Influence of age of horse on results of quantitative electromyographic needle examination of skeletal muscles in Dutch Warmblood horses

OBJECTIVE: To determine the influence of age on results of quantitative analysis of electromyographic (EMG) needle examination in the subclavian, triceps, and lateral vastus muscles of Dutch Warmblood horses. ANIMALS: 7 healthy young Dutch Warmblood horses (range, 13 to 18 months old), 7 healthy adult Dutch Warmblood horses (range, 4 to 10 years old), and 7 healthy elderly Dutch Warmblood horses (range, 18 to 21 years old). PROCEDURE: An EMG needle examination was performed to evaluate insertional activity, spontaneous activity, and motor unit action potential (MUAP) variables. Although all horses were conscious, young horses were sedated prior to examination. RESULTS: Mean insertional activity in young horses was significantly lower than in elderly horses. Pathologic spontaneous activity was rarely found in young and adult horses but was frequently evident in all muscles in all elderly horses. The MUAP duration and amplitude were significantly lower in all muscles of young horses, compared with values for adult and elderly horses. The MUAP duration and number of phases and turns were significantly lower in adult horses than in elderly horses. Group differences for percentages of polyphasic and complex MUAPs were also found. The 95% confidence intervals for MUAP duration, MUAP amplitude, and number of phases and turns for the subclavian, triceps, and lateral vastus muscles were significantly lower in young horses than in adult or elderly horses. CONCLUSIONS AND CLINICAL RELEVANCE: Age of the horse being examined should be considered when EMG examination is performed.     

Electromyographic changes of motor unit activity in horses with induced hypocalcemia and hypomagnesemia

OBJECTIVE: To determine whether electromyographic abnormalities are evident in skeletal muscles in horses with induced hypocalcemia and hypomagnesemia. ANIMALS: 7 healthy adult Dutch Warmblood horses. PROCEDURES: Electromyographic examination was performed in the lateral vastus, triceps, and subclavian muscles before and after IV infusion of EDTA. An initial dose (mean +/- SD, 564+/-48 ml) of a 10% solution of sodium EDTA was administered IV during a period of 21+/-73 minutes to establish a blood concentration of ionized calcium of approximately 0.5 mmol/L. Average rate of EDTA infusion to maintain ionized calcium at this concentration was 6.6 ml/min. RESULTS: Mean blood concentrations of ionized calcium and magnesium were 1.39+/-0.06 and 0.84+/-0.09 mM, respectively before EDTA infusion; after EDTA infusion, concentrations were 0.48+/-0.05 and 0.44+/-0.20 mM, respectively. This state induced positive waves; fibrillation potentials; doublets, triplets, and multiplets; complex repetitive discharges; and neuromyotonia. Analysis of motor unit action potentials (MUAP) after EDTA infusion revealed an increase in prevalence of polyphasic and complex MUAP in all muscles. CONCLUSIONS AND CLINICAL RELEVANCE: None of the horses had classical signs of hypocalcemia and hypomagnesemia. In contrast, all horses had spontaneous activity in the measured muscles indicative of nerve hyperirritability. Calcium and magnesium deficits appear to have consequences, which may be subclinical, affecting functions of the neuromuscular system. This is of interest for equestrian sports in which hypocalcemia and hypomagnesemia are expected, such as during endurance rides.     

Quantitative analysis of motor unit action potentials in the subclavian muscle of healthy horses

OBJECTIVE: To evaluate the application of analysis of motor unit action potentials (MUAP) in horses and to obtain values of MUAP for the subclavian muscle of horses. ANIMALS: 10 healthy adult Dutch Warmblood horses. PROCEDURE: Electromyographic examination of the subclavian muscle in conscious nonsedated horses was performed to evaluate insertional activity, spontaneous activity, MUAP variables, and recruitment patterns. Muscle and body temperatures were measured at the beginning and end of the procedure. Amplitude, duration, number of phases, and number of changes in direction (ie, turns) for all representative MUAP were analyzed to determine values for this muscle in this group of horses. RESULTS: Mean +/- SD duration of insertional activity was 471.7 +/- 33.45 milliseconds. Mean MUAP amplitude in the examined horses was 379 RV (95% confidence interval [CI], 349 to 410 microV). Mean MUAP duration of the subclavian muscle was 727 milliseconds (95% CI, 6.84 to 7.71 milliseconds). Mean number of phases was 2.9, and mean number of turns was 3.0. Prevalence of polyphasic MUAP defined as MUAP with > 4 phases, was 77%. Number of MUAP that had > 5 turns was 2.4%. Satellite potentials were found in 1.0% of the MUAP CONCLUSIONS AND CLINICAL RELEVANCE: This study revealed that electromyography including MUAP analysis can be performed in horses, and values for the subclavian muscle in healthy adult horses can be obtained. Analysis of MUAP could be a valuable diagnostic tool for use in discriminating between myogenic and neurogenic problems in horses.     

