Frontiers in Veterinary Science最新文献

Background: Canine visceral leishmaniasis (CVL) is a vector-borne zoonotic disease caused by Leishmania infantum. This parasite has been reported in humans and dogs from Costa Rica over the past four decades as sporadic reports. In this study, we analyzed eight cases of autochthonous infections in dogs presumably originating from Santa Cruz, Guanacaste, and Santa Ana, San José, Costa Rica, none of which had a history of travel abroad.

Methods: Eight dogs with suspected CVL were analyzed using serological assays (Speed Leish K® (VIRBAC Diagnostics, France) or Antigen Rapid CaniV-4 (Leish)® (BIONOTE, Mexico)), five dogs were detected in 2023, and three during 2025. Histopathological staining was applied in cases with spleen, dermal, and lymph node involvement to determine the presence of Leishmania amastigotes. Blood, lymph node aspirates, conjunctival swabs, or cutaneous lesion swabs were also analyzed for the presence of Leishmania spp. ITS1, hsp70, and kDNA fragments. Phylogenetic and haplotype network analyses were conducted for hsp70 and kDNA data.

Results: Four dogs showed various clinical manifestations that included persistent anemia, thrombocytopenia, splenomegaly, exfoliative dermatitis, and onychogryphosis, whereas the other four dogs remained subclinical or asymptomatic. Histopathological analysis revealed numerous intracellular amastigotes in lymph node aspirates, spleen sections, and ear skin biopsy. Moreover, seven out of eight dogs were positive in the serological analysis, and the other seven to the Leishmania ITS1 PCR. Phylogenetic analysis of kDNA fragments revealed that sequences derived from our country clustered with those of L. infantum from the Old World, rather than with ones from Brazil, indicating a likely introduction from outside the Americas. All infected dogs received allopurinol and, when available, also meglumine antimoniate.

Conclusion: Infection with L. infantum in Costa Rican dogs was confirmed by clinical and laboratory evidence and thus represents the first autochthonous cases of CVL in our country. This study highlights the urgent need for routine canine testing, sandfly surveillance, access to proper treatments, and increased awareness, emphasizing the importance of public health policies for controlling leishmaniasis in both animals and humans from a One Health perspective.

Infectious bursal disease (IBD) is an important immunosuppressive disease of chicken caused by infectious bursal disease virus (IBDV). At present, the newly emerging novel variant IBDV (varIBDV) and the persistently prevalent very virulent IBDV (vvIBDV) are two major threats, while the non-var/vvIBDV, such as classic IBDV (cIBDV) and attenuated IBDV (attIBDV), also increases the complexity of clinical detection. In this study, a multiplex real-time quantitative fluorescence RT-PCR (qRT-PCR) was developed. Based on sequence analysis of different pathogenic IBDV strains, three probes with different fluorescent signals (FAM, VIC, CY5) and two pairs of primers were designed. Specifically, varIBDV exhibits three fluorescent signals (FAM, VIC, CY5), vvIBDV shows two signals (FAM, VIC), and non-var/vvIBDV displays one signal (FAM). The method possesses excellent specificity: no cross-reactivity was observed between different pathogenic IBDV types, nor with other common avian pathogens. This method has good reproducibility and high sensitivity, with a minimum detection limit of about 10 copies. Furthermore, in the detection of laboratory or clinical samples, the consistency rate of this method with the conventional sequencing analysis method reached 100%. In conclusion, this study developed for the first time a multiplex qRT-PCR that can universally detect IBDV and simultaneously distinguish between vvIBDV and varIBDV, which is of great significance for high-throughput emergency detection and comprehensive prevention and control of new IBDV epidemics.

Dichelobacter nodosus (D. nodosus) is the pathogen responsible for causing footrot in sheep and goats, which poses significant challenges to animal health and welfare. D. nodosus is classified into 10 different serogroups (A-I and M) based on the genetic variation of this fimbrial (fimA) gene. These fimbriae are immunogenic and play an important role in virulence, making serotyping of these fimbriae valuable for identification and vaccine development. In this study, three multiplex quantitative polymerase chain reaction (qPCR) assays, targeting the most commonly prevalent nine serogroups (ABC, DEF, and GHI), were studied for the detection of serogroups in foot swab samples collected from Dutch sheep farms. A total of 147 samples tested positive for D. nodosus using pnpA qPCR, and 144 (98%) samples exhibited a serogroup using qPCR. The multiplex qPCRs detected significantly more serogroups than conventional serogroup PCRs and detected more than one serogroup in a swab. In 46 samples (31%, 46/147), two to five different serogroups were identified from a single swab sample. In three samples, no serogroup was identified, likely due to sequence variation in the fimA gene in these samples. These direct multiplex qPCR tests provide faster, more sensitive, and accurate testing for the direct classification and quantification of D. nodosus serogroups for studying the epidemiology of footrot and for the formulation of serogroup-specific targeted vaccination strategies for prevention, control, and treatment of footrot.

