The effect of three different doses of sodium pentosan polysulphate on haematological and haemostatic variables in adult horses

OBJECTIVE: To evaluate the effects of three different doses of sodium pentosan polysulphate (PPS) on haematological and haemostatic variables in adult horses. DESIGN: Eight adult standardbred horses were used. All horses received a single injection of 0, 3, 6, and 10 mg/kg of PPS at the beginning of each treatment week for 4 weeks so that by the end of the study all horses had received all four doses of PPS. Blood samples were collected at 0, 1, 2, 3, 4, 6, 8, 12, 24, 48, and 168 h after each weekly injection of PPS. Variables measured were packed cell volume, haemoglobin, red blood cell count, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, platelet count, white cell count, neutrophil count, lymphocyte count, eosinophil count, monocyte count, serum protein, fibrinogen, prothrombin time, and activated partial thromboplastin time (PTT). Data were analysed using an ANOVA. Significance was set at P < 0.05. RESULTS: There was a dose-dependent increase in PTT. A significant increase in PTT occurrred in all treatment groups when compared to horses receiving 0 mg/kg in which there was no change over time. The PTT values all returned to baseline by 48 h after treatment. The mean neutrophil count was higher 3 h after treatment when compared to time 0. Horses receiving 3 mg/kg of PPS had a higher lymphocyte count 4 h after injection, and those receiving 6 and 10 mg/kg had higher counts at 3,4,6 and 8 h after injection when compared to time 0. At 8 h after injection horses receiving 6 and 10 mg PPS had higher lymphocyte counts than horses not receiving PPS. CONCLUSIONS: PPS causes a dose-dependent prolongation of PTT in horses. At the dose rates currently recommended for treatment of joint problems in horses this increase was small and remained elevated from baseline for up to 24 h. Based on these findings doses of PPS up to 3 mg/kg should not be administered to horses within 24 h of high stress activities or where physical injury may occur.     

ENDOSCOPIC ULTRASONOGRAPHY FOR THE DIAGNOSIS OF INTRATHORACIC LESIONS IN TWO DOGS

Endoscopic ultrasound was developed initially in humans to overcome limitations of conventional ultrasound in examining certain internal organs due to intervening bone or air-filled structures. Endoscopic ultrasound has been used most widely in investigation of the gastrointestinal tract in humans, but many intrathoracic applications as well as endoscopic ultrasound-guided techniques have recently been described. Mediastinal and pulmonary structures can be examined with endoscopic ultrasound since a high frequency ultrasound probe can be brought into close contact with the areas of interest via a transesophageal approach. The purpose of this report is to describe the application of endoscopic ultrasound as an aid in the diagnosis of intrathoracic disease in the dog. Two dogs, one with a history of prior esophageal foreign body extraction, the other with apathy, weakness and dyspnea were referred for further investigation. Both dogs had caudal intrathoracic soft tissue opacities diagnosed radiographically, but their origin and nature were difficult to determine. Conventional ultrasound was limiting in both dogs due to their location and superimposition of gas-filled structures. With endosonography lesions were characterized more completely. We have found endoscopic ultrasound to be an elegant diagnostic tool for the investigation of radiographically detected intrathoracic lesions in the dog whose origins are difficult to determine or do not lend themselves to investigation by conventional ultrasound. Endoscopic ultrasound provides valuable diagnostic information complementary to that provided radiographically which aids in therapeutic planning. Endoscopic ultrasound was also more sensitive for detecting mediastinal lymphadenomegaly than radiography in one of the dogs. An additional advantage of endoscopic ultrasound is the fact that US-guided tissue sampling can be performed during the examination.     

REVIEW OF DIAGNOSTIC IMAGING OF EAR DISEASES IN THE DOG AND CAT

Diagnostic imaging techniques (conventional radiography, computed tomography and magnetic resonance imaging) are an essential tool in the diagnostic work-up of ear diseases. Conventional radiography is commonly used, but often lacks sensitivity. Computed tomography (CT) and magnetic resonance (MR) are complementary imaging studies of the middle ear, labyrinth, internal auditory canal and their contents. CT provides excellent images of bony structures and is indicated where osseous changes are of greatest diagnostic importance. MR is superior in imaging soft tissue components including intralabyrinthine fluid. Therefore, more than one of these imaging techniques may be required in order to make a diagnosis.     

Dynamics of Oxidation of a Fe2+-Bearing Aluminosilicate (Basaltic) Melt

Rutherford backscattering spectroscopy (RBS) and microscopy demonstrate that the approximately 1400°C oxidation of levitated droplets of a natural Fe2+-bearing aluminosilicate (basalt) melt occurs by chemical diffusion of Fe2+ and Ca2+ to the free surface of the droplet; internal oxidation of the melt results from the required counterflux of electron holes. Diffusion of an oxygen species is not required. Oxidation causes the droplets to go subsolidus; magnetite (Fe3O4) forms at the oxidation-solidification front with a morphology suggestive of a Liesegang-band nucleation process.