Acta Veterinaria Scandinavica最新文献

Background: Antibiotic treatments of diarrhoea in suckling piglets and in pigs after weaning are common worldwide and contribute to antimicrobial resistance (AMR) in Escherichia coli from pigs. In Sweden, during the last decades, resistance to trimethoprim-sulphonamide and ampicillin has increased markedly in E. coli from routine clinical samples from piglets with diarrhoea, hereafter referred to as "clinical submissions". This has occurred despite a comparatively low use of antibiotics in Swedish pig production. However, clinical submissions might be biased towards farms with treatment failures and therefore overestimate occurrence of AMR. To explore the representativeness of data from such samples we compared occurrence of AMR in E. coli from clinical submissions and from concurrent samples collected from piglets with diarrhoea by convenience, referred to as "study samples". We also investigated associations between farm-related potential risk factors and AMR using farm data collected through a questionnaire. Data were evaluated using univariable and multivariable statistical models, as well as a multivariate model.

Results: In all, 158 study samples from 97 herds and questionnaires from 83 herds were analysed. Resistance to streptomycin (37%), trimethoprim-sulphonamide (32%), ampicillin (30%), and tetracycline (18%) were the most frequent traits. Occurrence of AMR in 158 E. coli isolates from study samples was not significantly different from occurrence in 57 isolates from concurrent clinical submissions (P > 0.05). In 70% of herds, more than 10% of the sows were treated with antibiotics in the first week after farrowing, and trimethoprim-sulphonamide was the most common first choice antibiotic. Trimethoprim-sulphonamide resistance was associated with the proportion of sows receiving post-farrowing treatment. Resistance to ampicillin, tetracycline, and streptomycin resistances were indirectly associated with sow treatments, likely via co-resistance to trimethoprim-sulphonamide. There was no significant association between high dose zinc oxide supplementation and AMR (P > 0.05).

Conclusions: Clinical submissions do not overestimate occurrence of AMR in E. coli from Swedish piglets with diarrhoea and are therefore relevant for AMR monitoring. Even at low treatment rates, post-farrowing treatment of sows increases the risk for AMR in piglets. This applies especially for trimethoprim-sulphonamide resistance, but also for resistance to other antibiotics, and indicates that antibiotic use must be reduced substantially to achieve a reduction of AMR.

Calves are born agammaglobulinemic and depend on transfer of passive immunity from colostrum. Failure of transfer of passive immunity (FTPI) and adequate transfer of passive immunity (ATPI) are defined as serum immunoglobulin G (IgG) levels < 10 and ≥ 10 mg/mL, respectively. The objective of this study was to evaluate the level of passively transferred immunity in Danish dairy calves measured with Enzyme-linked immunosorbent assay (ELISA) and Brix refractometer. Blood samples from 834 calves (430 bull calves and 404 heifer calves) aged two to nine days were included in the study. Serum IgG concentration was determined by ELISA and percentage Brix (%Brix) with a digital refractometer. Median serum IgG concentration was 17.05 mg/mL and mean %Brix was 8.5%. A total of 592 (71.0%) and 242 samples (29.0%) had a serum IgG concentration ≥ 10 mg/mL and < 10 mg/mL, respectively. For %Brix 541 (64.9%) and 293 (35.1%) was ≥ 8.1 and < 8.1%, respectively. Serum IgG concentrations and %Brix measurements were highly correlated (r = 0.88). The level of passive immunity in Danish dairy calves seems low and does not meet new recommendations. However, applying cut-offs based on radial immunodiffusion to serum IgG concentrations derived from ELISA are not straightforward and determination of new cut-off values for FTPI based on ELISA are recommended.

Background: Bopivirus B is an emerging picornavirus that affects goats in China. This study aimed to establish a TaqMan real-time PCR assay for detecting Bopivirus B and conduct a preliminary survey of infection in six goat farms in Sichuan province, China. Specific primers and a probe targeting the 3D gene of Bopivirus B were designed, and the TaqMan-based real-time PCR assay was successfully established following the optimization of reaction conditions and components. A total of 257 goat fecal samples were collected from six farms in Sichuan and tested using the newly developed method.

Results: The assay demonstrated a linear relationship between 2.73 × 10³ and 2.73 × 10⁹ copies/µL, with a high correlation coefficient (R² = 0.999) and amplification efficiency of 109%. Additionally, the assay exhibited excellent specificity and reproducibility, with a detection limit of 27.3 copies/µL. The field positive rate of Bopivirus B was 100%, and a higher positive rate was observed in diarrheal fecal samples (33.72%) compared to non-diarrheal fecal samples (12.28%, P < 0.005), suggesting a potential association between Bopivirus B and goat diarrhea, with a widespread prevalence in goats in the Sichuan province. Furthermore, ten complete 3D genes sequences of Bopivirus B were obtained, and phylogenetic analysis showed that all Bopivirus B strains in this study were most closely related to two known Chinese Bopivirus strains based on nucleotide sequences of the 3D gene.

