Open canalicular system of platelets in porcine stress syndrome

A study was undertaken to test whether a previously reported alteration in platelet morphology could be of predictive value for the detection of stress-susceptibility in pigs. Platelets from 20 normal pigs, nine pigs classified as stress-susceptible on the basis of their response to halothane challenge, and 11 siblings of halothane reactors belonging to two different breeds were subjected to electron microscopic examination. A quantitative analysis of electron micrographs, based on the extent of dilatation of the open canalicular system in platelets and the percentage of affected platelets, revealed that halothane reactor pigs could be distinguished from normal animals on the basis of their open canalicular system score. The discrete nature of the score categories in siblings indicates that platelet alteration may be an inherent component of the porcine stress syndrome and suggests that some of the false negatives in the halothane test may be identified as stress-susceptible on this criterion. Further studies involving a larger number of halothane reactors and siblings are needed to ascertain the consistency of the open canalicular system features and eventually, to develop a simple test system based on platelet alterations for the detection of stress-susceptibility in pigs.     

Soil-solution chemistry in black locust, pine/mixed-hardwoods and oak/hickory forest stands in the southern Appalachians, U.S.A.

Soil-solution chemistry was measured over a 15-month period in three forest stands of contrasting nitrogen mineralization and nitrification rates in the southern Appalachians of North Carolina, U.S.A., using porous-cup lysimeters. In a black-locust-dominated stand, soil solution NO₃---N was 3.73 and 5.04 mg l⁻¹ at 30- and 60-cm depth respectively, and dissolved organic N ( ) was 0.718 and 0.582 mg l⁻¹ respectively. Values at 30 and 60 cm for a pine/mixed-hardwood stand were 0.032 and 0.058 mg l⁻¹ NO₃---N, and 0.201 and 0.168 mg l⁻¹ (values are means over the whole duration of the study). At both depths, soil solution conductivity, pH, Ca, Mg, K and PO₄---P were higher in black locust than in pine/mixed-hardwoods, and there were no differences in soil solution Na. In an oak/hickory stand, soil solution NO₃---N at 30-cm depth was 0.008 mg l⁻¹, and was 0.357 mg l⁻¹. At 30-cm depth, soil-solution conductivity, Ca, Mg and PO₄---P were higher in black locust than in oak-hickory, with no differences in pH, K and Na; , pH and K were higher in oak/hickory than in pine/mixed-hardwoods. In the oak/hickory and pine/mixed-hardwoods forest stands, with relatively lower soil N turnover rates, was a major portion of soil solution N.     

Diphenhydramine Intoxication in a Dog1

We report a case of diphenhydramine intoxication in a dog. A five month old intact male Labrador Retriever was presented after ingesting approximately 36 diphenhydramine tablets (50 mg/tablet; approximate ingested dose of 1800 mg or 67 mg/kg). Physical examination findings included severe ataxia, profound disorientation, severe continuous spastic muscle tremors, hyperthermia, tachycardia, tachypnea, and hyperesthesia. The dog was unresponsive to intravenous diazepam and phenobarbital, but rapidly responded to an intravenous bolus and subsequent continuous infusion of guaifenesin and supportive fluid therapy. The serum diphenhydramine level on admission was 537 ng/ml. The toxic level is not reported for dogs, but is considered>60 ng/ml in people. The dog was discharged 24 hours after admission with no apparent residual effects.     

Choosing optimal design depth for surface irrigation systems

The surface irrigation system design was formulated as a mathematical programming problem. The minimum cost of a furrow irrigation system for a hypothetical case was calculated for different design depths (25, 51, 76, 102 and 127 mm). The crop yields and net returns were simulated for the given design depths. A design (depletion) depth of 51 mm was found optimal under the given conditions.     

