Short- and long-term influence of perinatal dexamethasone treatment on swine growth

The objective was to evaluate the effects of perinatal dexamethasone (Dex) treatment on postnatal growth in pigs. Experiment 1: 42 piglets were assigned according to birth weight and sex to receive either Dex (1 mg/kg body weight) or sterile saline (Control; equivalent volume) i.m. within 1h of birth. Body weights were recorded weekly and at sacrifice (day 18). Birth weights (1.43 +/- 0.05 kg) did not differ between treatment groups (P > 0.19). At day 18, Dex pigs were heavier than Control pigs (5.46 +/- 0.24 and 4.45 +/- 0.26 kg, respectively). Serum IGF-1 was 17.3% higher in Dex pigs (P < 0.04) compared to Controls. For serum GH, there was a treatment x sex interaction (P < 0.04) with GH being 51% lower in Dex males compared to Control males, and no differences in females. Experiment 2: 71 pigs were assigned according to birth weight and sex to receive either Dex (2 mg/kg body weight) or sterile saline (Control; equivalent volume) i.m. within 1 h of birth. Body weights were recorded weekly until weaning (day 21) and then every 14th day until market weight. Birth weights (1.53 +/- 0.03 kg) did not differ (P > 0.35) between treatment groups or sexes. Dexamethasone increased growth from birth to market weight by 4.15%. Carcass weights were not different (P > 0.34) between Dex (89.9 +/- 1.17 kg) and Control pigs (88.6 +/- 1.36 kg). Overall, Dex enhanced growth in pigs from birth to market weight with minimal effects on carcass and meat quality.     

Tremorgenic mycotoxin intoxication with penitrem A and roquefortine in two dogs

In this report, we describe the natural intoxication of 2 dogs that consumed moldy dairy products found in the household garbage and the procedures used to identify and quantify the tremorgenic mycotoxins, roquefortine and penitrem A, in the remaining portions of ingested materials. Following the ingestion of mycotoxins, the dogs of our report developed muscle tremors or seizures that resembled clinical signs of strychnine poisoning. Roquefortine was the predominant mycotoxin in a moldy cream cheese wrapper that was found among scattered garbage consumed by the first dog. Penitrem A was the only mycotoxin detected in discarded moldy macaroni and cheese that was consumed by the second dog. Treatment of dogs with tremorgenic mycotoxin intoxication involves supportive care. Close monitoring is important because the development of aspiration pneumonia is common and has been reported as the cause of death. Clinical signs of intoxication gradually resolve within 24 to 48 hours.     

INFLUENCE OF NORMOVOLEMIC ANEMIA ON DOPPLER-DERIVED BLOOD VELOCITY RATIOS OF ABDOMINAL SPLANCHNIC VESSELS IN CLINICALLY NORMAL DOGS

Doppler spectra of the abdominal aorta (AAo), cranial mesenteric artery (CMA), celiac artery (CA), and left renal artery (LRA) were obtained from 11 fasted, clinically healthy, conscious Beagles before and after inducing severe acute normovolemic anemia (mean±standard deviation hematocrit 16.0±0.77%). Peak systolic, end diastolic, and time-averaged mean velocities were measured. The different vessels were compared with each other. Peak systolic velocity ratio and time-averaged mean velocity ratio of splanchnic vessels to corresponding variables of the AAo were computed and compared between and within vessels during physiologic and anemic states. There was no difference between LRA and AAo, CMA or CA regarding time-averaged mean velocity, time-averaged mean velocity ratio, or end diastolic velocity during the physiological state. During the anemic state, LRA mean time-averaged mean velocity ( P ≤0.008) and mean end diastolic velocity ( P ≤0.041) were significantly lower than those of AAo, CMA, and CA. Mean time-averaged mean velocity ratio of the LRA was also significantly ( P ≤0.004) lower than the CMA and CA ratios, and significantly ( P =0.014) lower during anemic state than physiologic state of the same vessel. End diastolic and time-averaged mean velocities of the AAo, CMA, and CA increased proportionally during anemia, but there was a relatively less increase in the same variables of the LRA, suggesting less increase in blood flow. Doppler ratios allowed a noninvasive comparison between splanchnic and aortic hemodynamics. Velocity ratios might be useful for clinical detection of relative hemodynamic changes between different vessels.     

QUANTIFICATION OF LEFT VENTRICULAR MASS USING CARDIAC MAGNETIC RESONANCE IMAGING COMPARED WITH ECHOCARDIOGRAPHY IN DOMESTIC CATS

The hypotheses were that cardiac magnetic resonance imaging (cMRI) would accurately determine LV mass in domestic cats and would do so more accurately than echocardiography (ECHO). ECHO was performed on seven sedated cats. LV mass was calculated using the truncated ellipse formula from a right parasternal long-axis view. T1 weighted gradient echo cMRI was acquired from anesthetized cats during multiple phases of the cardiac cycle. Short-axis images were obtained by acquiring 3 mm thick contiguous slices perpendicular to the cardiac long axis. LV mass was determined using Simpson's rule. Endocardial and epicardial borders were traced on each slice at end-systole, end-diastole, and mid-cycle and the difference in areas was myocardial area. Myocardial area was multiplied by slice thickness to calculate myocardial volume. Total (summated) myocardial volume was multiplied by myocardial density (1.05) to obtain LV mass at three measured phases of the cardiac cycle. Cats were euthanized and the LV was dissected and weighed to determine true mass. CMRI at end-systole most accurately quantified LV mass and was more accurate than echocardiography (P = 0.0078). Actual LV mass ranged from 6.5 to 10.5 g (mean = 8.5 g, SD = 1.6 g) compared with MRI LV mass at end-systole, which ranged from 6.7 to 11.1 g (mean = 8.7 g, SD = 1.7 g) and echocardiographic LV mass at enddiastole, which ranged from 5.2 to 9.1 g (mean= 7.1 g, SD = 1.8 g). Inter- and intraobserver variability for cMRI was 2%. CMRI obtained at end-systole accurately and reliably quantifies LV mass in domestic cats. It is more accurate than the echocardiographic method used in this study.     

