Clinical and pathologic comparison of acute leptospirosis in dogs caused by two strains of Leptospira kirschneri serovar grippotyphosa     

Greenlee JJ  Bolin CA  Alt DP  Cheville NF  Andreasen CB 《American journal of veterinary research》2004,65(8):1100-1107

OBJECTIVE: To develop a method for inducing acute leptospirosis in dogs. ANIMALS: 31 nine-week-old female Beagles. PROCEDURE: Beagles were randomly assigned to 2 inoculation groups or a control group. Dogs were inoculated on 3 successive days by conjunctival instillation of 5 x 10(7) cells of Leptospira kirschneri serovar grippotyphosa strain 82 (12 dogs) or strain RM 52 (14 dogs). Control dogs (n = 5) were similarly inoculated with sterile leptospiral culture media. Clinical signs, clinicopathologic variables, anti-leptospiral antibody titers, and evidence of leptospires in tissues and body fluids were evaluated. Dogs were euthanatized and necropsied on days 7, 14, 22, or 28 after inoculation or as required because of severe illness. RESULTS: Clinical signs in infected dogs included conjunctivitis, lethargy, diarrhea, dehydration, vomiting, and icterus. Consistent clinicopathologic alterations included azotemia, hyperphosphatemia, increased anion gap, hyperbilirubinemia, and an increase in alkaline phosphatase activity. Leptospires were cultured from the kidneys (11/12), urine (6/9), aqueous humor (9/12), blood (12/12), and liver (12/12) of dogs inoculated with strain 82. Only 3 of 14 dogs became infected after inoculation with strain RM 52. Histopathologic lesions in infected dogs included interstitial nephritis, renal tubular degeneration and necrosis, pulmonary hemorrhage, and hepatic edema and perivasculitis. CONCLUSIONS AND CLINICAL RELEVANCE: Conjunctival exposure to L kirschneri serovar grippotyphosa strain 82 resulted in acute leptospirosis in all inoculated dogs, but only 3 of 14 dogs inoculated with strain RM 52 became infected. This method of infection by serovar grippotyphosa can be used to study the pathogenesis and prevention of leptospirosis in dogs.  相似文献   

Calculation of bovine haemoglobin oxygen saturation by algorithms integrating age,haemoglobin content,blood pH,partial pressures of oxygen and carbon dioxide in the blood,and temperature     

Detry B  Cambier C  Frans A  Gustin P  Clerbaux T 《Veterinary journal (London, England : 1997)》2003,165(3):633-265

In human and veterinary medicine, arterial and venous haemoglobin oxygen saturations are often used to estimate the severity of a disease and to guide therapeutic decisions. In veterinary medicine, haemoglobin oxygen saturation (SO(2)) is usually calculated using a blood gas analyser and algorithms developed for humans. It is possible, therefore, that the values obtained in animals may be distorted, particularly in animals with a high haemoglobin oxygen affinity, like young calves. In order to verify this hypothesis, we compared the arterial (SaO(2)) and venous (SvO(2)) haemoglobin oxygen saturations calculated using three different algorithms, and the oxygen exchange fraction (OEF) at the tissue level, which is the degree of haemoglobin desaturation between arterial and venous blood (SaO(2)-SvO(2)), with the values obtained from the whole bovine oxygen equilibrium curve (OEC) determined by a reference method. The blood gas analysers underestimated SvO(2) values; consequently, the OEF was overestimated (by about 10%). Two methods of reducing these errors were assessed. As the haemoglobin oxygen affinity decreases during the first month of life in calves a relationship between PO(2) at 50% haemoglobin saturation (P50) and age was established in order to correct the calculated values of venous and arterial SO(2), taking into account the estimated position of the OEC. This method markedly reduced the error for SvO(2) and OEF. Secondly, the SO(2) was calculated using a mathematical model taking into account the age of the animal and the specific effects of pH, PCO(2), and temperature on the bovine OEC. Using this method, the mean difference between the OEF values calculated using the mathematical model and those calculated by the reference method was close to zero. The errors produced by blood gas analysers can thus be minimised in two ways: firstly, by simply introducing a P50 estimated from the age of the calf into the analyser before the measurement; and secondly, by calculating the SO(2) using a mathematical model applied to the bovine OEC.  相似文献   

Comparison of commercial enzyme-linked immunosorbent assays and agar gel immunodiffusion tests for the serodiagnosis of equine infectious anemia          下载免费PDF全文

Julie Paré  Carole Simard 《Canadian journal of veterinary research》2004,68(4):254-258

