EFFECTS OF SEDATION WITH MIDAZOLAM AND BUTORPHANOL ON RESISTIVE AND PULSATILITY INDICES IN HEALTHY DOGS

Resistive index (RI) and pulsatility index (PI) are indirect measurements of blood flow resistance that may be measured by pulsed wave Doppler ultrasonography. Chemical restrain may potentially alter the indices although it is required to perform ultrasonography in some patients. The purpose of this study was to describe values for both intrarenal and ocular RI and PI within the same subject in clinically normal dogs sedated with a midazolam and butorphanol combination and evaluate if there are any significant changes between sedated and nonsedated dogs. Fifteen healthy Beagle dogs were studied by Duplex Doppler interrogation in interlobar or arcuate arteries of the kidney and long posterior ciliary artery. Pulse rate and systolic blood pressure were also determined. All measurements were recorded before and after the administration of a sedative combination of midazolam (0.2 mg/kg) and butorphanol (0.2 mg/kg). Mean comparison tests (paired t-tests or Wilcoxon's rank-sum test) were used to determine if any significant differences existed between right and left renal values or right and left ocular values. A correlation study (Pearson or Spearman) was applied between RI, PI, and systolic pressure, and pulse rate. RI and PI were significantly higher in sedated Beagles than in unsedated Beagles. There was neither correlation between index and systolic blood pressure nor pulse rate. In conclusion, provided that normal RI and PI increase in sedated animals, then reference ranges should be higher when sedated--healthy or ill--animals are evaluated.     

OBSERVATIONS ON THE EFFECTS OF XYLAZINE IN NATURALLY AND ARTIFICIALLY REARED CALVES

ABSTRACT
Xylazine, when administered to calves separated from the cow at birth, in a dose recommended to cause recumbency, had the desired sedative effect within five minutes. When the same dose was administered to calves reared naturally on their dams, i.e. suckled, the sedative effect was greatly attenuated. The results suggest that the early-weaning of calves and its associated rearing procedures can modify the pharmacology of the central nervous system; in particular their response to a sedative such as xylazine.     

EFFECTS OF POSTMYELOGRAPHIC REMOVAL OF METRIZAMIDE IN DOGS

Using a paired crossover trial, the effects of postmyelographic removal of metrizamide injected via the cerebellomedullary cistern were studied in 16 normal dogs. Each animal received a routine and a withdrawal myelogram. Seizure activity, changes in spinal evoked motor potentials and body temperature were measured following each myelogram. The amount of metrizamide removed was determined by densitometrically analyzing radiographs of cerebrospinal fluid/metrizamide aliquots recovered during the withdrawal procedure. There was a significant decrease in the number of seizures for withdrawal versus nonwithdrawal myelography (p < 0.01). The mean amount of metrizamide withdrawn per dog was 29% of the total injected.     

DOPPLER ULTRASOUND OF THE PROSTATE IN NORMAL DOGS AND IN DOGS WITH CHRONIC LYMPHOCYTIC-LYMPHOPLASMOCYTIC PROSTATITIS

The prostate gland of 11 normal dogs and five dogs with histological confirmed chronic lymphocytic or lymphoplasmocytic prostatitis were imaged with grey-scale and Doppler ultrasound. Three vessel types (prostatic artery, capsular artery and parenchymal artery) were identified with color Doppler and the resistive index and maximum and minimum velocities were measured with pulsed wave Doppler. No differences between normal dogs and dogs with prostatitis was identified in either grey-scale ultrasound or in any Doppler parameters measured. Regardless of histologic diagnosis, acepromazine (0.05 mg/kg IV) caused a significant decrease in capsular artery maximum and minimum velocities and prostatic artery resistive index. This study establishes normal Doppler ultrasound parameters for the intact male canine prostate gland. Additional studies are necessary to further evaluate the clinical utility of Doppler ultrasound in canine prostatic diseases.     

DOPPLER MEASUREMENT OF HEPATIC ARTERIAL FLOW IN DOGS: TECHNIQUE AND PRELIMINARY FINDINGS

The common hepatic artery in 10 healthy adult beagles, 20 healthy pups (13 Deerhounds and seven Irish Wolfhounds), and seven dogs with either a congenital or acquired hepatic disorder was examined by duplex-Doppler ultrasonography. Peak systolic velocity (Vs), resistive index (RI), pulse rate, angle of insonation, and sample volume depth were recorded. Measurements in Beagles were made after a 24 h fast and repeated 2 h after feeding. The mean Vs and RI in fasted Beagles were 1.5 m/s (range 1.1-2.3 m/s) and 0.68 (range 0.62-0.74), respectively. Postprandially, there were no significant differences in any of these variables. Mean Vs and RI were lower in pups: 1.0 m/s (range 0.8-1.3 m/s) and 0.59 (range 0.46-0.65), respectively (P < .001). Two dogs with congenital arterioportal fistula had higher mean Vs (P < .001) and lower mean RI (P < .05) than normal pups. No significant differences were detected between normal Beagles, three dogs with portal vein thrombosis, and two dogs with acquired hepatic insufficiency. Differences in measured hepatic blood flow in dogs of different age or breed will complicate diagnostic use of hepatic arterial Doppler measurements.     