Detection and determinants of Escherichia coil O157:H7 in Alberta feedlot pens immediately prior to slaughter.

Food safety risks due to Escherichia coli O157:H7 may be affected by variability in prevalence in or on live cattle at slaughter. Our objectives were to assess the prevalence and risk factors associated with E. coli O157:H7 in feedlot pens immediately prior to slaughter, and assess relationships among methods of monitoring the E. coli O157:H7 status of pre-harvest pens. We studied 84 pens containing a total of nearly 27,000 head of cattle in commercial feedlots in Alberta during 2003 and 2004. Sampling devices (ROPES) prepared from manila ropes were used to detect high prevalence pens. Forty of 84 pens (48%) were classified ROPES-positive. Within pens, fecal prevalence ranged between 0% to 80% (median = 20%) and the hide prevalence ranged between 0% and 30% (median = 0%). Pens that were ROPES-positive had a higher median prevalence for feces (40%) and for hides (3.8%) than those that were ROPES-negative (13.3% and 0%, respectively). The prevalence of E. coli O157:H7 in pens immediately prior to slaughter was found to be quite high or very low even within feedlots and seasons. Factors such as sampling month, temperature, precipitation, pen floor conditions, and water tank cleanliness were associated with E. coli O157:H7 outcome measures, although associated factors were not completely consistent among years and outcome measures. Fecal and hide prevalence are considered primary pre-harvest indicators of potential carcass contamination, but other methods such as ROPES that are associated with these outcomes may provide logistic advantages to efficiently classify pens of cattle as high or low risk to food safety.     

Clinical chemistry values and tissue enzyme activities in western barred bandicoots (Perameles bougainville)

BACKGROUND: The western barred bandicoot, Perameles bougainville, is an endangered Australian marsupial species whose survival is threatened by a papillomatosis and carcinomatosis syndrome. Investigations to characterize this syndrome would benefit from species-specific clinical chemistry data. OBJECTIVES: The purpose of this study was to determine plasma biochemical reference values and to determine enzyme activities in various tissues of P. bougainville. METHODS: Heparinized blood samples were collected by jugular venipuncture from 53 clinically healthy bandicoots of both sexes and at 3 geographic locations. Plasma was analyzed for routine clinical chemistry variables using an automated biochemistry analyzer. Tissues obtained following humane euthanasia of 3 bandicoots were analyzed for alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), creatine kinase (CK), alpha-amylase (AML), and gamma-glutamyltransferase (GGT) activities. RESULTS: Significant differences in the results were found for animals based on geographic location and sex; hence, results were expressed as minimum and maximum values. A population reference interval was calculated for AST activity (20-283 U/L). ALT was found mainly in the liver, with lower levels in cardiac and skeletal muscle and kidneys. AST was detectable in many tissues, including the heart, liver, kidneys, and central nervous system; CK was found in skeletal and cardiac muscle and central nervous system; AML was found in the pancreas; and GGT was found mainly in kidneys with lower levels in the intestines and pancreas. CONCLUSIONS: These findings will facilitate the interpretation of clinical chemistry results from P. bougainville and thereby inform population management and clinical decision-making.     

Cartilage-derived retinoic acid-sensitive protein in equine synovial fluid from healthy and diseased joints

Reasons for performing study: More sensitive and specific diagnostic methods for early detection of changes in the joint cartilage are needed. Cartilage‐derived retinoic acid‐sensitive protein (CD‐RAP) is a potential marker of cartilage synthesis and regeneration. This is the first study on equine CD‐RAP. Objectives: To evaluate the ability of a commercially available human sandwich ELISA assay to detect equine CD‐RAP in synovial fluid from healthy and diseased joints. Methods: Synovial fluid was collected from 28 horses with no signs of joint disease and from 5 with induced inflammatory arthritis. CD‐RAP concentrations were measured using a human CD‐RAP ELISA. Intra‐ and interassay imprecision of the assay were evaluated by multiple measurements on pools of equine synovial fluid. Assay inaccuracy was determined by linearity under dilution. Results: The assay showed moderate to large intra‐ and interassay variation when applied to equine synovial fluid. Equine CD‐RAP was detected in synovial fluid from healthy horses ranged at 8.2–52 ng/ml. Repeated arthrocentesis (after injection of isotonic saline), age, joint or gender did not significantly affect CD‐RAP concentrations. Twelve hours after intra‐articular injection of lipopolysaccharide, concentrations of CD‐RAP were significantly lower than after injection of isotonic saline and remained significantly lower until the end of the study at 144 h. Conclusion and potential relevance: The assay is suitable for longitudinal monitoring of CD‐RAP concentration in individual horses. Disease significantly influenced CD‐RAP levels. Similar to previous results obtained in man, CD‐RAP seems to be a marker of cartilage synthesis and/or regeneration in horses.