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121.
The role of ketamine (K) in pain management is controversial. It is reported to provide visceral analgesia in cats. This study aimed to assess its somatic actions using a thermal threshold (TT) model. Six cats (four spayed females, two castrated males, 4.3–7.2 kg) participated in the study. The day before each study, the thorax of each of the cats was shaved and a cephalic catheter was placed. TT was measured using a device specifically developed for cats. A heater element and temperature sensor housed in a small probe were held against the thorax of the cats with an elastic band and pressure bladder to assure consistent contact. The skin temperature was recorded before each test, then the heater was activated. When the cat responded by flinching, turning, or jumping, the stimulus was terminated and the threshold temperature was recorded. Treatments were 2 mg kg?1 of K (10 mg mL?1), or 0.2 mL kg?1 of saline (S) IV, given in a randomized cross‐over design with at least 1 week between treatments. The investigator was blinded to the treatment. TT was measured thrice before treatment (baseline threshold) at 15 minutes, then every 30 minutes for 8 hours and once at 24 hours after injection. Data were analyzed using a four‐factor anova . Cats were sedated for 45 minutes following K treatment. There was no difference in baseline TT between treatments (K = 41.9 ± 1.7 °C, S = 41.0 ± 1.45 °C), and no change in TT at any time in the S group. TT increased significantly at 15 and 30 minutes after K, then decreased below baseline values between 210 and 390 minutes, with a nadir of 38.8 ± ± 1.05 °C at 390 minutes. During this time period, cats exhibited normal activity, but responses to thermal stimuli were exaggerated. This study suggested that K caused a delayed onset hyperalgesia in cats.  相似文献   
122.
Prostaglandin F receptors (PGF Rs) were measured in bovine corpus luteum and myometrial cell membranes using a radiometric method. The inhibition of labelled PGF binding exerted by d-cloprostenol, dl-cloprostenol, PGF and PGE1 (l0–11 M to 10–4 M) was evaluated in vitro. Results strongly suggest that cloprostenol binding to PGFRs is stereospecific. d-Cloprostenol and PGF were equipotent, about 150 times more potent than d-cloprostenol (P < 0.05) and approximately 280 times more potent than PGE, (P < 0.05) in inhibiting [3H]PGF binding to corpus luteum cell membranes. Such differences were less evident in myometrial cell membranes, where d-cloprostenol and PGF were about 10 times more potent than d-cloprostenol (P < 0.05) and approximately 95 times more potent than PGEl (P < 0.05).  相似文献   
123.
Summary A comparison has been made in 9- to 10-month-old castrated male Merino sheep of the changes in plasma total cortisol concentration and behaviour after being treated by either the modified Mules operation or by topical application of a quaternary ammonium compound to achieve non-surgical mulesing. After surgical mulesing, plasma total cortisol concentration increased immediately and rapidly and reached a peak value in 15 minutes, whereas after non-surgical treatment an immediate rise did not occur, but a similar peak value was observed in blood samples collected 24 hours after treatment. The concentrations were lower in both groups at 48 hours. Likewise postural changes indicative of discomfort were immediately apparent in the surgically treated sheep, but not until 3 to 4 hours later in those treated non-surgically. Arena testing revealed that a lasting aversion to the person who restrained them during treatment developed in the surgically mulesed sheep, but not in those treated non-surgically. The non-surgical procedure did not create large open wounds, as did the surgical operation, but still achieved similar enlargement of the bare area on the breech, and healing was quicker in the non-surgically treated sheep.  相似文献   
124.
This paper discusses the methods which veterinarians in Australia use to calculate their fees and charges. Problems associated with these methods and the tendency to undervalue the professional component of veterinary services are discussed. The paper introduces the concept of a relative value study of veterinary professional services within Australia and recommends the development of a relative value scale and conversion factors, based on appropriate resource cost accounting methodology, as a method to quantify veterinary professional service charges. A relative value scale is a table of "weights" that defines the relative value of procedures or services one to the other. A conversion factor is used to change the relative value unit to a dollar price and thus convert a relative value scale to a fee schedule. The Australian Veterinary Association is suggested as the most appropriate organisation to initiate and co-ordinate the research necessary for the development of these recommendations on a national basis.  相似文献   
125.