Conclusions: This study developed a highly specific, repeatable, and sensitive TaqMan-based real-time PCR assay targeting the 3D gene for Bopivirus B detection, offering a valuable tool for the detection and epidemiological investigation of Bopivirus B. The prevalence of Bopivirus B was widespread in goats in China, with a close association observed between Bopivirus B and goat diarrhea.

Background: Spinal neoplasms are sparsely documented in juvenile dogs. Case reports and small case series have described nephroblastomas, primitive neuroectodermal tumours, gliomas, certain sarcomas, and osteochondromas, but round cell sarcomas have not previously been documented.

Case presentation: This case report describes a 10-week-old female Rottweiler puppy with acute onset of progressive ataxia and pelvic limb lameness. Neurological examination localised a T3-L3 myelopathy and MRI revealed an ovoid, well-marginated mass extending from mid L3 to caudal L4 vertebrae. Post-mortem examination, histopathology, and immunohistochemistry confirmed a round cell sarcoma of extradural origin.

Conclusion: Our case report stresses the importance of performing MRI even in very young individuals with acute progressive signs of spinal cord lesions. Clinicians should include spinal tumours as a differential diagnosis for juvenile canines with spinal neurological signs. Round cell sarcoma should be added to the list of spinal tumours in young dogs.

Background: The health and welfare of pigs used in biomedical research is essential to research quality and compliance with the 3Rs (replacement, reduction, and refinement). Hematological variables are objective markers to quantitatively determine health issues and evaluate physiological differences before and after experimental procedures. There are no recent validated hematologic reference intervals (RIs) published for Danish crossbred Landrace Yorkshire Duroc (LYD) pigs to aid researchers and veterinarians in their decision-making. The objective of this study was to establish hematologic RIs for LYD pigs used for biomedical research. Blood samples were collected from healthy female LYD pigs (35-65 kg) and analyzed using the in-house ProCyte Dx Hematology Analyzer. Means with 90% confidence intervals for lower and upper limits were calculated according to guidelines by the American Society of Veterinary Clinical Pathology.

Results: Inspection of 141 pigs led to 133 blood samples available for analyses after exclusions due to clinical signs of disease, inadequate tube filling or presence of macroscopic clots. Thirty-two samples reported platelet abnormalities and upon further investigation these samples were excluded when calculating RIs for platelets and platelet indices. Other measurements were not affected. The RI for red blood cells, hemoglobin, hematocrit and white blood cells were 5.10-7.00 × 10⁶/µL, 9.36-12.29 g/dL, 30.46-40.47%, and 11.73-25.00 × 10³/µL, respectively.

Conclusions: Our study provides RIs for hematological variables in LYD pigs, revealing significant differences from published RIs of other breeds. These findings highlight the influence of factors like age, breed and health status on measurements, emphasizing the importance of using breed-specific RIs. This research supports the 3Rs, guiding better animal care and enhancing overall research quality.

Background: Lumbosacral transitional vertebra (LTV) is a congenital anomaly in dogs and have been proposed to be associated with cauda equina syndrome (CES) in German Shepherd dogs. This prospective study, including 32 dogs from two breeds, aims to investigate if LTV is associated with lower back pain in dogs. The study compared owners' assessment of their dogs' well-being and clinical evaluation with advanced diagnostic imaging to identify changes that might explain clinical findings.

Results: Dogs with LTV type 2 (57.0%) and with LTV type 3 (70.0%) exhibited mild lower back pain, which was significantly more frequent (P = 0.012) compared to dogs with LTV type 0 and LTV type 1. Advanced diagnostic imaging identified a plausible cause for this pain. Dogs diagnosed with LTV types 2 and 3 with lower back pain tended to be lighter (median 14.50 kg) and younger (median 4.10 years) than breeds typically reported for degenerative lumbosacral stenosis (DLSS). Based on the owners' assessment of their dogs, they considered them pain-free.

Conclusions: The study identified a correlation between LTV types 2 and 3 and lower back pain in these dog breeds. Advanced diagnostic imaging findings confirmed that dogs with these LTV types were more likely to exhibit pathological changes associated with DLSS.

Background: Biosecurity measures are essential for mitigating the risk of pathogen introduction and spread in farms. While standardised tools for monitoring biosecurity implementation exist, they are often not tailored to the specific needs of low and middle income countries (LMICs), where pathogen occurrence and farming practices can be highly variable compared to intensive high income country settings. The aim of our study was to develop a flexible risk assessment tool for evaluating biosecurity practices on small and medium-scale poultry farms in LMICs. The methodology described here allows local experts to adapt the tool to current conditions.