The purpose of this study was to estimate the performance characteristics (accuracy, detection limit, and precision) of commercially available enzyme-linked immunosorbent assay (ELISA) and agar gel immunodiffusion (AGID) kits in comparison with a reference AGID kit for the detection of equine infectious anemia (EIA) antibodies in horses for regulatory use in Canada. A total of 285 positive and 315 negative samples by the reference AGID were tested blindly on 2 other AGID and 4 ELISA kits. Commercially available AGID kits for the serodiagnosis of EIA were found equivalent. The 3 ELISAs directed against antibodies to the p26 core protein also performed relatively well in comparison with the reference AGID, with excellent relative accuracy and acceptable precision. The single ELISA directed against antibodies to the gp45 trans-membrane viral protein yielded a lower relative sensitivity. The performance characteristics of the ELISAs directed against antibodies to p26 are, therefore, adequate to support the implementation of ELISA for regulatory purposes in Canada.  相似文献   

Forecasting monthly catfish (Ictalurus punctatus.) pond bank and feed prices     

Mohammad R. Hasan  Carole R. Engle 《Aquaculture Economics & Management (Blackwell Science)》2019,23(1):86-110

Volatility in catfish pond bank and feed prices lead to profit uncertainty in the catfish industry. Analysis of the factors that affect those prices and development of a forecasting model would provide guidance to catfish farm managers. Error-correction models (ECM) based on cointegrating relationships among variables were specified following development of a single-equation ARIMAX model. Factors identified as those that influence catfish price were: lagged value of catfish, feed and substitute product prices, while those that influenced feed price were: lagged value of feed, corn and soybean prices. ECM estimates implied that fish price adjusts approximately 6% and feed price 22% to the long-run equilibrium in 1?month. The analysis showed that it takes less than 17?months and 5?months to correct for long-run disequilibrium for catfish and feed prices, respectively. The ARIMAX model demonstrated a better fit for both in-sample and out-of-sample forecasting for catfish price and had better out-of-sample predictive ability for feed prices.  相似文献   

The Effect of On-Farm Production of Various Sizes of Stocker Caffish Ictalurus punctatus on Farm Profitability.     

Steeve  Pomerleau Carole R.  Engle 《Journal of the World Aquaculture Society》2005,36(3):291-301

Abstract— The effect of on‐farm production of various sizes of stocker catfish Ictalurus punctatus on farm profitability was compared to profitability of understocking fingerlings directly into multiple‐batch growout production. Vat‐graded catfish averaging 9 × 2 g (10 cm total length) and 27× 8 g (15 cm total length) were stocked into eight 0.1‐ha ponds at 100,000 fingerlingdha. Fish were fed once daily to apparent satiation and harvested 210 d after stocking. There were no significant differences (P < 0.10) in yield, feed conversion ratio (FCR), and survival across treatments. Mean gross yield (× SD) was 9,469 × 852 kg/ha and 8,846 × 2,099 kg/ha; net yield averaged 8,531× 885 and 6,374 × 2,189 kg/ha; FCR averaged 1.8 × 0.1 and 2.4 × 0.7, and survival averaged 38 × 7% and 26 ×11% for the 10‐cm and 15‐m fingerling stocking treatments, respectively. While experimental survival was low, varying survival rates of stockers in the economic analysis did not affect selection of the most profitable stocking strategies. The 15‐cm hgerlings reached a size significantly larger (361× 81 g or 32.8 × 2.2 cm) than the 10‐cm fingerlings (255 × 28 g or 29.6 × 1.4 cm) (P < 0.07). Whole‐farm budgets were developed based on three sizes of farm (65, 130, and 260 ha) and eight production strategies involving the purchase of different sizes of fingerlings for either understocking growout ponds (6,12, or 37‐g fingerlings) or to grow into stockers (114,135, 176, 255, or 361 9). Purchasing 37‐g advanced fingerlings for multiple‐batch production was the most profitable strategy for the three sizes of farm. The second most important profit‐maximizing strategy for larger farm sizes was single‐batch production with 255‐g stockers produced on‐farm, but purchasing 12‐g fingerlings to stock into multiple‐batch production was the second most profitable strategy for the smallest farm. Sensitivity analysis indicated that the results were robust to variation in survival, prices, and other production characteristics. Risk analysis indicated that purchasing 37‐g advanced fingerlings for multiple‐batch production was associated with the lowest levels of economic risk for growout production.  相似文献   

RADIOGRAPHY REVIEW: THE VASCULAR AND BRONCHIAL PATTERNS OF PULMONARY DISEASE     

Carole W.  Myer  DVM  MS 《Veterinary radiology & ultrasound》1980,21(4):156-160

Pulmonary blood vessels account for the majority of radiographically visible structures in normal lung. The vascular pattern of pulmonary disease is characterized by changes in vessel size, shape, contour. Changes in size can be classified as hypo vasularity (decreased size) or hyper vascularity (increased size). The pulmonary arteries and veins may be affected separately or simultaneously. In normal lung, the bronchial structures peripheral to the hilar area are not seen clearly. The bronchial pattern of pulmonary disease is characterized by alteractions in bronchial wall thickness and dinsity, or in bronchial lumen diameter. Mixtures of the four lung patterns, i.e. , alveolar, interstitial, bronchial, and vascular, occur frequently. The lung radiographic pattern in an individual animal depends not only on the disease process present, but also on the stage of the disease during which they are radiographed.  相似文献   