Introduction: Antimicrobial resistance (AMR) is a global public health concern that requires a One Health approach. The role of veterinarians in promoting antimicrobial stewardship is essential for successful mitigation of AMR.

Objective: This study aimed to design a self-administered questionnaire and evaluate its reliability as a tool to assess veterinarians' knowledge, perceptions, and attitudes regarding AMR and antibiotic prescription and use in animals.

Methods: The questionnaire was developed based on a comprehensive review of relevant literature and by employing collective intelligence methodologies, including focus groups with veterinarians and pharmacists. For the pilot study, veterinarians working in the Northern region of Portugal were recruited. A test-retest was conducted with a 4-week interval. Reproducibility was determined with the intraclass correlation coefficient (ICC; 95% confidence interval) and internal consistency was calculated using Cronbach's alpha.

Results: In total, 31 (out of 34) veterinarians completed the retest phase of the study. Four sections with scale-items were assessed for reliability, with ICC values ranging from 0.10 (p = 0.285) in Section 2 (AMR) to 0.85 (p < 0.001) in Section 4 (prescription and antibiotic use). The questionnaire achieved Cronbach's alpha coefficient values of 0.81 and 0.78 in test and retest, respectively. Based on ICC values and veterinarians' comments, some items were deleted or reformulated.

Conclusion: The developed questionnaire is a reliable instrument capable of capturing veterinarians' knowledge, perceptions, and attitudes on AMR and antibiotic use.

A 6.08 kg female stray Arctic fox (Vulpes lagopus) of unknown age was presented with tail gland inflammation. Initial conventional therapy and subsequent tail amputation at a primary veterinary facility resulted in limited improvement. Subsequently, a topical medication red mercuric oxide (Hydrargyri Oxydum Rubrum) was applied for 4 weeks. Although the local infection showed signs of improvement, the fox subsequently developed progressive systemic signs, including anorexia, dark urine, and weight loss, prompting referral. Clinical examination revealed a large amount of cherry-red medication covering the wound. Hematological tests indicated elevated neutrophils and C-reactive protein (CRP), suggesting an inflammatory response. Serum biochemistry revealed elevated levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bile acids (TBA), indicating hepatobiliary injury, alongside an elevated creatine kinase (CK) suggestive of abnormal muscle metabolism. The whole-blood mercury concentration was significantly elevated (4.7583 μg/L). Imaging findings included: ultrasound showing gallbladder sludge, abnormal liver parenchyma echogenicity, and indistinct kidney contours; X-ray revealed gastric gas, liver edge extending beyond the costal arch, blurred renal contours, and significantly increased density in the tail gland area. The Arctic fox was diagnosed with chronic topical mercury (II) oxide-induced mercury poisoning and secondary liver injury. The treatment regimen included: (1) removal of the topical medication and surgical debridement; (2) intravenous administration of reduced glutathione (hepatoprotection), ceftiofur sodium (anti-infective), and vitamin C (antioxidant); (3) oral administration of a mercury chelating agent (dimercaptosuccinic acid) and choleretics (ursodeoxycholic acid); and (4) intramuscular injection of appetite stimulants. After 4 weeks of systemic treatment, the fox's abnormal biochemical parameters returned to normal, and the prognosis was good. This case addresses a specific gap in the diagnosis and treatment of heavy metal poisoning in wildlife. It provides a valuable reference for the clinical management of poisoning cases associated with topical mercury-containing wound medications.

One alternative to early cow-calf separation is continuous foster cow-calf contact, where one cow nurses two to four calves without being milked. However, multiple sucklings may compromise teat and body condition and affect fertility. Therefore, the prevalence of dry teats, teat lesions, abnormal body condition scores (BCS >3.75 or <2.5), rapid BCS changes (>0.5 absolute range), calving intervals, and number of inseminations to conception were compared between 18 foster cows kept in two groups of 11-12 cows with 46-48 calves and 18 milked cows in a commercial Holstein-Friesian herd. Four scorings were conducted in approximately 4-week intervals from weeks 2 to 16 postpartum. The final scoring was performed during weaning in one foster group and after weaning in the other. Associations between foster cows' BCS and teat lesions were further analyzed. Teat lesion prevalence was significantly higher in foster cows between weeks 10 and 14 postpartum, but not during or after weaning, indicating increasing calf independence from milk. Given that teat lesions may cause pain, increase infection risk, and reflect negative cow-calf interactions, they represent a welfare concern. No significant differences were found in teat dryness, overall body condition, or fertility outcomes. However, foster cows showed a trend toward overconditioning compared to milking cows (BCS > 3.75) from weeks 6 to 16, and foster cows with lesions had a numerically higher BCS compared to foster cows without teat lesions (medium effect size). These results suggest that large-scale studies are needed to investigate the causes of teat lesions, particularly in relation to individual cow acceptance of multiple suckling in foster systems.