Objective To confirm the efficacy of ivermectin released from a controlled-release capsule administered to young sheep and to breeding ewes under field conditions. Design Randomised field trials. Procedure In each of ten field trials 25 weaned lambs were treated with ivermectin controlled-release capsules and 25 remained untreated. Eight similar field trials were conducted using adult ewes. Efficacy against infections of gastrointestinal nematodes was assessed by faecal egg counts and faecal larval culture. Body weights were recorded and faecal soiling of the breech wool (dags) was assessed. Results Nematode faecal egg counts in the two groups were not different (P = 0.13) before treatment in the weaner trials or before treatment in the ewe trials (P = 0.49), but thereafter eggs in the untreated sheep persisted, whereas counts in sheep given capsules were negligible (P ≤ 0.01). In the weaner trials, dag scores for the two groups were not different at the start of the trials (P = 0.18) but at the end, untreated sheep had significantly more dags (P = 0.04) than treated sheep. In the ewe trials, dag scores remained low in both groups. Weaners treated with the capsule gained 1.4 kg (95% CL: 0.7, 3.1) more weight over the 16 week trial period compared to untreated weaners (P = 0.01). Both groups of ewes lost weight as a result of parturition but the mean loss by week 16 was greater for untreated (3.7 kg) (95% CL: -5.1,-2.2) than for treated ewes (1.8 kg) (95% CL: -3.3, -0.4). The mean change in ewe body weight for the two groups was however not significant (P = 0.07). Differentiation of nematode larvae recovered from cultures of faeces from untreated animals indicated that the capsules were effective against the common parasites of sheep. Conclusion The capsule was efficacious against gastrointestinal nematodes judging from faecal egg counts. It has the potential to significantly reduce contamination of pasture with nematode eggs. Treated weaners had less dags for 16 weeks and gained more weight than untreated weaners.  相似文献   
126.
Contrast fluoroscopy is a valuable tool to examine avian gastrointestinal motility. However, the lack of a standardized examination protocol and reference ranges prevents the objective interpretation of motility disorders and other gastrointestinal abnormalities. Our goals were to evaluate gastrointestinal motility in 20 Hispaniolan Amazon parrots (Amazona ventralis) by contrast fluoroscopy. Each parrot was crop‐fed an equal part mixture of barium sulfate and hand‐feeding formula and placed in a cardboard box for fluoroscopy. Over a 3‐h period, 1.5 minute segments of lateral and ventrodorsal fluoroscopy were recorded every 30 min. The gastric cycle and patterns of intestinal motility were described. The frequency of crop contractions, esophageal boluses, and gastric cycles were determined in lateral and ventrodorsal views. A range of 3.4–6.6 gastric cycles/min was noted on the lateral view and 3.0–6.6 gastric cycles/min on the ventrodorsal view. Circular measurements of the proventriculus diameter, ventriculus width, and length were obtained using the midshaft femoral diameter as a standard reference unit. The upper limits of the reference ranges were 3.6 and 4.7 femoral units for the proventriculus diameter in the lateral and ventrodorsal view, respectively. Two consecutive measurements were obtained and the measurement technique was found to have high reproducibility. In this study, we established a standardized protocol for contrast fluoroscopic examination of the gastrointestinal tract and a reliable measurement method of the proventriculus and ventriculus using femoral units in the Hispaniolan Amazon parrot.  相似文献   
127.
Javsicas, LH., Giguère, S., Womble, AY. Disposition of oral telithromycin in foals and in vitro activity of the drug against macrolide‐susceptible and macrolide‐resistant Rhodococcus equi isolates. J. vet. Pharmacol. Therap. doi: 10.1111/j.1365‐2885.2009.01151.x. The objectives of this study were to determine the serum and pulmonary disposition of telithromycin in foals and to determine the minimum inhibitory concentration (MIC) of telithromycin against macrolide‐susceptible and macrolide‐resistant Rhodococcus equi isolates. A single dose of telithromycin (15 mg/kg of body weight) was administered to six healthy 6–10‐week‐old foals by the intragastric route. Activity of telithromycin was measured in serum, pulmonary epithelial lining fluid (PELF), and bronchoalveolar lavage (BAL) cells using a microbiological assay. The broth macrodilution method was used to determine the MIC of telithromycin, azithromycin, clarithromycin and erythromycin against R. equi. Following intragastric administration, mean ± SD time to peak serum telithromycin activity (Tmax) was 1.75 ± 0.76 h, maximum serum activity (Cmax) was 1.43 ± 0.37 μg/mL, and terminal half‐life (t½) was 3.81 ± 0.40 h. Telithromycin activity, 4 h postadministration was significantly higher in BAL cells (50.9 ± 14.5 μg/mL) than in PELF (5.07 ± 2.64 μg/mL), and plasma (0.84 ± 0.25 μg/mL). The MIC90 of telithromycin for macrolide‐resistant R. equi isolates (8 μg/mL) was significantly higher than that of macrolide‐susceptible isolates (0.25 μg/mL). The MIC of telithromycin for macrolide‐resistant isolates (MIC50 = 4.0 μg/mL) was significantly lower than that of clarithromycin (MIC50 = 24.0 μg/mL), azithromycin (MIC50 =256 μg/mL) and erythromycin (MIC50 = 24 μg/mL).  相似文献   
128.
