LOW-FIELD MAGNETIC RESONANCE IMAGING OF BEAGLE BRAIN WITH A DEDICATED RECEIVER COIL

A specially designed radio frequency receiver coil was used in a low-field-strength (0.1 T) magnetic resonance imager to improve the image quality of the Beagle brain. The aim was to obtain better distinction of anatomic details with a better signal-to-noise ratio in shorter imaging time. The spin-echo (TR/TE = 1200/100; TR is the repetition time and TE is the echo time in ms) brain images of three Beagles indicate that the new receiver coil can fulfill these goals.     

A Case of Equine Aspergillosis: A Novel Sampling Procedure for Diagnosis

Aspergillus spp. may induce equine respiratory infections such as fungal pneumonia, guttural pouch mycosis, and systemic infection in immunocompromised individuals. This study describes a case of probable respiratory aspergillosis in a horse presenting clinical signs of the upper airway disease different from those previously reported. Nasopharyngeal swabs and guttural pouch centesis were performed, and Aspergillus flavus was isolated and identified. Following 30 days of pharmaceutical treatment with itraconazole, clinical signs resolved. Results suggested that aspergillosis should be included in the differential diagnosis of upper airway infections, guttural pouch centesis may be useful to make a correct diagnosis, and itraconazole is efficacious in the treatment of A flavus infection.     

Feeding and microbial disorders in horses: Part 3—Effects of three hay:grain ratios on microbial profile and activities

Cecal and colonic fluid contents were collected from three ponies and analyzed to determine the effects of three hay:barley ratios on their microbial and biochemical characteristics. Three diets based on chopped meadow hay and rolled barley were tested in a 3×3 Latin square experiment: 100% hay (100:0, 114gDM/KgBW^0.75/day), 70% hay-30% barley (70:30, 69gDM/KgBW^0.75/day) and 50% hay-50% barley (50:50, 58gDM/KgBW^0.75/day). Enumeration of total anaerobic and aero-anaerobic bacteria, lactate-utilizing and cellulolytic bacteria, lactobacilli and streptococci, as well as pH, lactate and VFA concentrations, were determined after 14 days adaptation to the new diet. In the large intestine, the concentrations of total bacteria were higher with the diets containing barley than with the hay diet, whereas cellulolytic bacteria were depressed with the concentrate diets. As the proportion of barley increased, concentration of lactate-utilizing bacteria, lactobacilli and streptococci increased in the colon while it did not interfere significantly on these populations in the cecum. These changes of the microflora were associated with a significant decrease in intestinal pH and [(acetate+butyrate)/propionate] ratio, and a numerical increase of lactate concentration.     

REGIONAL BRAIN PERFUSION IN 10 NORMAL DOGS MEASURED USING TECHNETIUM-99m ETHYL CYSTEINATE DIMER SPECT

Single photon emission computed tomography (SPECT) of the brain using perfusion tracers allows estimation of regional brain perfusion. This allows in vivo examination of brain function in the setting of neuropsychologic and pathophysiologic changes. However functional imaging data on brain perfusion in dogs are limited. Hence, the aim of this study was to determine the scintigraphic regional perfusion pattern of the normal canine brain. Ten healthy shepherd type dogs were injected with 925 MBq Technetium-99m ethyl cysteinate (ECD) 20 minutes before the examination. Acquisition was performed using a triple head gamma camera equipped with fanbeam collimators. Uniform attenuation correction and triple energy window correction were applied. Computed tomographic images were obtained from the same dogs, reoriented along the orbito-meatal axis and SPECT perfusion data were coregistered to the CT-volume data. Based on morphological and suggested brain divisions, regions-of-interest (ROIs) were defined for the bilateral frontocerebral, temporocerebral, parietocerebral, occipitocerebral, cerebellar, thalamic, and striatal area. Regional count density was normalized on total counts. All dogs had the highest uptake in the thalamic/striatal area compared to a rather homogeneous cerebral uptake. No significant left/right count differences were found, but a rostro-caudal gradient (+12-13%) was present. In this group, age and gender did not influence the perfusion pattern.     

DYNAMIC MAGNETIC RESONANCE IMAGING OF THE NORMAL CANINE PITUITARY GLAND

The pituitary glands of six normal dogs were evaluated using dynamic magnetic resonance imaging. T1 weighted images were obtained every 13 seconds for three minutes of three contiguous slices through the pituitary gland following a bolus intravenous injection of gadolinium-DTPA. Contrast enhancement was seen initially in the region of the pituitary stalk at 52-65 seconds followed by uniform enhancement at 104-143 seconds post injection. This pattern of enhancement was seen in all subjects and is similar to that reported in humans.     

An investigation of the concentrations of selected Fusarium mycotoxins and the degree of mold contamination of field-dried hay

The levels of selected mycotoxins and mold contamination of Ontario field-dried hay from 10 performance horse farms were examined. The farm owner, trainer or manager was questioned regarding their opinion of the quality of the hay. Half of the hay sampled showed potentially significant levels of mycotoxins, mold and actinomycete contamination. Subjective opinion did not correlate to objective analysis. Deoxynivalenol (vomitoxin), T 2 toxin and zearalenone were measured with vomitoxin present in the highest amounts. Vomitoxin is among the mycotoxins most frequently found as contaminants in cereal crops, in temperate climates, in North America. It can be concluded that the levels found in this study could potentially have an influence on the health of horses consuming such hay.