René van den Hoven

Diagnostic value of the neutrophil myeloperoxidase index in horses with systemic inflammation.

The myeloperoxidase index (MPXI) was investigated as a diagnostic indicator of systemic inflammation in a retrospective study using data from 859 hospitalised horses. A reference interval of 8.5-10.4 for the MPXI was established. In horses with systemic inflammatory response syndrome (SIRS), the MPXI was significantly lower than in healthy horses, those with localised inflammation and those with sepsis. The MPXI in horses with sepsis was also significantly lower than in healthy animals and those with localised inflammation. Horses in the SIRS group with leucopenia, white blood cell (WBC) count within the reference interval (WRI) or leucocytosis had significantly lower MPXIs than healthy horses, those with localised inflammation and those with sepsis in the same WBC count subgroups. In horses with sepsis and WBC count WRI, the MPXI was significantly lower than in healthy horses or those with localised inflammation. MPXI is a useful complementary tool to identify horses with systemic inflammation, especially if they have WBC counts WRI.

Measurement of tidal volume using Respiratory Ultrasonic Plethysmography in anaesthetized, mechanically ventilated horses

OBJECTIVE To compare tidal volume estimations obtained from Respiratory Ultrasonic Plethysmography (RUP) with simultaneous spirometric measurements in anaesthetized, mechanically ventilated horses. STUDY DESIGN Prospective randomized experimental study. ANIMALS Five experimental horses. METHODS Five horses were anaesthetized twice (1 week apart) in random order in lateral and in dorsal recumbency. Nine ventilation modes (treatments) were scheduled in random order (each lasting 4 minutes) applying combinations of different tidal volumes (8, 10, 12 mL kg(-1)) and positive end-expiratory pressures (PEEP) (0, 10, 20 cm H(2)O). Baseline ventilation mode (tidal volume=15 mL kg(-1), PEEP=0 cm H(2)O) was applied for 4 minutes between all treatments. Spirometry and RUP data were downloaded to personal computers. Linear regression analyses (RUP versus spirometric tidal volume) were performed using different subsets of data. Additonally RUP was calibrated against spirometry using a regression equation for all RUP signal values (thoracic, abdominal and combined) with all data collectively and also by an individually determined best regression equation (highest R(2)) for each experiment (horse versus recumbency) separately. Agreement between methods was assessed with Bland-Altman analyses. RESULTS The highest correlation of RUP and spirometric tidal volume (R(2)=0.81) was found with the combined RUP signal in horses in lateral recumbency and ventilated without PEEP. The bias ±2 SD was 0±2.66 L when RUP was calibrated for collective data, but decreased to 0±0.87 L when RUP was calibrated with individual data. CONCLUSIONS AND CLINICAL RELEVANCE A possible use of RUP for tidal volume measurement during IPPV needs individual calibration to obtain limits of agreement within ±20%.

Estimated prevalence of the GYS-1 mutation in healthy Austrian Haflingers

The aim of this study was to determine the occurrence and frequency of a mutation in the gene coding for skeletal muscle glycogen synthase type 1 (GYS-1), which is the cause of equine polysaccharide storage myopathy (PSSM) type 1 in a population of 50 Haflingers. GYS-1 genotyping of 50 Haflingers was performed with a validated restriction fragment length polymorphism (RFLP) assay. The second aim was to compare resting and post-exercise muscle enzyme activities as well as parameters of glucose metabolism in blood between horses with and without the mutation. Nine of the 50 Haflingers were identified to be heterozygous for the mutation (HR). None was homozygous (HH). The estimated HR prevalence was 18 per cent in this herd. Mean aspartate aminotransferase (AST) activity at rest and mean creatine kinase and AST activity after exercise were significantly higher in HR compared with RR (homozygote normal) horses. No significant differences could be found in the other parameters.

Equine multinodular pulmonary fibrosis (EMPF): Five case reports.

Equine multinodular pulmonary fibrosis (EMPF), a progressive fibrosing interstitial lung disease has been associated with gammaherpesviruses. This case series describes five horses with EMPF. Three of the horses (two in Hungary, one in the Czech Republic) were diagnosed with EMPF ante mortem. They presented with typical clinical signs of EMPF including dyspnoea and weight loss. Arterial blood gas analysis revealed hypoxaemia. Blood work showed signs of inflammation like neutrophilia and hyperfibrinogenaemia. An endoscopic examination of the respiratory tract including cytology and culture of tracheobronchial secretion and bronchoalveolar lavage were performed, revealing secondary bacterial infection in one case. A suspected diagnosis of EMPF was made on the basis of a positive EHV-5 PCR from bronchoalveolar lavage and the findings of thoracic radiographs and ultrasound examination. In one case the diagnosis was confirmed by lung biopsy. All horses died or had to be euthanised despite treatment. Two horses (from Austria) were diagnosed with EMPF post mortem. They not only had EMPF but also concurrent other diseases which seemed to be associated with immunosuppression. Three horses showed the discrete form and two horses the diffuse form of EMPF. EHV-5 DNA was identified in lung tissue of all horses by PCR.

