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Assessment of microcirculatory changes by use of sidestream dark field microscopy during hemorrhagic shock in dogs
2011
Peruski, Ann M. | Cooper, Edward S.
Objective—To directly assess microcirculatory changes associated with induced hemorrhagic shock by use of sidestream dark field microscopy (SDM) and correlate those values with concurrently measured macrovascular and blood gas variables in healthy anesthetized dogs. Animals—12 adult dogs. Procedures—Dogs were anesthetized and splenectomized. Instrumentation and catheterization were performed for determination of macrohemodynamic and blood gas variables. Hemorrhagic shock was induced via controlled hemorrhage to a mean arterial blood pressure (MAP) of 40 mm Hg. Dogs were maintained in the shock state (MAP, 35 to 45 mm Hg) for 60 minutes. An SDM device was used to image microcirculation of buccal mucosa, and vascular analysis software was used to determine microcirculatory variables. These values were compared with other cardiovascular and blood gas variables to determine correlations. Results—Following hemorrhage, there was a significant decrease in microvascular variables (mean ± SD), including proportion of perfused vessels (82.77 ± 8.32% vs 57.21 ± 28.83%), perfused vessel density (14.86 ± 2.64 mm/m2 vs 6.66 ± 4.75 mm/m2), and microvascular flow index (2.54 ± 0.52 vs 1.59 ± 0.85). Perfused vessel density individually correlated well with macrovascular variables, with heart rate (zero order, partial correlation, and part correlation coefficients = −0.762, −0.884, and −0.793, respectively) and oxygen extraction ratio (−0.734, −0.832, and −0.746, respectively) being the most important predictors. Conclusions and Clinical Relevance—SDM allowed real-time imaging of the microvasculature and has potential as an effective tool in experimental and clinical applications for monitoring microcirculatory changes associated with hemorrhagic shock and resuscitation in dogs.
Показать больше [+] Меньше [-]Telemetric measurement of body core temperature in exercising unconditioned Labrador retrievers
2011
Angle, T Craig | Gillette, Robert L.
This project evaluated the use of an ingestible temperature sensor to measure body core temperature (Tc) in exercising dogs. Twenty-five healthy, unconditioned Labrador retrievers participated in an outdoor 3.5-km run, completed in 20 min on a level, 400-m grass track. Core temperature was measured continuously with a telemetric monitoring system before, during, and after the run. Data were successfully collected with no missing data points during the exercise. Core temperature elevated in the dogs from 38.7 +/- 0.3 degrees C at pre-exercise to 40.4 +/- 0.6 degrees C post-exercise. While rectal temperatures are still the standard of measurement, telemetric core temperature monitors may offer an easier and more comfortable means of sampling core temperature with minimal human and mechanical interference with the exercising dog.
Показать больше [+] Меньше [-]Presence and characterization of Campylobacter jejuni in organically raised chickens in Quebec
2011
Thibodeau, Alexandre | Fravalo, Philippe | Laurent-Lewandowski, Sylvette | Guévremont, Evelyne | Quessy, Sylvain | Letellier, Ann
The objective of this study was to estimate the presence of the important foodborne pathogen Campylobacter jejuni in organically raised chickens in the province of Quebec. The recovered isolates were further characterized for their antimicrobial resistance profile, autoagglutination property and chemotaxis. Antimicrobial resistance was evaluated using agar dilution for: tetracycline, erythromycin, chloramphenicol, ciprofloxacin, gentamicin, nalidixic acid, clindamycin, ampicillin, azithromycin, bacitracin, and ceftiofur. Autoagglutination was measured by monitoring optical density changes in a bacterial suspension after 3 h of incubation at room temperature. Chemotaxis was evaluated after a contact time of 3 h between isolates and mucin, using a quantitative protocol. A total of 10 lots of chickens was sampled in August and September 2009; half of them were positive for the presence of C. jejuni. Antimicrobial resistance was found only for tetracycline (44%), erythromycin (6%), azithromycin (6%) and clindamycin (2%). Variation was observed in the minimum inhibitory concentrations (MICs) for ceftiofur and bacitracin, for which C. jejuni possess intrinsic resistance. Autoagglutination and chemotaxis varied among isolates and lot-level differences in these were observed. Autoagglutination and chemotaxis levels appeared as independent isolate properties. Further monitoring and characterization of isolates originating from organic chickens is of interest since this type of production might represent another source of exposure of consumers to a variety of the foodborne pathogen C. jejuni.
