formation capabilities. The toxicity exerted by the toxin ParE can be neutralized by the antitoxin ParD. The β-galactosidase activity analysis indicated that ParDE has an autoregulatory function. An electrophoretic mobility shift assay (EMSA) confirmed that the antitoxin ParD bound to the promoter of ParDE as dimers. In the mouse infection model, the deletion of ParDE in ZY05719 significantly attenuated virulence. ΔparDE also exhibited a reduced anti-oxidative stress ability, and ΔparDE was more susceptible to phagocytosis and killing by macrophages. Moreover, the biofilm formation ability of the ΔparDE strain was significantly enhanced compared to ZY05719. Taken together, these findings indicate that the type II TA system ParDE plays a significant role in the pathogenesis of S. suis, providing new insights into its pathogenic mechanisms.

Background: Ovine pulmonary adenocarcinoma (OPA) is caused by Jaagsiekte sheep retrovirus (JSRV) and is considered an important potential animal model for human lung cancer. The precise mechanisms of OPA oncogenesis are still uncertain. The transcription factor signal transducer and activator of transcription 3 (STAT3) is activated by interleukin-6 (IL-6) in many cancers, but this aspect is unknown in OPA. We therefore aimed to evaluate the expression of IL-6 and STAT3 in OPA for its potential role in pulmonary carcinogenesis.

Results: Lung tissues from 9 grossly normal and JRSV-negative sheep and 20 cases of JSRV-positive OPA sheep were included in the study. Tissue samples were stained with antibodies against IL-6, STAT3, and JSRV-MA. IL-6 and STAT3 were further quantified in both groups using Western Blot (WB). Immunohistochemically, IL‑6 was expressed in stromal, inflammatory, and epithelial cells in all cases of OPA, while STAT3 immunoexpression was restricted to epithelial cells. In the OPA group, the percentage of immunolabelled cells for STAT3 accounted for a mean value of 96%. Using the H-SCORE method, 95% of cases were considered positive for STAT3 expression. Control tissues showed multifocal and weak immunoexpression for both markers. Using WB analyses, a highly significant amount of both IL-6 (p = 0.0078) and STAT3 (p < 0.0001) proteins were present in lung neoplasms, by comparison to the control lungs.

Conclusions: Our data showed overexpression of IL-6 and STAT3 in lung tissues from OPA compared to lungs from JSRV-negative sheep. These results suggest a potential role of IL6-STAT3 in OPA carcinogenesis.

Background: Lower urinary tract disease is a common clinical condition in dogs, usually presenting with dysuria, pollakiuria and haematuria. Diabetes mellitus is a predisposing factor for urinary tract infection in both humans and dogs and does not necessarily present with clinical signs. In this case report, we describe for the first time a case of cystitis glandularis in a dog with diabetes mellitus, associated with Escherichia coli urinary tract infection.

Case presentation: A 12 year old 9.2-kg (20.2-lb) castrated male Miniature Schnauzer with diabetes mellitus, was referred because of continued dysuria, pollakiuria and hematuria without a satisfactory response to treatment. The abdominal ultrasound revealed an irregular increase in mural thickness of the bladder, together with multiple immobile structures, apparently originating on the dorsal surface, of varied longitudinal diameters, with a convex hyperechogenic interface with an acoustic shadow. It was decided to perform a surgical cystotomy, which revealed that the surface of the urothelium showed dark hemorrhagic staining and multiple nodular structures, which were relatively hard to palpate. Histological examination of the bladder wall revealed hyperplastic urothelial epithelium, submucosal glandular formations with well differentiated mature cells and a chorion with signs of edema, concluding a diagnosis of cystitis glandularis. Bacteriological culture of the urothelium and urine revealed Escherichia coli infection. After initiation of antibiotic therapy and pain management, the dog's clinical signs improved markedly until complete remission of the bladder lesions.