Influence of the collection and oxygenation method on quantitative bacterial composition in bronchoalveolar lavage fluid samples from healthy dogs

The purpose of the study was to evaluate the effects on quantitative and qualitative microbial content of endoscopic bronchoalveolar lavage fluid (BALF) in healthy dogs using a laryngeal mask airway (LMA). It was hypothesised that oropharyngeal protection might prevent contamination of BALF with oropharyngeal microflora. Ten healthy Beagle dogs were randomly assigned to two groups and underwent endoscopic BAL on two occasions, either via an open unprotected oropharynx with oxygen supply provided via a nasal catheter (NT) or through a sterile LMA. For the second sampling, groups were switched. BALF analysis included quantitative microbial culture, nucleated cell counts and cytology. The mean (+/-SD) number of colony forming units (CFU)/mL found in the BALF using the LMA was 25,610+/-22,943 in the right lung (RL) and 22,510+/-18,779 in the left (LL). With the NT technique, the figures were 21,068+/-19,375 for the RL and 16,060+/-15,523 for the LL, respectively. Nucleated cell counts/microL were 691.0+/-181.6 (RL) and 734.0+/-171.6 (LL) for LMA, and 772.0+/-251.0 (RL) and 748+/-163.2 (LL) for NT. No significant differences were detected either in the number of CFU/mL or in the diversity of bacterial species with the two methods. A significant increase in BALF bacterial counts (with reduced species diversity) was observed on the second compared to the first sampling regardless of the method used. Protection of the oral cavity and oropharynx using an LMA had no significant influence on BALF bacterial counts. The findings suggest that with careful endoscope insertion, the risk of contamination of BALF by resident and transient oropharyngeal microflora can be negligible.

In vitro validation of a new respiratory ultrasonic plethysmograph

OBJECTIVE The in-vitro validation of a novel Respiratory Ultrasonic Plethysmography (RUP) system designed to detect circumference changes of rib cage and abdominal compartments in large and small animals. STUDY DESIGN Experimental in vitro study. METHODS The experimental system includes two compliant fluid-filled rubber tubes functioning as ultrasonic waveguides. Each has an ultrasonic transmitter and a detector at the opposing ends. Sensor length can be individually adapted in the range of 0.15-2 m. Data are downloaded to a computer at a sampling rate of 10 or 100 Hz. Measurements have a resolution of 0.3 mm. Baseline stability, linearity and repeatability were investigated with dedicated experiments. The base line drift was tested measuring a fixed distance for 2 hours continuously and then 18 hours later. A hand-operated horse thorax dummy (elliptically shaped, circumference 1.73 m) was used to compare waveforms of RUP with a respiratory inductive plethysmograph (RIP). The electromagnetic interference was tested by approaching metallic objects. RESULTS Baseline drift and repeatability (10 repeated steps of 1.6% and 6.6% elongations and contractions) were within ± 0.3 mm. The response of the system for tube stretching up to 11% of total length was linear with a coefficient of determination for linearity of 0.998. In contrast to RIP, electromagnetic interference could not be observed with RUP. CONCLUSIONS AND CLINICAL RELEVANCE The low baseline drift and the lack of electromagnetic interference favours the use of RUP compared to an RIP device when studying the breathing pattern and end expiratory lung volume changes in conscious and anaesthetized animals.

Serological evidence of West Nile virus infection in the horse population of northern Serbia

INTRODUCTION This study was conducted to evaluate the seroprevalence of West Nile virus (WNV) in the horse population of northern Serbia. Furthermore, it aimed to provide insight and an updated overview on the circulation of this re-emerging pathogen in this part of southeastern Europe. At the time of manuscript preparation, no clinical cases of WNV infection in horses were reported in this area. METHODOLOGY Between 2007 and 2011, a total of 252 equine serum samples were collected from seven different locations in northern Serbia. The presence of WNV-reactive IgG antibodies was examined by using commercial and in-house ELISAs. Selected ELISA-positive samples were re-tested by a WNV lineage 2 plaque reduction neutralization test 90% (PRNT-90). RESULTS In 28.6% of the 252 tested equine serum samples antibodies against WNV were detected. The results obtained with the in-house ELISA corresponded to the outcome of the commercial kit in 90% of the samples. All selected WNV antibody ELISA-positive samples were confirmed by PRNT-90 with neutralizing antibody titers of 1:23 to > 1:512. CONCLUSION This study confirms the circulation of WNV in northern Serbia. No striking regional differences in seroprevalences were identified suggesting WNV circulation also in other parts of Serbia. Distances between wetlands or forests and stud farms do not appear to have an influence on WNV seroprevalence.