Snakebite envenomation poses a significant threat to both public health and animal welfare, resulting in substantial human suffering and economic burden worldwide. Recognized by the World Health Organization as a neglected tropical disease, snakebites disproportionately affect impoverished rural regions across Africa, Asia, and South America, with an estimated 2.7 million envenomations and 81,000-138,000 deaths annually. In veterinary medicine, snakebites are similarly impactful, with up to 300,000 animals affected each year in the United States alone-primarily dogs and cats-while global veterinary cases likely number in the millions. Despite this, snakebites remain non-notifiable diseases, contributing to significant underreporting. The economic implications are profound, with treatment costs for human victims exceeding $200,000 per case and veterinary care ranging from $8,000 to $50,000 per case, often surpassing the financial capacity of pet owners. Beyond acute care, long-term sequelae such as chronic neuropathy and tissue damage further compound the burden. Current literature is limited in comparative analyses of envenomation mechanisms across species, particularly in livestock. This review will create a deeper understanding of pathophysiology, treatment modalities, and emerging therapies. Understanding of this background is essential to further advancements in science surrounding snake envenomation in both human and veterinary species.

Accurate identification of individual cattle is paramount in livestock insurance to combat fraud. However, the performance of existing muzzle recognition methods degrades in complex scenarios involving occlusion or multi-angle views. This study addresses this limitation by first constructing a comprehensive cattle muzzle image dataset encompassing frontal, multi-angle, and occluded conditions. We then propose CattleMuzzleNet, a lightweight recognition model that integrates a siamese network, an enhanced MobileViT backbone, and an Efficient Multi-scale Attention (EMA) mechanism for robust feature extraction and matching. Its efficacy is systematically validated through comparative experiments on feature extraction networks, ablation studies on the attention mechanism, and confidence threshold analysis. Evaluated on a dataset of 31,312 images from 658 cattle, CattleMuzzleNet achieved an accuracy of 97.87% and an F1-score of 98.89%, with a compact model size of 6.9 MB. The results demonstrate high accuracy and robustness in complex scenarios, providing an effective technical solution for identity verification in cattle insurance.

Although the carotid body (CB) has been widely examined in many animal species, its histological features in pigs have received comparatively little attention. This research presents the first integrative description of the porcine (CB), combining anatomical dissection, histological evaluation (H&E and Masson's trichrome), immunohistochemistry, and lectin histochemistry. In the study, four piglets were examined from which the carotid glomus was harvested, and it was described histologically. The organ displayed a multilobular structure embedded in connective tissue. Immunohistochemical labeling with GFAP, S100, and NSE demonstrated strong and consistent immunoreactivity, confirming the presence of neuroendocrine and glial-like cell populations. Complementary lectin histochemistry with Con-A and WGA revealed distinct glycosylation patterns that correlate with the presence of growth factor receptors (TrkA, TrkB, TrkC, p75NTR, and others), thereby offering insight into receptor biology and glycan-mediated signaling within the (CB).

Positive deviant (PD) farmers can be differentiated from the wider farming community by their inherent capacity to leverage farming innovations and technologies in addressing challenges faced in engaging in agricultural production. There is currently a limited body of literature on how positive deviance and entrepreneurial behavior allow some dairy farmers to develop strategies that enable them to cope better with and creatively overcome challenges faced by their peers. This study employed a positive deviance approach to identify innovative dairy farmers in urban and peri-urban areas of the Addis Ababa and Oromia administrative regions of Ethiopia. PD farmers were identified and selected through a descriptive study design, utilizing a purposive and snowball sampling approach based on the number of technologies adopted in a previous survey study and referrals from other farmers. Data were collected through key informant interviews and participant observation on selected farms. We observed that PD dairy farmers had adopted and/or modified a variety of technologies to overcome context-specific challenges faced, such as seasonal feed shortages exacerbated by climate change, reduced land size and availability of land for grazing and waste disposal, and restrictions on farming resulting from the development of urban areas. These technologies enabled farmers to improve feed production, manure disposal, breeding practices, the quality of livestock housing, and animal welfare and enabled them to control diseases and add value to milk production. This study underscores the important role that PD dairy farmers could play as social referents, not only for their peers in urban and peri-urban areas but also for policymakers, extension workers and academics who are interested in working with dairy farmers in co-identifying and co-developing solutions to challenges currently undermining the sustainability of the dairy sector in Ethiopia and beyond.