Показать больше [+] Меньше [-]Predictive risk mapping of West Nile virus (WNV) infection in Saskatchewan horses
2011
Epp, Tasha Y. | Waldner, Cheryl | Berke, Olaf
The objective of this study was to develop a model using equine data from geographically limited surveillance locations to predict risk categories for West Nile virus (WNV) infection in horses in all geographic locations across the province of Saskatchewan. The province was divided geographically into low-, medium-, or high-risk categories for WNV, based on available serology information from 923 horses obtained through 4 studies of WNV infection in horse populations in Saskatchewan. Discriminant analysis was used to build models using the observed risk of WNV in horses and geographic division-specific environmental data as well as to predict the risk category for all areas, including those beyond the surveillance zones. High-risk areas were indicated by relatively lower rainfall, higher temperatures, and a lower percentage of area covered in trees, water, and wetland. These conditions were most often identified in the southwest corner of the province. Environmental conditions can be used to identify those areas that are at highest risk for WNV. Public health managers could use prediction maps, which are based on animal or human information and developed from annual early season meteorological information, to guide ongoing decisions about when and where to focus intervention strategies for WNV.
Показать больше [+] Меньше [-]Exposure to infectious agents in dogs in remote coastal British Columbia: Possible sentinels of diseases in wildlife and humans
2011
Bryan, Heather M. | Darimont, Chris T. | Paquet, Paul C. | Ellis, John A. | Goji, Noriko | Gouix, Maelle | Smits, Judit E.
Ranked among the top threats to conservation worldwide, infectious disease is of particular concern for wild canids because domestic dogs (Canis familiaris) may serve as sources and reservoirs of infection. On British Columbia’s largely undeveloped but rapidly changing central and north coasts, little is known about diseases in wolves (Canis lupus) or other wildlife. However, several threats exist for transfer of diseases among unvaccinated dogs and wolves. To gain baseline data on infectious agents in this area, including those with zoonotic potential, we collected blood and stool samples from 107 dogs in 5 remote communities in May and September 2007. Serology revealed that the dogs had been exposed to canine parvovirus, canine distemper virus, Bordetella bronchiseptica, canine respiratory coronavirus, and Leptospira interrogans. No dogs showed evidence of exposure to Ehrlichia canis, Anaplasma phagocytophilum, Borrelia burgdorferi, Dirofilaria immitis, or Cryptococcus gattii. Of 75 stool samples, 31 contained at least 1 parasitic infection, including Taeniid tapeworms, the nematodes Toxocara canis and Toxascaris leonina, and the protozoans Isospora sp., Giardia sp., Cryptosporidium sp., and Sarcocystis sp. This work provides a sound baseline for future monitoring of infectious agents that could affect dogs, sympatric wild canids, other wildlife, and humans.
Показать больше [+] Меньше [-]Associations among behavioral and acute physiologic responses to lipopolysaccharide-induced clinical mastitis in lactating dairy cows
2011
Zimov, Jennifer L. | Botheras, Naomi A. | Weiss, William P. | Hogan, Joseph S.
Objective—To examine behavioral and physiologic effects of lipopolysaccharide (LPS)-induced mastitis in lactating dairy cows. Animals—20 Holstein cows. Procedures—Cows were assigned to 5 blocks (4 cows/block) on the basis of parity and number of days in lactation. Intramammary infusion and IV treatments were assigned in a 2 × 2 factorial arrangement. Cows within each block were assigned to receive intramammary infusion with 25 μg of LPS or sterile PBS solution 3 hours after milking, and treatment with flunixin meglumine or sterile PBS solution was administered IV 4 hours after intramammary infusion. Video monitoring was continuously performed during the study. Results—LPS-infused cows spent less time during the first 12 hours after infusion lying, eating, and chewing cud, compared with results for PBS solution-infused cows. Behavioral responses were correlated with physiologic responses for the first 12 hours after intramammary infusion. Flunixin meglumine administration after intramammary infusion mitigated some behavioral and clinical systemic responses. Conclusions and Clinical Relevance—Intramammary infusion of LPS caused changes in both behavioral and physiologic variables in lactating dairy cows. Time spent lying, eating, and chewing cud were negatively correlated with physiologic responses in cows. Evaluation of behavior patterns may provide an ancillary measure, along with evaluation of physiologic variables, for monitoring well-being, clinical responses, and recovery from acute clinical mastitis.
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