In vitro study of heat production during power reduction of equine mandibular teeth     

Allen ML  Baker GJ  Freeman DE  Holmes KR  Marretta SM  Scoggins RD  Constable P 《Journal of the American Veterinary Medical Association》2004,224(7):1128-1132

OBJECTIVE: To measure the amount of heat generated during 3 methods of equine dental reduction with power instruments. DESIGN: In vitro study. SAMPLE POPULATION: 30 premolar and molar teeth removed from mandibles of 8 equine heads collected at an abbatoir. PROCEDURE: 38-gauge copper-constantan thermocouples were inserted into the lingual side of each tooth 15 mm (proximal) and 25 mm (distal) from the occlusal surface, at a depth of 5 mm, which placed the tip close to the pulp chamber. Group-NC1 (n = 10) teeth were ground for 1 minute without coolant, group-NC2 (10) teeth were ground for 2 minutes without coolant, and group-C2 (10) teeth were ground for 2 minutes with water for coolant. RESULTS: Mean temperature increase was 1.2 degrees C at the distal thermocouple and 6.6 degrees C at the proximal thermocouple for group-NC1 teeth, 4.1 degrees C at the distal thermocouple and 24.3 degrees C at the proximal thermocouple for group-NC2 teeth, and 0.8 degrees C at the distal thermocouple and -0.1 degrees C at the proximal thermocouple for group-C2 teeth. CONCLUSIONS AND CLINICAL RELEVANCE: In general, an increase of 5 degrees C in human teeth is considered the maximum increase before there is permanent damage to tooth pulp. In group-NC2 teeth, temperature increased above this limit by several degrees, whereas in group-C2 teeth, there was little or no temperature increase. Our results suggest that major reduction of equine teeth by use of power instruments causes thermal changes that may cause irreversible pulp damage unless water cooling is used.  相似文献   

Prevalence of Salmonella spp on conventional and organic dairy farms     

Fossler CP  Wells SJ  Kaneene JB  Ruegg PL  Warnick LD  Bender JB  Godden SM  Halbert LW  Campbell AM  Zwald AM 《Journal of the American Veterinary Medical Association》2004,225(4):567-573

OBJECTIVE: To describe the occurrence of fecal shedding, persistence of shedding over time, and serogroup classification of Salmonella spp on a large number of dairy farms of various sizes. DESIGN: Longitudinal study. SAMPLE POPULATION: 22,417 fecal samples from cattle and 4,570 samples from the farm environment on 110 organic and conventional dairy farms in Minnesota, Wisconsin, Michigan, and NewYork. PROCEDURE: 5 visits were made to each farm at 2-month intervals from August 2000 to October 2001. Fecal samples from healthy cows, calves, and other targeted cattle groups and samples from bulk tank milk, milk line filters, water, feed sources, and pen floors were collected at each visit. Bacterial culture was performed at 1 laboratory. RESULTS: Salmonella spp were isolated from 4.8% of fecal samples and 5.9% of environmental samples; 92.7% of farms had at least 1 Salmonella-positive sample. The 75th percentile for median within-herd prevalence of Salmonella spp in cattle for 5 sampling visits to a given farm was 2.0% and for maximum within-herd prevalence of Salmonella spp was 13.6%. Farms with a median within-herd prevalence of Salmonella spp of > or = 2.0% accounted for 76.3% of Salmonella-positive samples. There was no significant difference in the prevalence of Salmonella spp between conventional and organic farms. Seasonal differences in Salmonella shedding were observed. More farms had at least 1 serogroup B isolate than any other serogroup, whereas serogroup E1 was the most common among all Salmonella-positive samples. More than 1 serogroup was isolated on 76.4% of Salmonella-positive farms. CONCLUSIONS AND CLINICAL RELEVANCE: Salmonella spp were isolated from > 90% of dairy farms; however, 25% of farms accounted for > 75% of Salmonella-positive samples. This information is critical for the direction of intervention strategies to decrease the prevalence of Salmonella spp on dairy farms.  相似文献   

Progressive ataxia of Charolais cattle     

Millar M  Scholes S  Morris M 《The Veterinary record》2004,154(12):379

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The first record in the Americas of an autochthonous case of Leishmania (Leishmania) infantum chagasi in a domestic cat (Felix catus) from Cotia County, São Paulo State, Brazil     

