Studies on the pathogenesis of staphylococcal osteomyelitis in chickens. II. Role of the respiratory tract as a route of infection

Groups of 6-week-old broiler chickens were exposed to Staphylococcus aureus by aerosol, intratracheal or intravenous (control) inoculation. No lesions were produced by aerosol. A single dose of up to 5 X 10(10) organisms given intratracheally failed to produce any lesions. Single or repeated doses of 5 X 10(11) organisms given intratracheally resulted in osteomyelitis in a low proportion of chickens.     

Etiopathogenesis, clinical manifestations, and management of canine silica urolithiasis

Silica uroliths were first recognized in dogs in the mid 1970s. Currently available data suggest that dietary factors may play a role in their pathogenesis. Diagnosis is facilitated by their typical jackstone appearance but must be verified by quantitative analysis. Surgery is the only feasible method of treatment.     

In vitro evaluation of canine and feline calcium oxalate urolith fragility via shock wave lithotripsy

OBJECTIVE: To test the hypothesis that feline calcium oxalate uroliths are intrinsically more resistant to comminution via shock wave lithotripsy (SWL) than canine calcium oxalate uroliths through comparison of the fragility of canine and feline uroliths in a quantitative in vitro test system. SAMPLE POPULATION: Calcium oxalate uroliths (previously obtained from dogs and cats) were matched by size and mineral composition to create 7 pairs of uroliths (1 canine and 1 feline urolith/pair). PROCEDURE: Uroliths were treated in vitro with 100 shock waves (20 kV; 1 Hz) by use of an electrohydraulic lithotripter. Urolith fragmentation was quantitatively assessed via determination of the percentage increase in projected area (calculated from the digital image area of each urolith before and after SWL). RESULTS: After SWL, canine uroliths (n = 7) fragmented to produce a mean +/- SD increase in image area of 238 +/- 104%, whereas feline uroliths (7) underwent significantly less fragmentation (mean image area increase of 78 +/- 97%). The post-SWL increase in fragment image area in 4 of 7 feline uroliths was < 50%, whereas it was > 150% in 6 of 7 canine uroliths. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that feline calcium oxalate uroliths are less susceptible to fragmentation via SWL than canine calcium oxalate uroliths. In some cats, SWL may not be efficacious for fragmentation of calcium oxalate nephroliths or ureteroliths because the high numbers of shock waves required to adequately fragment the uroliths may cause renal injury.     

Comparison of peripheral and core temperatures in anaesthetized hypovolaemic sheep

OBJECTIVE: To compare rectal (C(R) degrees ), coronary band (P(CB) degrees ) and ear base (P(E) degrees ) temperatures with pulmonary arterial temperature (C(PA) degrees ), and to investigate the relationship between core-peripheral temperature difference ([C - P]t degrees ) and cardiac output (Qt) in an acute ovine trauma model (PIL 60/9064). STUDY DESIGN: Observational study. ANIMALS: Thirteen mixed-breed male sheep, body mass (mean +/- SD) 45.50 +/- 4.21 kg, aged approximately 1 year. MATERIALS AND METHODS: Anaesthesia was induced with intravenous etomidate 0.5 mg kg(-1) and midazolam 0.5 mg kg(-1) and following endotracheal intubation maintained with halothane in a 2:1 N(2)O:O(2) mixture. The lungs were mechanically ventilated to maintain normocapnia. Core temperature was measured using a pulmonary arterial thermistor. Rectal temperature and peripheral temperatures at the thoracic limb coronary band and ear base were recorded using thermistor probes with a multi-channel recorder. Cardiac output was measured by continuous thermodilution. Recordings were taken hourly over a 24-hour period. After baseline data collection, hypovolaemia was induced by haemorrhage from bilateral femoral fractures. The development of hypovolaemic shock was confirmed by falling Qt, central venous pressure, mean arterial pressure and urine output. Resuscitation was attempted using intravenous fluids, inotropes and vasoconstrictors. Nine sheep received lumbosacral extradural bupivacaine. RESULTS: The rectal temperature correlated closely with pulmonary arterial temperature in all sheep (r(c) = 0.924). There was no consistent statistically significant relationship between Qt and [C - P]t degrees . CONCLUSIONS AND CLINICAL RELEVANCE: Rectal temperature accurately reflected core temperature in anaesthetized sheep but [C - P]t degrees was unrelated to Qt, under the conditions described in this study.