THE SCINTIGRAPHIC EVALUATION OF SOLID PHASE GASTRIC EMPTYING IN NORMAL CATS

The gastric emptying half-time of solid food in normal cats was determined using a scintigraphic technique. ^99mTc-sulfur colloid was applied to dry food. Sequential images were acquired post prandial, and the gastric emptying half-time was determined for several different acquisition and processing parameters. Good correlation was found between different acquisition and processing methods, some of which made use of edge detection applications, while others used different views, or number of views from which the gastric emptying half-time was calculated. The mean ± standard deviation, (range) and median of the gastric emptying half-time determined using the geometric mean of total counts in hand-drawn regions of interest from the lateral and ventral images were 2.47 × 0.71, (1.42–3.61) and 2.37 hours respectably.     

Stable carbon isotopes accurately predict diet selection by sheep fed mixtures of C3 annual pastures and saltbush or C4 perennial grasses

The stable carbon isotope technique has been widely used to infer the dietary ecology of a range of animal species; however calibration of the technique with animals fed known diets is essential for accurate back-calculation of dietary preferences. The aim of this study was to identify suitable samples and back-calculation methods to predict short-term (2 to 3 week) dietary selection by sheep among plants with C₃ and C₄ photosynthetic pathways. Variation in integration time of dietary carbon into plasma and faeces; diet-tissue discrimination of carbon isotopes (fractionation) and the importance of accounting for the digestible or indigestible components of the diet was investigated. The results indicate that faecal and rumen samples provided the most accurate prediction of short term dietary changes in sheep selecting between C₃ and C₄ plants. The most accurate back-calculation method for these samples used δ¹³C of the C₃ and C₄ plants and accounted for both diet-tissue discrimination and differences in the indigestibility between the C₃ and C₄ forage. For faecal samples, the organic matter content of the diet originating from C₄ plants could be predicted with a mean error as low as 2.7%. Wool and plasma samples were not conducive to predicting proportion of C4 forage in the diet within 18 days after a change in diet; however plasma could be used to discriminate between animals fed 100% C₃ and C₄ diets after 3 days. The δ¹³C technique provides a valuable tool for researchers when designing pastures for dual environmental and production purposes. An understanding of what sheep select allows for development of appropriate grazing management strategies to optimise productivity and/or persistence of target species.     

AGE AND DIET EFFECTS ON RELATIVE RENAL ECHOGENICITY IN GERIATRIC BITCHES

Under controlled, but varied dietary conditions 35 geriatric, uninephrectomized, spayed Beagle bitches (dogs) observed for 4 years, renal cortical and renal medullary echogenicity was measured relative to hepatic and splenic echogenicity. Regardless of the diet fed, 60-75% of these aged dogs had renal cortical echogenicity less than that of either the liver or spleen across time; 25-35% of these dogs had renal cortical echogenicity equal to that of the liver, but less than that of the spleen across time. Less than 3% of these dogs had renal cortical echogenicity greater than that of the liver, but less than that of the spleen. Only 1 (one) of these dogs had renal cortical echogenicity equal to that of the spleen and that occurred at only one of the 14 chronologic assessments. Therefore, in either mature or aged dogs imaged with 4.0 to 5.0 MHz equipment, the renal cortical echogenicity should be considered normal if it is less than or equal to that of the liver and less than that of the spleen. In 29 dogs imaged with the 4.0/5.0 MHz equipment and 6 dogs imaged with 7.5 MHz equipment, there was no significant diet or individual dog effect. The 7.5 MHz (6 dog) group had significantly higher average cortical echogenicity scores than the 4.0/5.0 MHz (29 dog) group. However, the occurrence of renal cortical echogenicity greater than liver echogenicity was seen in only 5 of 83 samples (approximately 6.0%) made on 6 dogs imaged with 7.5 MHz equipment and only 1 of 375 samples (approximately 0.27%) made on 29 dogs with 4.0/5.0 MHz equipment. With the exception of one occurrence, all dogs had renal medullary echogenicity less than that of the liver or spleen regardless of imaging equipment frequency. The renal medulla was always hypoechoic compared to the cortex.     

Academic food-supply veterinarians: future demand and likely shortages

The future demand for and potential shortages of food-supply veterinarians have been the subject of much concern. Using the Delphi forecasting method in a three-phase Web-based survey process, a panel of experts identified the trends and issues shaping the demand for and supply of academic food-animal veterinarians, then forecasted the likely future demand and shortages of food-supply veterinarians employed in academic institutions in the United States and Canada through 2016. The results indicate that there will be increasing future demand and persistent shortages of academic food-supply veterinarians unless current trends are countered with targeted, strategic action. The Delphi panel also evaluated the effectiveness of several strategies for reversing current trends and increasing the number of food-supply veterinarians entering into academic careers. Academic food-supply veterinarians are a key link in the system that produces food-supply veterinarians for all sectors (private practice, government service, etc.); shortages in the academic sector will amplify shortages wherever food-supply veterinarians are needed. Even fairly small shortages have significant public-health, food-safety, animal-welfare, and bio-security implications. Recent events demonstrate that in an increasingly interconnected global economic food supply system, national economies and public health are at risk unless an adequate supply of appropriately trained food-supply veterinarians is available to counter a wide variety of threats ranging from animal and zoonotic diseases to bioterrorism.     

Systemic blastomycosis in a horse.