Savani ES  de Oliveira Camargo MC  de Carvalho MR  Zampieri RA  dos Santos MG  D'Auria SR  Shaw JJ  Floeter-Winter LM 《Veterinary parasitology》2004,120(3):229-233

A case of feline cutaneous leishmaniasis is reported in a domestic cat (Felis catus) as an apparently natural infection in a non-endemic area. Amastigotes were seem in smears of a nodular lesion on the cat's nose. No parasite could be seen in cytological preparations of liver or spleen but DNA obtained from a sample of the spleen produced the expected fragment in a Leishmania specific rDNA based PCR assay. The PCR product, a 520 bp fragment, was sequenced and the nucleotide sequence was identical to that of Leishmania (Leishmania) infantum chagasi. These results are surprising since no autochthonous human or canine cases of visceral leishmaniasis have ever been reported from this region. This case suggests that natural transmission of this disease is occurring in this area, and that cats could act as a reservoir of L. (L.) infantum chagasi.  相似文献   

Assessment of antibody avidity in aborting cattle by a somatic Neospora caninum tachyzoite antigen IgG avidity ELISA     

Sager H  Gloor M  Björkman C  Kritzner S  Gottstein B 《Veterinary parasitology》2003,112(1-2):1-10

A Neospora caninum IgG avidity ELISA was carried out on the basis of a somatic N. caninum tachyzoite antigen. The test was validated using experimentally infected calves, where a clear maturation of the IgG avidity over time could be demonstrated. At a maximum of 82 days after infection (d.p.i.), all animals showed antibody avidities ranging above 35%, and respective sera were thus defined as highly avid.Sera of 103 naturally infected seropositive cows with abortion (N. caninum association was provided by a N. caninum PCR-positivity of the fetus in 40 cases) and 139 seropositive animals without abortion history were concurrently examined. Significantly lower avidities were observed in aborting cows when compared to animals without abortion problems (P<0.01). While the avidity of sera collected before abortion remained practically constant until abortion, a significant increase of avidity could be observed in samples collected weeks to months after abortion (P<0.01).The avidities of non-aborting animals from farms with or without abortion problems did not differ significantly with time and were mainly located in the high avidity area. These data indicate that low avidities are not necessarily linked to recent N. caninum infection but can also be an indicator for increased abortion risk in cattle.  相似文献   

Evaluation of ground reaction forces produced by chickens walking on a force plate     

Corr SA  McCorquodale CC  McGovern RE  Gentle MJ  Bennett D 《American journal of veterinary research》2003,64(1):76-82

OBJECTIVE: To evaluate the use of a force plate as a method for objective gait analysis in adult poultry, to characterize ground reaction forces (GRFs) produced in adult chickens during normal walking, and to assess the variability of GRFs. ANIMALS: 18 clinically normal 5-month-old Brown Leghorn hens. PROCEDURE: Vertical, craniocaudal, and mediolateral GRFs were measured as hens walked across a standard force plate embedded in the middle of a runway. RESULTS: All GRFs were significantly affected by speed, and variability was high. With increasing speed, overall stance time decreased, but the percentage of stance time spent in braking or propulsion remained approximately equal. There was an overall increase in maximum propulsion force, which was produced at a greater rate over a shorter time; thus, propulsion integral decreased. Maximum braking forces and braking integrals were variable, but the rate at which the forces were generated increased. Mediolateral forces were 2 to 3 times greater in hens than values that have been reported for other species. CONCLUSIONS AND CLINICAL RELEVANCE: A standard force plate can be used to objectively measure GRFs in walking adult hens; however, the large variation in the data suggests that the technique in its current form would be of limited clinical use. Overall, vertical and craniocaudal forces had similar characteristics to those of other species, whereas mediolateral forces were found to be much greater in chickens than for other species.  相似文献   

Use of a live attenuated Salmonella typhimurium vaccine to protect hens against Salmonella enteritidis infection while undergoing molt     

