Comparison of the effects of methadone and butorphanol combined with acepromazine for canine gastroduodenoscopy

ObjectiveTo evaluate the feasibility of gastroduodenoscopy in dogs premedicated with acepromazine in combination with butorphanol or methadone.Study designProspective, randomized, double-blinded clinical trial.AnimalsA group of 40 client-owned dogs.MethodsDogs were randomly allocated to one of two groups and give intramuscular acepromazine 0.02 mg kg^–1 combined with either butorphanol 0.3 mg kg^–1 (group ACEBUT) or methadone 0.2 mg kg^–1 (group ACEMET). General anaesthesia was induced with propofol and ketamine and maintained with sevoflurane (2.3%) in oxygen. Cardiopulmonary variables were recorded at 5 minute intervals during anaesthesia. Feasibility of the entire gastroduodenoscopy was evaluated with a visual analogue scale (VAS) from 0 (best) to 100 (worst) (primary outcome of the study). Lower oesophageal sphincter dilatation and duodenal intubation were scored. Pylorus diameter was measured with standard endoscopic inflatable balloons. Overall cardiovascular stability was assessed during anaesthesia, using a VAS (0-100), as was the presence of fluid in the oesophagus, regurgitation, need for mechanical ventilation, and intraoperative and postoperative rescue analgesia (secondary outcomes of the study). Differences between treatments were analysed with Mann–Whitney U, Student t test, Fisher exact test or mixed model analysis of variance as appropriate. Subsequently, feasibility VAS of the gastroduodenoscopy was assessed for noninferiority between groups. The noninferiority margin was set as –10.ResultsAll gastroduodenoscopies were successfully completed in both groups using an endoscope tip diameter of 12.8 mm in all but one dog. Feasibility of gastroduodenoscopy was evaluated as 2.9 ± 5.6 in group ACEBUT and 5.1 ± 5.8 in group ACEMET. No significant differences between groups were detected in any measured or assessed variables, and noninferiority was confirmed.Conclusion and clinical relevanceIn our study population, the effects of methadone and butorphanol when combined with acepromazine were comparable.     

A longitudinal study of the effect of time on the matching performance of a retinal recognition system for lambs

While there is strong evidence supporting retinal vascular pattern as a distinctive marker for sheep, it would be advantageous to get an insight into its robustness; in other words, to determine whether retinal recognition of young animals (lambs) can reach as good a matching performance as the one demonstrated for adult sheep. To this aim, a longitudinal study was devised to observe the evolution of matching scores (ms) of lamb retinal images (n = 38) acquired from 1 to 22 weeks after birth. It was observed that four lamb retinas (out of 38) underwent slight curving of one or two secondary arteries, which ceased by the time they were 6–8 weeks old. However, this slight artery curving did not affect matching performance. A random effects statistical model demonstrated that lamb age had an effect (P < 0.01) on the matching scores produced using this commercially available retinal recognition system. As lambs grew older (larger eyes) and they became easier to handle, retinal images of progressively better quality could be obtained in a more consistent way; and thus matching scores increased from an average of 86 at the first week of life, up to an average of 96 by week 8. Dunnett simultaneous tests of means indicated that no further improvement in matching score took place once lambs were at least 6–8 weeks old, meaning that the retinal image quality became by then optimal and consistent. Although the variable retinal image quality of younger lambs (1–4 weeks old) caused a reduction in matching score, they did not lead to false non-matches in any case (considering a cut-off matching score of 70 for acceptance of a positive match). Therefore, the results of these trials have shown that, with the available technology, retinal images can be used as a robust biometric marker of lambs from 1 week of age.     

Wildlife pests of California agriculture: Regional variability and subsequent impacts on management

Numerous wildlife species are known pests of California agriculture. Effective management of these pests is required to maximize agricultural production, yet it is unclear how the importance of various wildlife pest species and associated management strategies may vary regionally throughout California. Accounting for these regional differences should yield management programs that are specifically tailored to the regions constituents and should be considered when managing wildlife pests at a more localized level. Therefore, we developed a survey to provide quantitative data on regional differences in research and management needs to better guide future research efforts in developing more effective, practical, and appropriate methods for managing wildlife pests. We found that coyotes were a more common pest in the mountain region, ground squirrels were a greater concern in the central and desert valley region, while birds were most commonly listed as pests by individuals working in multiple regions of California. Coyote damage varied regionally, with livestock depredation the greatest concern throughout most of California, although damage to irrigation tubing and sprinklers was of equal concern in the central and desert valley region. For bird pests, exclusionary devices were the most common and most effective methods of control in the coastal region. Frightening devices were the most commonly used method for bird control in all other regions, although the efficacy associated with frightening devices was considered far lower than their level of use, suggesting that better management options are needed for bird control in these regions. For all wildlife pests, nonlethal control options (e.g., exclusionary devices, habitat modification) were generally preferred in the coastal region while lethal removal options ranked higher in the central and desert valley region (e.g., baiting, burrow fumigation). Efficacy was considered the most important attribute of a control method for all regions, while Integrated Pest Management programs were considered the most effective method for controlling wildlife pests in all regions except for the central and desert valley region. Collectively, the importance of wildlife pests and the perception of associated control methods varied throughout California and reflects the need to consider these regional differences in order to optimize damage management strategies at the regional level.     

Disturbances Impact on Longevity of Grass Seeds,Semi-Arid South African Rangeland

The effect of plant and soil disturbances on seed density, species richness, and seed longevity of the soil seed bank was quantified for a semi-arid rangeland, over a 5-yr period (2002/2003–2006/2007 growing seasons). The different soil and plant treatments included fire, tillage (intended as a trampling surrogate), and blocked seed rain (simulating heavy grazing). These three experimental factors were combined in a factorial arrangement. Seed responses were evaluated in the soil seed bank before the new seed set, after the first seed production event, and after the second seed production event. Before disturbance (physical impact on the plant and soil), soil seed bank was dominated by early successional species: conversely, aboveground vegetation was mainly dominated by perennial grasses. After only 4 yr of blocked seed rain, seedling emergence of Decreaser grass species ceased totally both in the field and seed bank, with lower effect on Increaser grass species. Emergence of both Decreaser and Increaser grass species decreased in the seed bank with tillage, whereas the opposite occurred in the field. By contrast, tillage increased the emergence of weeds in the seed bank. The decrease in emergence of Decreaser grass species in both seed bank and field was still evident 4 yr after the rangeland was burnt. The grass species Themeda triandra was the most sensitive to fire in terms of seedling emergence. Blocked seed rain treatment significantly decreased (P < 0.05) species richness. Regardless of treatments applied, there was poor similarity between aboveground vegetation and the associated seed bank. Differences in the soil seed bank are likely to reflect manifested properties rather than short-term changes. Several characteristics of seed banks (species composition, seed abundance, and longevity) must be considered in order to understand the dynamics of plant communities following disturbances.