Studies on failure of T strain live Babesia bovis vaccine   总被引:1,自引:0,他引:1  
SUMMARY Field investigations of the protection afforded by the Australian live Babesia bovis vaccine used in the early 1990s (T strain) revealed inadequate vaccine-induced protection in certain herds. Vaccination/challenge trials using 207 experimental cattle were conducted to evaluate the protection afforded by T strain B bovis against field isolates from these herds. The trials investigated whether isolates that could ‘break-through’ T strain immunity were present in the field, the ability or inability of specific cattle to develop protective immunity after vaccination with T strain and the effect of attenuation and maintenance procedures on the immunogenicity of T strain. The results showed that B bovis parasites present early in the process of attenuation of T strain were more protective than those remaining late in the process. They also showed that cattle from properties experiencing vaccine failures were less protected by T strain vaccination than Bos taurus cattle randomly selected from the general population if vaccinated with highly attenuated T strain. A hypothesis is offered to explain these findings .  相似文献   
129.
OBJECTIVE: To evaluate the anesthetic and cardiorespiratory effects of two doses of intramuscular xylazine/ketamine in llamas, and to determine if an intramuscular injection of tolazoline would shorten the anesthesia recovery time. STUDY DESIGN: Prospective randomized study. ANIMALS: Six castrated male llamas. METHODS: Each llama received a low dose (LD) (0.4 mg kg(-1) xylazine and 4 mg kg(-1) ketamine) and high dose (HD) (0.8 mg kg(-1) xylazine and 8 mg kg(-1) ketamine). Time to sedation, duration of lateral recumbency and analgesia, pulse, respiratory rate, hemoglobin oxygen saturation, arterial blood pressure, blood gases, and the electrocardiogram were monitored and recorded during anesthesia. Three llamas in each treatment were randomized to receive intramuscular tolazoline (2 mg kg(-1)) after 30 minutes of lateral recumbency. RESULTS: Onset of sedation, lateral recumbency, and analgesia was rapid with both treatments. The HD was able to provide at least 30 minutes of anesthesia in all six llamas. The LD provided only 30 minutes of anesthesia in two out of six llamas. Respiratory depression and hypoxemia were seen in the HD treatment during the first 10 minutes of lateral recumbency. Two llamas were severely hypoxemic during this period and were given nasal oxygen for five minutes. Heart rate decreased, but there were no significant changes in blood pressure. Tolazoline significantly shortened the duration of recumbency in the HD treatment. CONCLUSIONS: The HD provided more consistent clinical effects in llamas than did the LD. Intramuscular tolazoline shortens the duration of lateral recumbency in llamas anesthetized with this combination. CLINICAL RELEVANCE: Both doses appear to be very effective in providing restraint in llamas. The LD may be used for procedures requiring a short period of anesthesia or restraint. The HD could be used when a longer duration of anesthesia is desired. Supplemental oxygen should be available if using the HD. Tolazoline (IM) shortened the recovery time with this combination in llamas.  相似文献   
130.
OBJECTIVE: To evaluate effects of medetomidine on anesthetic dose requirements, cardiorespiratory variables, plasma cortisol concentrations, and behavioral pain scores in dogs undergoing ovariohysterectomy. DESIGN: Randomized, prospective study. ANIMALS: 12 healthy Walker-type hound dogs. PROCEDURE: Dogs received medetomidine (40 micrograms/kg [18.2 micrograms/lb] of body weight, i.m.; n = 6) or saline (0.9% NaCl) solution (1 ml, i.m.; 6) prior to anesthesia induction with thiopental; thiopental dose needed for endotracheal intubation was compared between groups. Ovariohysterectomy was performed during halothane anesthesia. Blood samples were obtained at various times before drug administration until 300 minutes after extubation. Various physiologic measurements and end-tidal halothane concentrations were recorded. RESULTS: In medetomidine-treated dogs, heart rate was significantly lower than in controls, and blood pressure did not change significantly from baseline. Plasma cortisol concentrations did not increase significantly until 60 minutes after extubation in medetomidine-treated dogs, whereas values in control dogs were increased from time of surgery until the end of the recording period. Control dogs had higher pain scores than treated dogs from extubation until the end of the recording period. CONCLUSION AND CLINICAL RELEVANCE: Administration of medetomidine reduced dose requirements for thiopental and halothane and provided postoperative analgesia up to 90 minutes after extubation. Dogs undergoing ovariohysterectomy by use of thiopental induction and halothane anesthesia benefit from analgesia induced by medetomidine administered prior to anesthesia induction. Additional analgesia is appropriate 60 minutes after extubation.  相似文献   
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