Holt PS  Gast RK  Kelly-Aehle S 《Avian diseases》2003,47(3):656-661

Previous studies demonstrated that Salmonella enteritidis infections in hens undergoing molt via feed withdrawal were more severe than in full fed hens. We conducted two trials to determine if immunizing specific-pathogen-free, Salmonella-culture-negative hens via aerosol exposure to MeganVacl, a commercially available attenuated Salmonella typhimurium vaccine, would reduce transmission of S. enteritidis from infected hens to uninfected but contact-exposed hens during a molt. In trial 1, one group of hens received two aerosol doses of vaccine 2 wk apart whereas a second group of hens remained nonvaccinated. In trial 2, the vaccinated group received only one dose of vaccine. Two weeks after the final immunization, feed was removed from all the hens, and on day 4, the center hen in rows of 11 hens received a dose of 3 x 10(5) (trial 1) or 1.3 x 10(6) (trial 2). Transmission to the unchallenged hens was followed 3, 10, 17, and 24 days later. Vaccination reduced the horizontal spread of S. enteritidis in vaccinated hens compared with their nonvaccinated counterparts, with vaccinated hens shedding significantly less S. enteritidis on day 10 postchallenge in trial 1 and on days 3, 10, 17, and 24 in trial 2. Recovery of S. enteritidis from ovaries was significantly reduced in the vaccinated hens in trial 1 and from livers/spleens, ovaries, and cecum in trial 2. These studies indicate that immunization of hens with a live S. typhimurium vaccine could help reduce S. enteritidis problems during a molt situation.  相似文献   

Use of noninvasive dental dolorimetry to evaluate analgesic effects of intravenous and intrathecal administration of morphine in anesthetized dogs     

Brown DC  Bernier N  Shofer F  Steinberg SA  Perkowski SZ 《American journal of veterinary research》2002,63(10):1349-1353

OBJECTIVE: To determine whether changes in amplitude of the reflex-evoked muscle action potential (REMP) elicited by noninvasive dental dolorimetry (electrical stimulation of the tooth pulp) in anesthetized dogs may be used to objectively evaluate the effectiveness of IV and intrathecal (IT) administration of morphine. ANIMALS: 6 male Beagles that were 2 to 6 years old. PROCEDURE: Dogs were used in a crossover design with at least a 5-day washout period between treatments. Each dog received morphine, saline (0.9% NaCl) solution, and oxytocin via the IV and IT routes of administration; however, only results for morphine and saline treatments were reported here. Dogs were anesthetized and prepared for noninvasive dental dolorimetry. After IV or IT administration, electrical stimulation was applied to a tooth, and REMPs of the digastricus muscle were recorded at 5-minute intervals for 60 minutes. To determine differences in REMP amplitude between treatments, a linear regression line was fitted for each dog-treatment combination. RESULTS: The IV administration of morphine significantly inhibited REMP amplitude, compared with IV administration of saline solution. Intrathecal administration of morphine significantly inhibited REMP amplitude, compared with IT administration of saline solution. CONCLUSIONS AND CLINICAL RELEVANCE: Noninvasive dental dolorimetry in anesthetized dogs has promise as a technique for use in evaluating the analgesic potential of drugs administered IV and IT through evaluation of their effect on REMP amplitude recorded for the digastricus muscle.  相似文献   

Surveillance for porcine proliferative enteropathy in Alberta by using routine diagnostic laboratory data          下载免费PDF全文

Wilson JB  Honour S  Pauling GE  O'Connor B  Benjamin M  Paradis MA  Dick CP 《The Canadian veterinary journal. La revue veterinaire canadienne》2002,43(8):604-606

Data from the Food Safety Division, Alberta Agriculture, Food and Rural Development were analyzed to determine the frequency of diagnosis of porcine proliferative enteropathy (PPE) relative to the diagnosis of other porcine enteric infections between 1993 and 1997. Next to colibacillosis, PPE was the most commonly diagnosed enteric disease among those reported.  相似文献   

Comparison of two heated gutta-percha obturation techniques of the mandibular first molar in the dog     

Ulbricht RD  Marretta SM  Baker GJ  Siegel AM  Klippert LS 《Journal of veterinary dentistry》2002,19(2):63-70

An in vitro study compared two heated gutta-percha obturation techniques of the mandibular first molar in the dog. Thirty hemimandibles were harvested from adult dog cadavers. The mandibular first molars were instrumented and obturated using either the ThermaFil Plus technique or the SuccessFil vertical compaction technique. Obturation times were recorded and three radiographic views were taken of all teeth for evaluation of the endodontic fill. Fifty-two of the mandibular first molar roots were evaluated in the apical dye leakage portion of the study. The ThermaFil Plus obturation technique required less time and provided a better radiographic endodontic fill, however there was significantly greater apical dye leakage in this technique compared with teeth that were obturated using the SuccessFil vertical compaction technique.  相似文献