Conclusion: Although there have been few reports of this clinical presentation in veterinary medicine, two in cats and one in a female schnauzer, this is the first reported case of cystitis glandularis associated with urinary tract infection due to Escherichia coli. The importance of bacteriological and histopathological studies in the diagnosis of urinary tract pathologies should be emphasized.

Background: The recently identified swine inflammation and necrosis syndrome (SINS) affects tail, ears, teats, coronary bands, claws and heels of affected individuals. The primarily endogenous syndrome is based on vasculitis, thrombosis, and intimal proliferation, involving defence cells, interleukins, chemokines, and acute phase proteins and accompanied by alterations in clinical chemistry, metabolome, and liver transcriptome. The complexity of metabolic alterations and the influence of the boar led to hypothesize a polygenic architecture of SINS. This should be investigated by a transcriptome study. For this purpose, the three to five least affected (SINS-low) and most SINS affected (SINS-high) 3d-old piglets, each of three boars, a relatively SINS stable Duroc boar (DU), a relatively stable Pietrain boar (PI+) and a highly susceptible Pietrain boar (PI-) were selected from 27 litters of mixed semen to minimize environmental effects.

Results: A genome-wide expression experiment revealed a huge set of differentially expressed genes that are involved in vasculitis, inflammation and necrosis, keratinization and erythrocyte epitopes. Among them were CRP, GYPA, S100A12, and LIPK. The results confirm and complement previous studies to this topic.

Conclusions: The results confirm the outstanding importance of defence in the context of SINS. At the same time, for the first time, there is evidence for a direct involvement of the keratinisation capacity of the skin and various epitopes of the erythrocyte membrane, which seem to be associated with the severity of SINS. These genes could serve to clarify the pathogenesis of the syndrome and to develop diagnostic tools in future studies.

With freshwater resources becoming scarce worldwide, mariculture is a promising avenue to sustain aquaculture development, especially by incorporating brackish and saline groundwater (GW) use into fish farming. A 75-day rearing trial was conducted to evaluate fish growth, immune response, overall health, and water quality of Chelon ramada cultured in brackish GW and fed on a basal diet (BD) augmented with rosemary oil (RO) or RO + zymogen forte™ (ZF) as an anti-flatulent. Five treatments were administrated in triplicate: T1: fish-fed BD without additives (control group); T2: fish-fed BD + 0.5 g RO /kg diet; T3: fish-fed BD + 0.5 g RO and 1 g ZF /kg diet; T4: fish-fed BD + 1 g RO /kg diet; T5: fish-fed BD + 1 g RO and 1 g ZF /kg diet. Three hundred fish (8.51 ± 0.01 g/fish) were housed in 15 fiberglass tanks (1500-L tank). The results revealed significant improvements (P < 0.05) in growth performance, survival, growth hormone, and insulin-like growth factor-1. Additionally, there were decreases in the feed conversion ratio (FCR) and the levels of nitrogen by-products (NH₄, NH₃, and NO₂) and pathogenic bacterial counts in the rearing water when fish were fed diets supplemented with RO and RO + ZF. Furthermore, significant reductions in the levels of plasma stress indicators (cortisol, creatinine, and glucose) were detected. In addition, there were significant enhancements observed in the levels of innate immune markers, such as white blood cells, total protein, albumin, and immunoglobulin. The complement system, specifically complement 3 and complement 4, also showed considerable improvements. Furthermore, there were increases in plasma heat shock proteins HSP70 and HSP90, as well as enhanced antioxidant activity. These gains were associated with healthier liver and intestines. The investigation demonstrated that adding 0.5-1 g RO / kg diet or RO + ZF to a C. ramada diet has many benefits, including reducing the levels of nitrogen by-product chemicals and pathogenic bacterial load in GW used in growth tanks. Furthermore, significant improvements were observed in the rates of growth and associated hormones, efficiency of feed utilization, blood indicators, immune function, condition of internal organs (namely the intestine and liver), and overall health of the fish.