Cardiovascular, acid-base, electrolyte, and plasma volume changes in ponies developing alimentary laminitis.     

J R Harkema  N E Robinson  J B Scott 《American journal of veterinary research》1978,39(5):741-744

Twelve Shetland ponies were fed a high-starch ration. Seven ponies which had a transitory metabolic acidosis developed laminitis 56 hours (+/- 3.5, SEM) after overfeeding. These ponies also developed persistent hypokalemia, hyperthermia, and increased heart rate 24 hours before the onset of lameness. Serum sodium, serum chloride, hematocrit, plasma volume, and blood volume were unchanged. At the onset of clinical signs of laminitis, cardiac output and blood pressure increased, but total peripheral resistance was unchanged. None of the measured or calculated values predicted the onset of laminitis. Hypertension appeared to be a response to, rather than a cause of, lameness. Three of the remaining ponies apparently died of shock 29.3 +/- 2.7 hours after overfeeding. All 3 had severe metabolic acidosis; decreased cardiac output, systemic arterial pressure, and plasma volume; and increased hematocrit, total peripheral resistance, and pulmonary vascular resistance. The 11th pony was unaffected and the 12th pony was euthanatized.  相似文献   

Serological responses to two serovar‐independent ELISA antigens of Actinobacillus pleuropneumoniae in Australian commercial pig herds     

GJ Eamens  JR Gonsalves  A‐M Whittington  B Turner 《Australian veterinary journal》2008,86(12):465-472

Objective To compare serological responses in pig herds classified as low or high risk for disease caused by Actinobacillus pleuropneumoniae, using two ELISA tests based on serovar‐independent antigens. Procedure Cross‐sectional sampling was undertaken in 13 commercial herds, the clinical and slaughter histories of which indicated either freedom from (n = 5) or prior confirmed cases of A. pleuropneumoniae (n = 8). In nine herds, approximately 40 pigs each were sampled at 4, 8, 12, 16 and 20 weeks. Three of the remaining four herds were sampled between 6 and 30 weeks of age, and the last was sampled only prior to slaughter, at approximately 24 weeks. Sera were tested in ELISA based on two antigens common among A. pleuropneumoniae serovars: a 39‐kDa outer membrane protein and a recombinant ApxIVA‐N terminus protein. Results Sampling of 1 and 5 to 6‐month‐old pigs provided the most useful information on herd status. The 39‐kDa ELISA was sensitive in detecting infected herds, but had evidence of cross‐reactivity with high seroreactivity rates in older pigs in some low‐risk herds. The ApxIVA‐N ELISA was less seroreactive in high‐risk herds and had higher specificity in low‐risk herds. Conclusion ELISA based on the 39‐kDa subunit are of limited use, because of possible cross‐reactivity, but a high negative predictive value may be useful for risk assessment in suspect herds. Maternal antibody to ApxIVA‐N may be of value in detecting high‐risk herds, but 5% of 4‐week‐old pigs in low‐risk herds were also seropositive in this assay.  相似文献   

Failure of hyperimmune plasma to prevent pneumonia caused by Rhodococcus equi in foals     

JR HURLEY  AP BEGG† 《Australian veterinary journal》1995,72(11):418-420

SUMMARY A trial was conducted on a Thoroughbred stud to determine whether or not the administration of anti-Rhodococcus equi hyperimmune plasma would reduce the prevalence of R equi pneumonia (rattles) in foals born in the 1992 horse breeding season. Hyperimmune plasma was administered to 34 foals; another 57 foals were untreated. There was no significant difference in the number of transfused foals developing R equi pneumonia compared with the untreated foals. The time required for recovery from pneumonia between the 2 groups was not significantly different.  相似文献   

Duration of Mycoplasma hyopneumoniae Infection in Gnotobiotic Pigs   总被引：3，自引：0，他引：3       下载免费PDF全文

N.R. Underdahl  G.A. Kennedy    A.S. Ramos  JR. 《The Canadian veterinary journal. La revue veterinaire canadienne》1980,21(9):258-261

Sixteen gnotobiotic pigs raised in flexible plastic isolators (four pigs per isolator) were inoculated with a culture of Mycoplasma hyopneumoniae. One pig was killed and underwent necropsy at weekly intervals for the following 16 weeks. Macroscopic lesions were observed in the lungs of 13 of 16 pigs and microscopic lesions were found in 14 of 16 pigs. Mycoplasma hyopneumoniae was cultured from the trachea or lungs from 10 of the 16 pigs. Scanning electron microscope studies showed areas of damage to the cilia, collections, of leucocytes and mucus, and mycoplasma in the trachea as well as the bronchi. These conditions were found in all the pigs seen at necropsy from nine to 16 weeks postinoculation and there was no evidence of noticeable regression or recovery during this 16 week period.  相似文献   

Effect of feeding on plasma antibiotic concentrations in Greyhounds given ampicillin and amoxycillin by mouth     