Temporary disturbance of actin stress fibers in swine kidney cells during pseudorabies virus infection

Rounding and loosening of cells is a consequence of infection with pseudorabies virus (PrV), both in vitro and in vivo. These changes in the normal structure of the cell may be the result of cytoskeletal changes. Immunofluorescence staining of actin filaments and microtubule bundles was performed to examine whether PrV induces a reorganization of these cytoskeletal components in infected swine kidney (SK) cells. Every 2h until 12h post-inoculation (p.i.), cells were washed in cytoskeleton stabilizing buffer (CSB), fixed with paraformaldehyde and washed again with CSB. Cells were permeabilized with a 1/1000 dilution of Triton X-100 and actin filaments were stained by incubating cells with phalloidin-Texas Red. Staining of microtubules was done by incubating the cells subsequently with mouse monoclonal anti-alpha-tubulin and goat anti-mouse IgG-FITC. During the course of infection, actin fibers of SK cells were rearranged in the following sequence: (1) disappearance of thick actin stress fibers between 4 and 6h p.i., (2) complete loss of stress fibers between 6 and 8h p.i., and (3) reappearance of thin stress fibers starting from 10h p.i. In contrast to herpes simplex virus 1 (HSV1) or equine herpesvirus 1 (EHV1), PrV infection did not induce changes in the cellular microtubule network. PrV infection induces a temporary disassembly of actin stress fibers.     

Dysostosis Enchondralis of the Ulnar Bone in the Basset Hound

Ninety-four Basset Hounds were examined for the clinical features, the radiographical changes and the nutritional and hereditary possibilities connected with the development of decreased longitudinal growth of the ulnar bone. In six puppies the possibility was examined of the development of the disease being due to overloading of the foreleg. Ten of the dogs were examined for gross pathology and 4 by histology post mortem.Clinical symptoms and radiographical changes were not seen until the age of 31/2 months. In all cases there were broadening of the joint space in the elbow joint and degeneration of the articular cartilage at the semilunar notch. An abnormally broad and irregular growth plate was seen in the affected young dogs, and histology revealed obvious abnormalities in the growth plate located in the zone of resting cartilage indicating degenerative disturbances in the cartilage. There were no signs of rickets, and it was not possible to demonstrate that the disease was caused by misleading.It is concluded that the disease corresponds to similar anomalies found in the other chondrodystrophic breeds of dogs, and it is suggested that the decreased growth of the ulnar bone may be hereditary.     

How Can Participatory Forest Management Cooperatives be Successful in Forest Resources Conservation? An Evidence From Ethiopia

ABSTRACT

In many parts of the world, community-based approaches to forest management have been evolving after recognizing that the top-down approach impedes conserving forests effectively. In Ethiopia also, local communities have been involved in participatory forest management (PFM) arrangements for better conservation of forest resources. However, the achievements in improving forest conservation outcomes have been mixed, while some PFMs are successful, others are not. Using data collected from 42 PFM cooperatives from Metema and Quara districts in Amhara dry forest region of Ethiopia, this study seeks to examine the variables that explain the variations in the performances of PFM cooperatives in forest conservation. The study has found that the performance of the PFM cooperatives depends on the key attributes of users, physical resources, and institutions and these attributes explain best for the success of PFMs. Therefore, the study suggests that these attributes along with the external factors like government policy must be given due importance while designing PFM arrangement. Moreover, just to highlight the impact of the external factors, the government policy like the resettlement program must be reconsidered; while the expansion of trade and infrastructure must be encouraged in order to strengthen the performance of PFMs and achieve forest conservation.     

Large-scale identification of rodenticide resistance in Rattus norvegicus and Mus musculus in the Netherlands based on Vkorc1 codon 139 mutations

BACKGROUND

Resistance to rodenticides has been reported globally and poses a considerable problem for efficacy in pest control. The most-documented resistance to rodenticides in commensal rodents is associated with mutations in the Vkorc1 gene, in particular in codon 139. Resistance to anticoagulant rodenticides has been reported in the Netherlands since 1989. A study from 2013 showed that 25% of 169 Norway rats (Rattus norvegicus) had a mutation at codon 139 of the Vkorc1 gene. To gain insight in the current status of rodenticide resistance amongst R. norvegicus and house mice Mus musculus in the Netherlands, we tested these rodents for mutations in codon 139 of the Vkorc1 gene. In addition, we collected data from pest controllers on their use of rodenticides and experience with rodenticide resistance.

