Low MRSA prevalence in horses at farm level

Background: In Europe, methicillin-resistant Staphylococcus aureus (MRSA) belonging to the clonal complex (CC) 398 has become an important pathogen in horses, circulating in equine clinics and causing both colonization and infection. Whether equine MRSA is bound to hospitals or can also circulate in the general horse population is currently unknown. This study, therefore, reports the nasal and perianal MRSA screening of 189 horses on 10 farms in a suspected high prevalence region (East-and West-Flanders, Belgium). Results: Only one horse (0.53%) from one farm (10%) tested positive in the nose. It carried a spa type t011-SCCmecV isolate, resistant to beta-lactams and tetracycline, which is typical for livestock-associated MRSA CC398. Conclusion: In the region tested here, horses on horse farms seem unlikely to substantially contribute to the large animal associated ST398 MRSA reservoir present at intensive animal production units

Cardiovascular effects of a bolus of enoximone with or without a constant rate infusion of dobutamine in isoflurane-anaesthetized ponies

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Effects of dobutamine on cardiovascular function and respiratory gas exchange after enoximone in isoflurane-anaesthetized ponies

Objective To evaluate the combined effects of enoximone and dobutamine on the cardiovascular system and respiratory gas exchange in isofluraneanaesthetized ponies. Study design Prospective, randomized, experimental study. Animals Six ponies (286 +/- 52 kg), aged 5.0 +/- 1.6 years. Methods After sedation (romifidine 80 mu g kg(-1)), anaesthesia was induced with midazolam (0.06 mg kg(-1)) and ketamine (2.2 mg kg(-1)) and maintained with isoflurane in oxygen. The ponies were ventilated to maintain eucapnia. After 90 minutes (= T0), enoximone alone (0.5 mg kg(-1)) ( E) or enoximone, followed by a constant rate infusion of dobutamine (0.5 mu g kg(-1) minute(-1)) (ED) for 120 minutes, was administered. Each pony received both treatments in a crossover trial, with at least 2 weeks between treatments. Heart rate (HR), cardiac output (CO), stroke volume (SV), right atrial (RAP), systolic ( SAP), diastolic (DAP) and mean arterial pressure ( MAP), blood gases, systemic vascular resistance (SVR), oxygen delivery (DO2) and several respiratory gas exchange variables were measured before treatment and until T120. Statistical analysis was based on a mixed model with treatment, time and their interaction as fixed categorical effects, pony as random effect, comparing treatments globally (alpha = 0.05) and at specific timepoints (Bonferroni-adjusted alpha = 0.00625). Results Compared to enoximone alone, ED treatment produced an increase in HR, CO, SV, RAP, SAP, DAP, MAP, packed cell volume (PCV) and DO2. The difference was significant from T60 to T120 (except at T80) for HR, throughout the observational period for CO, SAP, MAP, PCV and DO2, from T40 to T120 for DAP, at T10, T60, T80 and T120 for SV and at T10 and T20 for RAP. Overall decreases occurred in SVR and dead space ventilation (V-D/V-T). V-D/V-T was lower at T20 and from T80 to T120. Venous oxygen saturation was increased from T60 onwards. Conclusions and clinical relevance The results suggest that enoximone and dobutamine have additive cardiovascular effects and reduce V-D/V-T in isoflurane-anaesthetized ponies

Cardiovascular effects of enoximone in isoflurane anaesthetized ponies

Objective: Enoximone is a phosphodiesterase III inhibitor frequently used to improve cardiac output (CC) in man. As the use of enoximone has not been reported in horses, the effects of this inodilator were examined in isoflurane anaesthetized ponies. Study design: Prospective, randomised, experimental study. Animals: Six healthy ponies, weighing 286 (212367) 52 kg, aged 5.0 +/- 1.6 years (4-6.5). Methods: After sedation with romifidine [80 mu g kg(-1) intravenously (IV)], general anaesthesia was induced with midazolam (0.06 mg kg(-1) IV) and ketamine (2.2 mg kg(-1) IV) and maintained with isoflurane in oxygen (Et Iso 1.7%). The ponies were ventilated to maintain eucapnia (PaCO2 4.66-6.00 kPa). Each pony was anaesthetized twice with an interval of 3 weeks; receiving enoximone 0.5 mg kg(-1) IV (E) or saline (S) 90 minutes postinduction. Heart rate (HR), arterial (AP) and right atrial pressure (RAP) were measured before treatment, every 5 minutes between TO (treatment) and T30 and then every 10 minutes until T120. Cardiac output measurements (lithium dilution technique) and blood gas analysis (arterial and central venous samples) were performed before T0 and at T5, T10, T20, T40, T60, T80, T100 and T120. Stroke volume (SV), systemic vascular resistance (SVR), venous admixture (Qs/Qt) and oxygen delivery DO2 were calculated. Results: Enoximone induced significant increases in FIR, CO, SV, Qs/Qt and DO2 and a significant decrease in RAP. No significant differences were detected for AP, SVR and blood gases. No cardiac arrhythmias or other side effects were observed. Conclusions and clinical relevance: The present results suggest that in isoflurane anaesthetized ponies, enoximone has beneficial effects on CO and SV without producing significant changes in blood pressure. Despite an increase in Qs/Qt, hO, to the tissues was improved