DETECTION OF A LIVER TUMOR IN A BEAGLE DOG USING SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY

This case report describes the detection of a liver tumor in an 11–year-old female Beagle dog using single photon-emission computed tomography (SPECT). A mass was palpated in the cranial abdomen during removal of recurrent mammary tumors. A conventional nuclear medicine liver scan, following injection of ^99mTc-sulfur colloid, was equivocal. SPECT was then performed in a second procedure, using a simple system that rotated the dog before a gamma camera. Transverse plane images clearly showed a spheric space-occupying lesion, found at gross necropsy and confirmed histologically as a hepatoma. Discrete liver tumors may be detected more readily and their size determined more accurately using SPECT than with conventional nuclear medicine approaches.     

EXPERIMENTAL ACUTE GASTRIC DILATATION AND VOLVULUS IN THE DOG: CHANGES IN BIOCHEMICAL PARAMETERS*

Acute gastric dilatation and volvulus with dilatation were produced in 11 dogs anesthetized with halothane. Blood samples were taken during these procedures for biochemical analyses. Serum potassium did not change significantly during the experimental procedure, but there was a significant increase (p<0.05) after release of the dilatation with volvulus. Renal function was impaired with significant increases (p<0.05) in the serum concentration of urea nitrogen, phosphorus, and creatinine. Evidence of cellular damage was reflected by a significant elevation (P<0.05) in glutamic-oxaloacetic transaminase activity. Serum glucose concentration increased significantly (P<0.05) during experimental gastric dilatation and dilatation with volvulus.     

Ten years of bovine virus diarrhoea virus (BVDV) control in Norway: a cost-benefit analysis

A retrospective cost-benefit analysis was carried out on the Norwegian bovine virus diarrhoea (BVD) control and eradication strategy, for the years 1993-2003. Information regarding the control cost input parameters was gathered from the cattle industry (TINE Norwegian Dairies, GENO Breeding and AI association, and GILDE Norwegian Meat), The National Animal Health Authorities and The Veterinary Institute. We accounted for variable costs (both direct costs associated with the control, and those costs carried by the farmers as a consequence of the control program). The benefit was estimated as the difference between the assumed losses without control - represented overall as 10% increase of the observed 1993 BVD virus infection level - and the observed losses during the control period. An estimate of the financial losses associated with the BVD virus (BVDV) infection was based on studies of the herd level effects on health, reproduction, and production in dairy herds with evidence of recent BVDV infection. We used a stochastic simulation model to account for the total uncertainty in both the control cost and financial loss estimates. The annual net benefits over the 10 years of BVD control were discounted to a 1993 net present value (NPV). The median NPV of the BVD control, nationally, was estimated at 130 million NOK with a distribution of the NPV ranging from +51 to +201 million NOK (5th and 95th percentiles, respectively). Out of the total control costs the farmers and the farmer-owned industries (the co-operatives) had carried about 62% of these costs; however, the farmers were also the main beneficiaries. The Norwegian experience shows a robust cost-efficiency for a BVDV eradication strategy; this stands in sharp contrast to earlier studies where the results were not supportive. Even though every cattle population and country is unique, the Norwegian findings and experiences should have wider implications.     

Evaluating predictors of apple scab with receiver operating characteristic curve analysis

ABSTRACT Apple scab (Venturia inaequalis) is a perennial threat to apple production in temperate climates throughout the world. In the eastern United States, apple scab is managed almost exclusively through the regular application of fungicides. Management of the primary phase of disease is focused on preventing infection by ascospores. Management of secondary cycles of infection is largely dependent on how well primary infections were controlled. In this study, we used receiver operating characteristic curve analysis to evaluate how well mid-season assessments of the incidence of apple scab on cluster leaves, clusters (i.e., the whorl of cluster leaves), or immature fruit can serve as predictors of apple scab on harvested fruit (harvest scab) and whether these mid-season assessments of scab could be used reliably to manage scab under various damage thresholds. Results showed that assessment of scab on immature fruit was superior at predicting harvest scab than were assessments made on clusters or cluster leaves at all damage thresholds evaluated. A management action threshold of 7% scab incidence on immature fruit was identified by Youden's index as the optimal action threshold to prevent harvest scab incidence from exceeding 5%. Action thresholds could be higher or lower than 7% when economic assumptions were factored in to the decision process. The utility of such a predictor is discussed.