Sustainable Growth of Aquaculture: The Need for Research to Evaluate the Impacts of Regulatory Frameworks          下载免费PDF全文

Carole R. Engle 《Journal of the World Aquaculture Society》2016,47(4):461-463

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Factors Driving Aquaculture Technology Adoption          下载免费PDF全文

Ganesh Kumar  Carole Engle  Craig Tucker 《Journal of the World Aquaculture Society》2018,49(3):447-476

Technology adoption has played a key role in the global development and increase in agricultural productivity. However, the decision to adopt a new technology on farms is complex. While the factors that drive the adoption of new technologies have been well studied in agriculture, less attention has been paid to drivers of technology adoption in aquaculture. Aquacultural technologies have developed and advanced rapidly in recent decades, but not all technologies have been adopted readily by farmers. This review paper summarizes some of the critical factors that influence aquaculture technology adoption decisions such as: (1) method of information transfer, (2) characteristics of the technology, (3) farm characteristics, (4) economic factors, and (5) sociodemographic and institutional factors. Fish farmers have tended to adopt technologies that are perceived to be more advantageous than others in terms of productivity, cost efficiency, and ease of management. Price of aquaculture products and profit expectations from business ventures were key economic factors influencing adoption decisions. Given the wide array of species, production practices, and global nature of aquaculture, the intensity and the extent of adoption of technologies depend on the nature of the industry in which they are adopted and their economic, social, political, and regulatory environments.  相似文献   

Influence of Simulated Double‐crested Cormorant,Phalacrocorax auritus,Predation on Multiple‐batch Production of Channel Catfish,Ictalurus punctatus          下载免费PDF全文

Brian S. Dorr  Carole R. Engle 《Journal of the World Aquaculture Society》2015,46(3):319-327

The double‐crested cormorant, Phalacrocorax auritus, is considered the primary depredating bird species on commercially produced channel catfish, Ictalurus punctatus, in the southeastern USA. We simulated different levels of cormorant predation on losses at harvest and economic effects on channel catfish production in a multiple‐batch cropping system. We observed significant (P < 0.05) declines in catfish production at increasing levels of cormorant predation in this study. This decline was mitigated by increased individual growth of catfish at higher predation rates (i.e., lower catfish densities). This mitigating effect produced a non‐linear relationship with total kg of catfish harvested per pond resulting in a non‐linear incremental increase in breakeven price related to predation. Costs of production ($/kg) increased with increasing predation levels up to very high levels of predation with a cumulative maximum increase in breakeven price of $0.143/kg. These results indicate that losses at harvest due to cormorant predation occur immediately but are mitigated in part by compensatory growth of individual catfish. Losses due to cormorant predation in multi‐batch systems can be considerable, but there is not a 1:1 relationship between losses and kg of catfish harvested due to compensatory factors.  相似文献   

Quantitative transmission characteristics of different H5 low pathogenic avian influenza viruses in Muscovy ducks     

Éric Niqueux  Jean-Paul Picault  Michel Amelot  Chantal Allée  Josiane Lamandé  Carole Guillemoto  Isabelle Pierre  Pascale Massin  Guillaume Blot  François-Xavier Briand  Nicolas Rose  Véronique Jestin 《Veterinary microbiology》2014

EU annual serosurveillance programs show that domestic duck flocks have the highest seroprevalence of H5 antibodies, demonstrating the circulation of notifiable avian influenza virus (AIV) according to OIE, likely low pathogenic (LP). Therefore, transmission characteristics of LPAIV within these flocks can help to understand virus circulation and possible risk of propagation. This study aimed at estimating transmission parameters of four H5 LPAIV (three field strains from French poultry and decoy ducks, and one clonal reverse-genetics strain derived from one of the former), using a SIR model to analyze data from experimental infections in SPF Muscovy ducks. The design was set up to accommodate rearing on wood shavings with a low density of 1.6 ducks/m²: 10 inoculated ducks were housed together with 15 contact-exposed ducks. Infection was monitored by RNA detection on oropharyngeal and cloacal swabs using real-time RT-PCR with a cutoff corresponding to 2–7 EID50. Depending on the strain, the basic reproduction number (R₀) varied from 5.5 to 42.7, confirming LPAIV could easily be transmitted to susceptible Muscovy ducks. The lowest R₀ estimate was obtained for a H5N3 field strain, due to lower values of transmission rate and duration of infectious period, whereas reverse-genetics derived H5N1 strain had the highest R₀. Frequency and intensity of clinical signs were also variable between strains, but apparently not associated with longer infectious periods. Further comparisons of quantitative transmission parameters may help to identify relevant viral genetic markers for early detection of potentially more virulent strains during surveillance of LPAIV.  相似文献