Retrospective evaluation of 155 adult equids and 21 foals with tetanus from Western, Northern, and Central Europe (2000–2014). Part 2: Prognostic assessment

OBJECTIVE To identify prognostic variables for adult equids and foals with tetanus. DESIGN Multicenter retrospective study (2000-2014). SETTING Twenty Western, Northern, and Central European university teaching hospitals and private referral centers. ANIMALS One hundred fifty-five adult equids and 21 foals with tetanus. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Variables from history and clinical examination were statistically compared between survivors and nonsurvivors (adults: 49 survivors, 85 nonsurvivors; foals: 7 survivors, 10 nonsurvivors). Cases euthanized for financial reasons were excluded. Mortality rates in adults and foals were 68.4% and 66.7%, respectively. Variables associated with survival in adults included: standing, normal intestinal sounds and defecation, voluntarily drinking, eating soft or normal food, lower heart and respiratory rates, high base excess on admission, longer diagnosis time, treatment and hospitalization delay, and mild severity grade. Variables associated with death included: anorexia, dysphagia, dyspnea, low blood potassium concentration on admission, moderate and severe disease grading, development of dysphagia, dyspnea, recumbency and seizures during hospitalization, treatment with glycerol guaiacolate, intravenous fluids, and intravenous glucose solutions. Variables associated with survival in foals included standing on admission, voluntarily eating soft food and drinking, older age, and longer hospitalization delay. Outcome was not different between different tetanus antitoxin (TAT) dosages, although there was a trend of increasing survival rate with increasing TAT dosages. Cases with appropriate vaccination prior to development of tetanus were rare, but had improved outcome and shorter hospitalization. CONCLUSIONS Prognosis for equine tetanus is poor with similar outcome and prognostic factors in foals and adults. The prognostic assessment of cases with tetanus provides clinicians with new evidence-based information related to patient management. Several prognostic indicators relate to the ability to eat or drink, and more severe clinical signs relate to poor outcome. Increasing intravenous dosages of TAT has no significant effect on outcome, but the positive trend identified may support a recommendation for high intravenous TAT dosages. Further evaluation is warranted.

Retrospective evaluation of 155 adult equids and 21 foals with tetanus in Western, Northern, and Central Europe (2000–2014). Part 1: Description of history and clinical evolution

OBJECTIVE To describe clinical data of hospitalized adult equids and foals with tetanus. DESIGN Multicenter retrospective study (2000-2014). SETTING Twenty Western, Northern, and Central European university teaching hospitals and private referral centers. ANIMALS One hundred fifty-five adult equids (>6 months) and 21 foals (<6 months) with tetanus. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Information on geographic, annual and seasonal data, demographic- and management-related data, clinical history, clinical examination and blood analysis on admission, complications, treatments, and outcomes were described and statistically compared between adults and foals. The described cases were often young horses. In 4 adult horses, tetanus developed despite appropriate vaccination and in 2 foals despite preventive tetanus antitoxin administration at birth. Castration, hoof abscesses, and wounds were the most common entry sites for adults; umbilical cord infections and wounds for foals. Stiffness was the commonest observed initial clinical sign. Blood analyses frequently revealed an inflammatory response, hemoconcentration, muscle damage, azotemia, negative energy balance, liver damage, and electrolyte and acid base disturbances. Common complications or clinical signs developing during hospitalization included dysphagia, dyspnea, recumbency, hyperthermia, seizures, hyperlipemia, gastrointestinal impactions, dysuria, and laryngeal spasms. Cases were supported with wound debridement, antimicrobial treatment, tetanus antitoxin, muscle spasm and seizure control, analgesia, anti-inflammatory drugs, fluid therapy, and nutritional support. Mortality rates were 68.4% in adult horses and 66.7% in foals. Foals differed from adult horses with respect to months of occurrence, signalment, management-related data, potential causative events, clinical signs on admission, blood analysis, complications, and severity grades. CONCLUSIONS This is the first study that rigorously describes a large population of equids affected by tetanus. The information provided is potentially useful to clinicians for early recognition and case management of tetanus in adult horses and foals. Tetanus affects multiple organ systems, requiring broad supportive and intensive care. Neonatal and adult tetanus in the horse should be considered as distinct syndromes, as in human medicine.