Results: The development process began by combining two existing questionnaires. These were evaluated by nine experts with expertise in diverse farming systems in LMICs. The experts conducted a knowledge aggregation process to assign weights to the different areas and individual questions within the questionnaires. The median scores from the final expert elicitation informed the weighting of questions in the newly developed questionnaire. These weights are adaptable and can be adjusted to reflect population-specific conditions, which may vary in pathogen load and farming practices.

Conclusions: We have developed a flexible biosecurity assessment tool tailored to small-and medium-scaled poultry farms in LMICs. This tool can be used as presented or adapted to local conditions through the input of local experts, allowing for effective and context-specific biosecurity monitoring.

Background: Cellulitis due to infection with clostridia has not been documented in horses in Iceland. However, clostridia are well-known pathogens in Icelandic sheep, which have traditionally shared grazing land with horses. Clostridial infections of equine muscle or subcutis following injection with medicinal products have been described in other countries but have never been reported in Iceland. In this case report, we present the first documented outbreak of subcutaneous clostridial infection in horses in Iceland following subcutaneous injection.

Case presentation: In November 2022, 16 out of 32 horses, that some days earlier had received a subcutaneous injection of Noromectin^® 1% injectable solution, developed clinical signs indicating malignant oedema. The clinical signs included pyrexia, depression, swollen limbs, chest and neck, reluctance to move and dyspnoea, leading to the death or euthanasia of five horses. In addition, one horse was found dead with no previously noted clinical signs. Necropsy of one of the five horses revealed severe, acute cellulitis in the neck region, as well as lymphadenitis in regional lymph nodes. Abscesses, some with subsequent spontaneous drainage of seropurulent material, were observed at the presumed injection site on eight surviving horses approximately 2 weeks post-injection. Bacterial culture of samples from the necropsied horse and from abscesses from three surviving horses yielded the growth of C. septicum. Analysis of water samples from the pasture where the herd was kept also revealed the presence of C. septicum. Whole genome sequencing suggested that the isolates from the diseased horses contained the same C. septicum strain, whereas the strain isolated from the water samples differed from the disease-causing isolates.

Conclusions: Clinical signs compatible with serious subcutaneous C. septicum infection were seen in over half of 32 horses injected with an ivermectin product, with the subsequent death of six of the horses. In the absence of other obvious sources, the outbreak suggests that C. septicum spores on the skin of these horses were introduced under the skin when they were injected. Such infections have not been reported in Iceland, although ivermectin products formulated for subcutaneous injection have been widely used for more than 30 years. The outbreak warrants further investigation into C. septicum in the environment of grazing horses in Iceland.

Background: Information on indirect contacts (e.g. contact with visitors and non-porcine species on farms, shared staff and equipment, contact with trucks) is often poorly recorded even though it constitutes a risk in terms of disease transmission. The aim of the present study was to quantify the number of indirect contacts and associated biosecurity measures in Danish pig herds. A questionnaire survey was conducted among both veterinarians and pig producers in Denmark during 2022-2023. The veterinary questionnaire resulted in 143 answers, representing the Veterinary Health Advisory Service contracts for 53% of non-hobby pig farms. The questionnaire for the pig producers resulted in 373 valid responses and a final response rate of 18%. The results from the veterinary questionnaire provide information on veterinary contacts between pig farms and also estimates on the agreement between registration data and real-life observations.

Results: The questionnaire for veterinarians stated that the majority of veterinarians specialized within pig practice would visit > 3 pig farms per day, with pig farms being located with an average distance between the farms of 15 km. The veterinarians presumed wind, movement of pigs and trucks transporting pigs to be the main routes of PRRS infection. The questionnaire for pig producers provides updated data on indirect contacts (e.g. contact with visitors and non-porcine species on farms, sharing of staff and equipment, procedures for purchase/delivery of pigs and contact with trucks) stratified in terms of farm type and production type. Among respondents, 10% of the pig producers shared staff, while 2% shared equipment (washing robots) with other farms, excluding farms in a joint operation. When purchasing gilts, 70% of the participating pig producers introduced gilts in line with recommendations for strict quarantine for a minimum of 42 days. The delivery of the pigs varied, depending on the type of pigs being delivered: finishers were typically delivered for slaughter through delivery facilities into a (usually empty) slaughterhouse truck, while sows for slaughter were typically delivered by means of a delivery truck offsite into a slaughterhouse truck (usually with other pigs on board).

Conclusion: Since the inclusion of indirect contacts in disease spread models relies on valid data, the present study provided valuable data regarding the frequencies and biosecurity measures of indirect contacts between Danish pig herds, which may be useful in the parametrization of computational epidemiological models.