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91.
OBJECTIVE: To compare the anesthetic index of sevoflurane with that of isoflurane in unpremedicated dogs. DESIGN: Randomized complete-block crossover design. ANIMALS: 8 healthy adult dogs. PROCEDURE: Anesthesia was induced by administering sevoflurane or isoflurane through a face mask. Time to intubation was recorded. After induction of anesthesia, minimal alveolar concentration (MAC) was determined with a tail clamp method while dogs were mechanically ventilated. Apneic concentration was determined while dogs were breathing spontaneously by increasing the anesthetic concentration until dogs became apneic. Anesthetic index was calculated as apneic concentration divided by MAC. RESULTS: Anesthetic index of sevoflurane (mean +/- SEM, 3.45 +/- 0.22) was significantly higher than that of isoflurane (2.61 +/- 0.14). No clinically important differences in heart rate; systolic, mean, and diastolic blood pressures; oxygen saturation; and respiratory rate were detected when dogs were anesthetized with sevoflurane versus isoflurane. There was a significant linear trend toward lower values for end-tidal partial pressure of carbon dioxide during anesthesia with sevoflurane, compared with isoflurane, at increasing equipotent anesthetic doses. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that sevoflurane has a higher anesthetic index in dogs than isoflurane. Sevoflurane and isoflurane caused similar dose-related cardiovascular depression, but although both agents caused dose-related respiratory depression, sevoflurane caused less respiratory depression at higher equipotent anesthetic doses.  相似文献   
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Exercise-induced gastritis and gastric ulcers are common in humans and horses, and recently have been described in racing sled dogs. The cause of exercise-induced gastric disease is not completely understood in any species, but pharmacologic suppression of acid secretion is an effective treatment in humans and horses. Thus, we tested the hypothesis that omeprazole, a proton-pump inhibitor shown to reduce gastric acid secretion in dogs, would reduce the severity of exercise-induced gastric disease. Three teams of 16 dogs each competing in the 2002 Iditarod Sled Dog Race were recruited for participation. Within each team, dogs were randomly assigned to either treatment (20 mg omeprazole PO q24h) or placebo. Treatments were administered until either completion of the race or withdrawal of an individual dog from competition. Gastric endoscopy was performed in all dogs 24 hours after completion or withdrawal, and the gastric mucosa was scored by using a subjective severity score (0 = normal, 3 = numerous bleeding ulcers). Treatment with omeprazole significantly reduced mean gastricseverity score compared to placebo (omeprazole: 0.65 +/- 0.17, placebo: 1.09 +/- 0.18; P = .028), but also was associated with increased frequency of diarrhea during the race (omeprazole 54%, placebo 21%; P = .017). Examination of our data suggests that omeprazole may be an effective treatment for exercise-induced gastric disease in racing sled dogs. However, further investigation regarding the cause and clinical relevance of diarrhea associated with omeprazole treatment must be conducted before omeprazole can be recommended for routine prophylactic treatment in these athletes.  相似文献   
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Diversity and weed community composition of mid-season plant stands and autumn seedbanks were examined in spring barley–red clover cropping systems that varied according to crop rotation, tillage and weed management. Weed plant and seed density data collected over 4 years were used in the calculation of species richness (number of species), evenness (Shannon's E) and diversity (Shannon's H′), and in multivariate analysis (canonical discriminant analysis) of weed communities. Weed diversity indices were low (H′ < 2.0) but sensitive to management practices. Evenness had intermediate values (E = 0.4–0.8), suggesting little evidence of truly dominant species, particularly in the seedbanks. The difference in the number of species between treatments was never large (approximately two to four species). Overall, diversity indices were highest in the low disturbance treatments, particularly those with minimum weed management. Factors affecting ordination were somewhat different from those affecting diversity. Tillage had little effect on weed diversity indices but had a more major role in determining weed community composition. Seedbanks in no-till and monoculture-chisel plough treatments appeared to have more distinctive species composition compared with other treatments. Weed species assembly in seedbanks showed little discrimination across treatments and over time, confirming the ability of seedbanks to buffer disturbances across a variety of cropping systems. The use of diversity indices revealed part of the complexity of weed communities associated with disturbance in cropping systems, whereas ordination singled out species–cropping systems associations, which may be more meaningful to weed management.  相似文献   