RESULTS

A total of 1801 rodent samples were collected throughout the country consisting of 1404 R. norvegicus and 397 M. musculus. In total, 15% of R. norvegicus [95% confidence interval (CI): 13–17%] and 38% of M. musculus (95% CI: 33–43%) carried a genetic mutation at codon 139 of the Vkorc1 gene.

CONCLUSION

This study demonstrates genetic mutations at codon 139 of the Vkorc1 gene in M. musculus in the Netherlands. Resistance to anticoagulant rodenticides is present in R. norvegicus and M. musculus in multiple regions in the Netherlands. The results of this comprehensive study provide a baseline and facilitate trend analyses of Vkorc1 codon 139 mutations and evaluation of integrated pest management (IPM) strategies as these are enrolled in the Netherlands. © 2022 The Dutch Pest and Wildlife. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Can the use of antimicrobials in adult equine patients with acute colitis be justified in the era of antimicrobial stewardship?

The use of antimicrobials in adult horses with acute colitis is controversial and clear antimicrobial guidelines are lacking. It is generally accepted that antimicrobials should be reserved for patients with specific bacterial enterocolitis such as Neorickettsia risticii or Clostridium difficile; however, in practice, horses show similar clinical signs independently of the underlying aetiology. The clinician is therefore often confronted with the dilemma of rapid initiation of treatment to avoid mortality vs. delayed and selective targeted antimicrobial treatment based on faecal diagnostic testing. The risk of antibiotic associated diarrhoea and the emergence of antimicrobial resistance are other important considerations.     

Hemostatic biomarkers in dogs with chronic congestive heart failure

BACKGROUND: Chronic congestive heart failure (CHF) in humans is associated with abnormal hemostasis, and abnormalities in hemostatic biomarkers carry a poor prognosis. Alterations in hemostatic pathways can be involved in the pathogenesis of CHF in dogs, and microthrombosis in the myocardium could contribute to increased mortality. HYPOTHESIS: That plasma concentration or activity of hemostatic biomarkers is altered in dogs with CHF and that these factors predict mortality. ANIMALS: Thirty-four dogs with CHF caused by either dilated cardiomyopathy (DCM, n=14) or degenerative valvular disease (CDVD, n=20) compared with 23 healthy age-matched control dogs were included in this study. Dogs with CHF were recruited from 2 referral cardiology clinics, and control dogs were owned by friends or colleagues of the investigators. METHODS: Clinical examination and echocardiography were performed in all dogs. Plasma fibrinogen and D-dimer concentrations, antithrombin and protein C activity, and thrombin-antithrombin complex (TAT) were measured in all dogs. RESULTS: Dogs with CHF had significantly higher fibrinogen (P = .04), D-dimer (P = .002), and TAT concentration (P < .0001), lower antithrombin (P < .0001) and protein C activity (P < .001) compared with control dogs. None of the hemostatic biomarkers were associated with risk of death. CONCLUSIONS AND CLINICAL IMPORTANCE: There is evidence of a procoagulant state in dogs with CHF. The lack of predictive value for survival might be due to the small number of dogs examined. Further studies are necessary to investigate the presence and importance of microthrombosis in dogs with CHF.     

Temporal variation and high-resolution spatial heterogeneity in soil CO2 efflux in a short-rotation tree plantation

Soil CO2 efflux (SR) is the second largest carbon flux on earth. We investigated the driving factors of the seasonal change and short-distance spatial variation in SR in a short-rotation plantation of willow (Salix viminalis Orm). Total annual SR ranged from 723 to 1149 g Cm(-2) year(-1). Both an exponential and a logistic model were fitted to the data, with soil temperature at a depth of 5 cm as the independent variable. The R2 values for individual sampling points ranged from 0.83 to 0.95 and from 0.85 to 0.93 for the exponential and logistic models, respectively, indicating that soil temperature largely determined the seasonal variation in SR. Modeled soil SR at 10 degrees C ranged from 1.22 to 1.95 micromol m(-2) s(-1), whereas modeled annual Q(10) values were between 3.31 and 6.13. These high Q(10) values were attributed to the absence of drought during the study in 2005. When the coefficients of the general SR models were replaced by linear dependencies on soil and vegetation-related characteristics, the resulting spatially explicit exponential and logistic SR models explained 85 and 86%, respectively, of the variability within the dataset. The analysis indicated that soil carbon concentration, leaf area index, soil pH and root biomass caused differences in SR at the short distances considered in this study. However, incorporating information on variables considered to account for spatial variability in the model did not result in a higher R2 compared with a simple temperature function. When the general SR models were applied to independent datasets from the same plantation, the logistic model provided a better fit than the exponential model when drought occurred. Drought greatly reduced the annual Q(10) values of SR.