Progressive multisystemic disease caused by Blastomyces dermatitidis was diagnosed in a 17-year-old Quarter horse broodmare. The mare had been treated unsuccessfully with antibiotics for mastitis 3 months postpartum. The disease progressed to exudative cutaneous lesions affecting the ventrum, pectoral region, and limbs accompanied by weight loss across several months. Yeast bodies were observed in swabs of the cutaneous exudate, suggesting a clinical diagnosis of blastomycosis. Following referral, pleural effusion, cavitated lung lesions, and hyperproteinemia were identified, and the mare was euthanized because of poor prognosis. Necropsy revealed extensive pyogranulomas in the mammary gland, skin, subcutaneous tissues, and lungs, accompanied by thrombi in major blood vessels of the lungs and hind limbs. Histologically, pyogranulomatous inflammation was evident in many tissues, and fungal organisms were seen in sections of mammary gland, skin, subcutis, pericardium, and lung. Blastomyces dermatitidis was cultured from mammary tissue, lungs, lymph node, and an inguinal abscess. Although blastomycosis is endemic in the area of origin of the mare in northwestern Wisconsin, the disease is extremely rare in horses and hence easily misdiagnosed. Unique features of this case included the extent of mammary gland involvement and the presence of thrombi in multiple sites.     

Optimization of conditions for in vitro production of radical oxygen species and expression of tissue factor by canine mononuclear cells and granulocytes for use in high-throughput assays

The purpose of this study was to optimize conditions for high throughput measurement of radical oxygen species (ROS) production and expression of tissue factor, also termed procoagulant activity, by canine leukocytes. Granulocytes and mononuclear cells were separated by density gradient centrifugation from peripheral blood collected on several occasions from three healthy large breed dogs. To determine optimal conditions for ROS production, granulocytes were incubated for 1 or 3h in PBG (PBS containing 0.5% BSA and 5mM glucose) or RPMI containing 10% fetal bovine serum (FBS); lipopolysaccharide (LPS), zymosan, peptidoglycan (PGN) and phorbol myristate acetate (PMA) were used as stimuli. ROS was assessed by conversion of the nonfluorescent dye dihydrorhodamine 123 to fluorescent rhodamine 123 by radical species released into the media. To identify optimal conditions for expression of tissue factor, mononuclear cells were incubated for 5h in RPMI containing different concentrations of heat-inactivated FBS (HI-FBS), and LPS, zymosan, PGN or PMA as stimuli. Expression of tissue factor was determined using a one-stage recalcification assay performed in an automated nephelometric coagulation analyzer. Neither LPS nor zymosan increased ROS production by granulocytes incubated in PBG media. In contrast, granulocytes incubated in RPMI had dose-dependent increases in ROS production in response to zymosan and PGN. ROS production was significantly increased by incubation with concentrations of LPS of 0.01microg/ml or greater, and by zymosan concentrations of 0.1microg/ml or greater. ROS production in response to incubation with PMA was significantly increased starting at 10(-7)M, and was significantly greater for cells incubated in RPMI than cells incubated in PBG. LPS-, zymosan- and PGN-stimulated procoagulant activity increased in a dose-dependent manner, whereas PMA-stimulated procoagulant activity peaked at 10(-7)M. Increasing concentrations of HI-FBS significantly increased LPS-, zymosan- and PGN-induced procoagulant activity of mononuclear cells. Results obtained in this study indicate production of ROS by canine granulocytes is optimal when these cells are incubated for 3h in RPMI with LPS (0.1microg/ml), zymosan (10 microg/ml), PGN (10 microg/ml), and PMA (10(-7)M). Furthermore, canine mononuclear cells express procoagulant activity in response to LPS, zymosan, PGN, and PMA, and responses to LPS, zymosan and PGN are enhanced by the addition of HI-FBS. These findings suggest that HI-FBS retains important serum proteins that facilitate interactions between each of these bacterial or yeast derived products and the mononuclear cells. Consequently, future studies regarding the regulation of procoagulant activity by canine mononuclear cells should be performed in the presence of HI-FBS. Both assays utilized in this study allow high throughput of samples, and therefore are appropriate choices for rapid screening of conditions and/or therapeutic interventions affecting the canine inflammatory system.     

Primary Aspergillus and Fusarium keratitis in a Holstein cow

A 5-year-old female Holstein cow was examined for ocular discharge, periorbital swelling, an area of full-thickness corneal cellular infiltrate, fibrin, hypopyon, diffuse corneal edema, and miosis. The patient was diagnosed with a corneal stromal abscess and secondary anterior uveitis. Histopathology, mycotic culture, and polymerase chain reaction positive for Aspergillus and Fusarium DNA confirmed the presence of fungal infection. Response to therapy was adequate, and follow-up with the patient 1 year after diagnosis revealed a focal area of corneal fibrosis.     

Septicaemia secondary to infection by Corynebacterium macginleyi in an Indian python (Python molurus)

A seven-year-old female Indian python (Python molurus) weighing about 35kg was euthanased after several clinical episodes of stomatitis, pneumonia, ophthalmitis and dystocia over a period of four years. The animal had been maintained in a terrarium in a circus truck at an adequate temperature. During shows, however, the snake was considered to be exposed to stressful conditions for several hours at a time at low temperatures and with noise and bright lights. A post-mortem examination indicated ulcerative stomatitis, osteomyelitis, severe pneumonia and numerous granulomata and multifocal necrosis in stomach and spleen. Corynebacterium macginleyi was isolated in pure culture from the ulcerative stomatitis, and mixed with Stenotrophomonas maltophilia from the lungs and spleen. The findings indicated that the snake had died from a septicaemic process caused by C. macginleyi, probably originating from the stomatitis. The role of S. maltophilia as a secondary agent is discussed. The stress of the circus show and poor husbandry may have predisposed the animal to infection and septicaemia. This is the first report of C. macginleyi causing disease in a snake.