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OBJECTIVE: To determine sedative and cardiorespiratory effects of i.m. administration of medetomidine alone and in combination with butorphanol or ketamine in dogs. DESIGN: Randomized, crossover study. ANIMALS: 6 healthy adult dogs. PROCEDURES: Dogs were given medetomidine alone (30 micrograms/kg [13.6 micrograms/lb] of body weight, i.m.), a combination of medetomidine (30 micrograms/kg, i.m.) and butorphanol (0.2 mg/kg [0.09 mg/lb], i.m.), or a combination of medetomidine (30 micrograms/kg, i.m.) and ketamine (3 mg/kg [1.36 mg/lb], i.m.). Treatments were administered in random order with a minimum of 1 week between treatments. Glycopyrrolate was given at the same time. Atipamezole (150 micrograms/kg [68 micrograms/lb], i.m.) was given 40 minutes after administration of medetomidine. RESULTS: All but 1 dog (given medetomidine alone) assumed lateral recumbency within 6 minutes after drug administration. Endotracheal intubation was significantly more difficult when dogs were given medetomidine alone than when given medetomidine and butorphanol. At all evaluation times, percentages of dogs with positive responses to tail clamping or to needle pricks in the cervical region, shoulder region, abdominal region, or hindquarters were not significantly different among drug treatments. The Paco2 was significantly higher and the arterial pH and Pao2 were significantly lower when dogs were given medetomidine and butorphanol or medetomidine and ketamine than when they were given medetomidine alone. Recovery quality following atipamezole administration was unsatisfactory in 1 dog when given medetomidine and ketamine. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that a combination of medetomidine with butorphanol or ketamine resulted in more reliable and uniform sedation in dogs than did medetomidine alone.  相似文献   
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OBJECTIVE: To evaluate the effects of butorphanol and carprofen, alone and in combination, on the minimal alveolar concentration (MAC) of isoflurane in dogs. DESIGN: Randomized complete-block crossover study. ANIMALS: 6 healthy adult dogs. PROCEDURE: Minimal alveolar concentration of isoflurane was determined following administration of carprofen alone, butorphanol alone, carprofen and butorphanol, and neither drug (control). Anesthesia was induced with isoflurane in oxygen, and MAC was determined by use of a tail clamp method. Three hours prior to induction of anesthesia, dogs were fed a small amount of canned food without any drugs (control) or with carprofen (2.2 mg/kg of body weight [1 mg/lb]). Following initial determination of MAC, butorphanol (0.4 mg/kg [0.18 mg/lb], i.v.) was administered, and MAC was determined again. Heart rate, respiratory rate, indirect arterial blood pressure, endtidal partial pressure of CO2, and saturation of hemoglobin with oxygen were recorded at the time MAC was determined. RESULTS: Mean +/- SD MAC of isoflurane following administration of butorphanol alone (1.03 +/- 0.22%) or carprofen and butorphanol (0.90 +/- 0.21%) were significantly less than the control MAC (1.28 +/- 0.14%), but MAC after administration of carprofen alone (1.20 +/- 0.13%) was not significantly different from the control value. The effects of carprofen and butorphanol on the MAC of isoflurane were additive. There were not any significant differences among treatments in regard to cardiorespiratory data. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that administration of butorphanol alone or in combination with carprofen significantly reduces the MAC of isoflurane in dogs; however, the effects of butorphanol and carprofen are additive, not synergistic.  相似文献   
98.
Dogs were given medetomidine (10 microg/kg body weight, intramuscularly) followed in 10 minutes by either ketamine (4 mg/kg body weight, intravenously) or isoflurane mask induction and maintained on isoflurane for 30 minutes. Medetomidine induced lateral recumbency in all dogs. Endotracheal intubation was faster and smoother when dogs were given ketamine than when induced with isoflurane. Analgesia was excellent in all groups. Respiratory depression was more profound when dogs were given ketamine. Recovery quality was smooth and similar among all groups. Medetomidine-premedicated dogs could be induced with either ketamine or isoflurane and maintained on 1.3% isoflurane to achieve good analgesia with smooth recovery from anesthesia.  相似文献   
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