A. D. J. Watson  JR. Egerton 《The Journal of small animal practice》1977,18(12):779-786

In a cross-over study, six Greyhounds were dosed by mouth with ampicillin and amoxycillin at 20 mg/kg, using three different feeding regimens (no food, canned food prior to dosing, and dry food ad lib ) with each drug. Antibiotic levels in plasma were determined by microbiological assay at intervals after dosing.
Plasma ampicillin concentrations tended to be lower in fed than in starved Greyhounds, but amoxycillin levels were relatively unaffected by feeding. In starved Greyhounds, ampicillin gave higher early levels than amoxycillin.  相似文献   

Eradication of actively spreading ovine footrot     

JR EGERTON 《Australian veterinary journal》1991,68(8):283-283

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Melting Temperature and Partial Melt Chemistry of H2O-Saturated Mantle Peridotite to 11 Gigapascals     

T Kawamoto  JR Holloway 《Science (New York, N.Y.)》1997,276(5310):240-243

The H2O-saturated solidus of a model mantle composition (Kilborne Hole peridotite nodule, KLB-1) was determined to be just above 1000°C from 5 to 11 gigapascals. Given reasonable H2O abundances in Earth's mantle, an H2O-rich fluid could exist only in a region defined by the wet solidus and thermal stability limits of hydrous minerals, at depths between 90 and 330 kilometers. The experimental partial melts monotonously became more mafic with increasing pressure from andesitic composition at 1 gigapascal to more mafic than the starting peridotite at 10 gigapascals. Because the chemistry of the experimental partial melts is similar to that of kimberlites, it is suggested that kimberlites may be derived by low-temperature melting of an H2O-rich mantle at depths of 150 to 300 kilometers.  相似文献   

Universality Classes of Optimal Channel Networks   总被引：1，自引：0，他引：1  

A Maritan  F Colaiori  A Flammini  M Cieplak  JR Banavar 《Science (New York, N.Y.)》1996,272(5264):984-986

Energy minimization of both homogeneous and heterogeneous river networks shows that, over a range of parameter values, there are only three distinct universality classes. The exponents for all three classes of behavior are calculated.  相似文献   

Influence of dietary arginine and glycine content on thyroid function and growth of juvenile rainbow trout, Oncorhynchus mykiss (Walbaum)     

W. W. RILEY  JR  D.A. HIGGS  B.S. DOSANJH  J.G. EALES 《Aquaculture Nutrition》1996,2(4):235-242

Juvenile rainbow trout, held at 12°C on a 12 h light :12 h dark photocycle, were fed a constant ration (1 % of body wt day ^?1) of isonitrogenous and isoenergetic diets that varied in either arginine content (3.6-56.1 g kg^?1 dry matter; experiment 1), or glycine (3.3–118 g kg^?1 dry matter) and alanine (5.0-42.3 g kg^?1 dry matter) content (experiment 2). In experiment 1, the lowest dietary level of arginine depressed growth, feed efficiency, plasma l -thyroxine (T₄) and 3,5,3′-triiodo-l -thyronine (T₃) levels and hepatic T₄ 5’monodeiodinase (5'D) activity responsible for T₄-to-T₃ conversion. Over the dietary range of 7.1–56.1 g arginine kg^?1, there was no change in 5'D activity, despite an arginine stimulation of growth. The optimum level of arginine for growth was within the range of 14.1–28.1 g kg^?1 of the diet or 32–63 g kg^?1 of dietary protein. In experiment 2, an increase in dietary glycine level, at the expense of glutamic acid, increased 5'D activity without attendant elevation of the plasma T₃ level. The latter finding suggests that glycine also induced a compensatory increase in T₃ degradation rate. This may explain why the glycine-induced increase in 5'D activity was unaccompanied by any changes in growth indices. Alteration of dietary alanine content did not affect growth or thyroid function. We conclude that of the various dietary amino acids tested, only glycine led to a progressive stimulation of hepatic T₄ 5'D activity. However, because glycine likely enhanced T₃ degradation, no increases in plasma T₃ or growth indices were found. Glycine may serve as an advance signal that activates thyroid function immediately preceding or coincident with energy and nutrient (especially protein) intake. This, in turn, may improve the efficiency of nutrient absorption and/or post-absorptive anabolic events.  相似文献   

Action of selected antibiotics on four common bacteria associated with diseases of fish     

K. E. NUSBAUM  E. B. SHOTTS  JR 《Journal of fish diseases》1981,4(5):397-404

Abstract. Four bacteria commonly associated with diseases of fish ( Aeromonas hydrophila complex, Aeromonas salmonicida, Flexibacter columnaris -like organisms and Pseudomonas fluorescens ) were evaluated in a serial dilution system for susceptibility to four antibiotics commonly used in the treatment of bacterial fish diseases (chloramphenicol, erythromycin, furpyrinol and oxytetracycline). Findings were expressed as minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Furpyrinol was found to have the lowest MIC and MBC against A. hydrophila complex, A. salmonicida and F. columnaris-like organisms. MIC and MBC's for oxytetracycline were complicated by the presenceof R-plasmids, but were less than 4.0 mcg/ml for those without plasmids. Pseudomonas fluorescens was susceptible only to oxytetracycline. MIC for all groups of organisms using chloramphenicol was generally less than 16.0 mcg/ml. Susceptibility to erythromycin by these groups of organisms was greater than 16 mcg/ml.  相似文献