E. Muylle

Protection of just weaned pigs against infection with F18+Escherichia coli by non-immune plasma powder

The anti-colonization effect of porcine plasma powder against experimentally induced postweaning diarrhoea and oedema disease in just weaned piglets was examined. Piglets were infected with an Escherichia coli strain expressing F18ac fimbriae and producing SLTIIv- and LT-toxins. Reduced fecal excretion of the challenge strain and protection against clinical symptoms was obtained by daily supplementation of the feed with either 90 or 45 g of plasma powder. However, the piglets receiving 90 g of plasma powder a day showed diarrhoea and reduced weight gain compared to the piglets receiving 45 g of plasma powder a day. The diarrhoea was attributed to biogenic amines released from excessive protein in the diet.

The influence of the administration of sow's milk on the post-weaning excretion of hemolytic E. coli in the pig.

The postweaning excretion rate of hemolyticE. coli was determined in piglets from herds affected with edema disease and on control farms. No distinct difference in rate of excretion was observed. A split litter trial was set up to evaluate the importance of sows milk in the postweaning rise of fecal hemolyticE. coli. 525 ml of sows milk a day, mixed with the feed, completely inhibited that postweaning rise, even after oral challenge with a pathogenic strain.

Evaluation of the nebulisation of sodium ceftiofur in the treatment of experimental Pasteurella haemolytica bronchopneumonia in calves

Severe acute bronchopneumonia was induced in 24 conventional Friesian Holstein calves by inoculating them intratracheally with Pasteurella haemolytica type A1. Twelve of the calves were treated intramuscularly with sodium ceftiofur and 12 were treated with an aerosol of sodium ceftiofur. The mortality rate in the group of calves treated with the aerosol was significantly lower, and their clinical and haematological parameters returned to normal significantly faster than in the calves treated intramuscularly.

Intracardiac overdrive pacing as a treatment of atrial flutter in a horse

A five-year-old warmblood mare with atrial fibrillation was treated with quinidine sulphate. The atrial rhythm changed to atrial flutter and, because there were toxic effects, the treatment was discontinued. Seven months after the occurrence of the atrial flutter, treatment with a rapid atrial pacing technique restored a normal sinus rhythm. One year after the pacing therapy the horse was still in sinus rhythm and had been brought back into training.

THE USE OF NON-IMMUNE PLASMA POWDER IN THE PROPHYLAXIS OF NEONATAL ESCHERICHIA COLI DIARRHOEA IN CALVES

The protective use of plasma powder from cattle and swine against experimentally induced neonatal E. coli diarrhoea in colostrum‐deprived calves was examined. Diarrhoea was induced with a strain expressing F5+ fimbriae and a strain expressing F17+ fimbriae. In all groups supplemented with bovine plasma powder, diarrhoea and fever were less severe than in the control groups. For the groups infected with the F5+ E. coli strain, a reduction in excretion of the challenge strain by 2–4 orders of magnitude and by 1–2 orders of magnitude was seen when supplemented with bovine plasma powder at a dose of 25 g/l milk and 10 g/l milk, respectively. The bovine plasma powder showed also beneficial effects in the F17+ infected groups. No mortality, no septicaemia and no severe clinical signs were observed. Concerning the excretion of the E. coli F17+ strain in the faeces, no significant difference with the control group was found. Swine plasma powder showed little beneficial effect on E. coli diarrhoea in calves in this study.

Pulmonary driving pressure as a pulmonary function test in horses

Summary Pulmonary Driving Pressure (PDP) is defined as the difference between the pulmonary artery pressure and the pulmonary capillary wedge pressure. Pulmonary driving pressure is a measure of alveolar ventilation. This parameter was determined in 20 normal horses. The mean value was 10.0 +/−2.37 mm Hg. The PaO2 in these horses varied between 98 and 110 mm Hg. In two of these 20 horses, pulmonary driving pressure was determined 10 timesconsecutively. The obtained values were within very narrow limits for the respective horses indicating the reproducibility of the technique.

The influence of clenbuterol on prostaglandin F2α-induced dyspnoea in calves

Pulmonary function tests were performed in six healthy calves. Prostaglandin F2α causes severe narrowing of both upper and lower airways (total lung resistance increased, dynamic compliance decreased). Clenbuterol administered intravenously fifteen minutes prior to prostaglandin F2α aerosol, and in increasing doses (0, 0.4, 0.8, 1.2 μg/kg), on days 1, 2, 4 and 6 of the experiment, effectively but not entirely suppressed these responses.These data indicate that β-adrenergic receptors are present in the bovine airways and that the use of clenbuterol (0.8 μg/kg) may be effective in treating clinical respiratory disease such as bronchopneumonia in calves.

The effect of clenbuterol on lung function parameters in calves suffering from bronchopneumonia

Pulmonary function testing was performed in calves affected with bronchopneumonia. In these calves respiratory rate, viscous work per litre air and per minute, intrapleural pressure difference, mean inspiratory and expiratory flow rate and ventilation per minute were significantly increased. Total resistance of the lung was just not significantly increased. Dynamic compliance and tidal volume were significantly reduced.The main effect of clenbuterol was a significant increase in dynamic compliance. The reduction in the total resistance of the lung was just not significant. These results indicate that clenbuterol can antagonise, at least partly, the alterations caused by bronchopneumonia.

Heart failure in horses: Hemodynamic monitoring and determination of LDH1 concentration

Summary In 21 Standardbred horses with complaints of poor performances, cardiac and pulmonary hemodynamics indicated heart failure. All horses had a very significant increase in mean pulmonary capillary wedge pressure indicative of left heart failure. This resulted in a very significant increase in mean pulmonary artery pressure. The driving pressure was normal. A significant increase in mean right atrial pressure was indicative for right heart failure. Total LDH levels were within normal limits but the LDH 1 fraction was very significantly increased in 9 out of the 21 horses, while in the remaining 12 only a slightly elevated LDH 1 fraction was observed.

Effect of inhaled nitric oxide on the hypoxic pulmonary vasoconstrictor response in anaesthetised calves

The effect of inhaling nitric oxide in the hypoxic pulmonary vascular response was measured in five calves anaesthetised with a combination of guaiacol, ketamine and xylazine. Alveolar hypoxia was induced by means of the inhalation of a gas mixture with an inspiratory oxygen fraction of 14-18 per cent. This alveolar hypoxia resulted in a pronounced pulmonary hypertension (mean pulmonary artery pressure in hypoxic animals: 30.2 mmHg). Inhalation of 20 and 40 ppm of nitric oxide significantly attenuated the hypoxia induced pulmonary hypertension. The effect ceased once nitric oxide administration was stopped. A concentration of 40 ppm of nitric oxide fully abolished the hypoxia induced pulmonary hypertension (mean pulmonary artery pressure during inhalation of 40 ppm nitric oxide: 22.8 mmHg). Inhalation of nitric oxide had no effect on systemic arterial blood pressure nor on systemic vascular resistance. It was concluded that inhalation of 20 or 40 ppm of nitric oxide prevented a selective pulmonary vasoconstriction during alveolar hypoxia in calves, which may be helpful in the treatment of acute respiratory disorders in calves.