THE EFFECTS OF AGE AND DIET ON THE ABSORPTION OF LEAD FROM THE GASTROINTESTINAL TRACT OF DOGS

SUMMARY Two groups of young growing dogs (one group maintained on balanced commercial diet and the other on high-fat-low-calcium diet) and one group of adult dogs on balanced commercial diet were given lead orally at 4 different dose levels. Post-treatment blood lead levels did not reveal any significant difference between the young and adult dogs maintained on balanced commercial diet. However, dogs on the high-fat-low-calcium diet showed marked elevation in blood lead at each of the 4 dose levels used. The results emphasise the importance of dietary factors in absorption of lead from the alimentary tract and suggest that the influence of age on lead uptake from the gut requires further evaluation.     

SONOGRAPHY OF THE MUSCULOSKELETAL SYSTEM IN DOGS AND CATS

Sonography of the musculoskeletal system in dogs and cats was undertaken to evaluate the application of this imaging procedure in orthopedics. In most of the patients a 7,5 MHz linear transducer was used because of its flat application surface and its resolving power. The evaluation of bone by sonography is limited, but sonography can provide addition information regarding the bone surface and surrounding soft tissue. Ultrasound is valuable for assessing joint disease. Joint effusion, thickening of the joint capsule and cartilage defects can be identified sonographically. It is also possible to detect bone destruction. Instabilities are often identified with the help of a dynamic examination. Soft tissue abnormalities of the musculoskeletal system lend themselves to sonographic evaluation. Partial or complete muscles or tendon tears are able to be differentiated and the healing process can be monitored. Most of the diseases that are in the area of the biceps or the achilles tendon, such as dislocation of the tendon, old injuries with scarification, free dissecates in the tendonsheath, tendinitis and/or tendosynovitis can be differentiated by sonography. In addition, with clinical and laboratory findings, it is often possible to make a correct diagnosis with ultrasound in patients with abscesses, foreign bodies, hematomas, soft tissue tumors and lipomas.     

PRELIMINARY OBSERVATIONS ON THE PRODUCTIVITY OF FEMALE CATTLE IN THE KIMBERLEY REGION OF NORTHWESTERN AUSTRALIA

Three experiments were done to determine the influence of supplementary feeding with crushed whole cotton seed and weaning on the productivity of breeding female cattle under range conditions in the Kimberley region, north-western Australia. In the first experiment, supplementary feeding cut losses of breeding cows from 47% to nil, and increased calf turn-off from 18% to 58%, in a sample of cattle from Argyle Downs cattle station during a severe dry season. In the second experiment, weaning calves at 4–6 months of age reduced weight loss in supplemented cows, from 21 to 8% over the last 100 days of the dry season, although the subsequent growth of supplemented weaned calves was inferior to that of non-weaned calves. In the third experiment, weaning of calves had no effect on body weight changes in supplemented cows, although non-weaned calves gained significantly faster than weaned supplemented calves. Control of cattle tick infestation by spraying increased blood haematocrit and haemoglobin values, but had no effect on total plasma proteins. A survey of feral cattle in the Kimberley area showed depressed blood haeboglobin, haematocrit and plasma protein values in breeding cows compared with other classes of cattle.     

莫能菌素对细粒棘球蚴原头蚴作用的试验

将细粒棘球蚴原头蚴培养于含7μg/ml莫能菌素的NCTC135培养液中,对其在36小时内的活动及结构变化作了观察。光镜下观察,培养至12小时部份虫体停止活动;至24小时已有半数虫体结构模糊,美蓝着染证明部分死亡;至36小时所有原头蚴结构模糊,全部死亡。电镜下观察,虫体高尔基复合体最先出现退行性变化,随后线粒体结构破坏,进而引起整个胞质及胞核的改变,至36小时细胞死亡。文中就莫能菌素作用的特点及细胞器改变的意义作了讨论。     

国产咪唑苯脲二丙酸盐在牛体内的药代动力学及组织残留

给牛单剂量肌注咪唑苯脲二丙酸盐(2mg/kg)。用紫外分光光度计测出不同时间的血药浓度,并按有吸收一室模型=M(e~(-ket)—e~(-kat))公式,计算出咪唑苯脲的主要药代动力学参数:吸收速率常数(k_a)为2.027h~(-1);清除速率常数(k_e)为0.419h~(-1),峰时间(T~(max))为1.18h;峰浓度(C~(max))为1.746μg/ml;吸收相半衰期(t1/2k_a)为0.342h,消除相半衰期(t1/2k_e)为1.165h;表观分布容积(Vd)为0.88L/kg;体清除率(BIC)为0.25L/kg/h。咪唑苯脲在牛的肝、肾、心,胆汁、脑、肌肉、脂肪中的残留量:停药后1个月分别为0.94、1.47、1.10、1.89,0.81、1.47和0.72μg/g;停药后2个月分别为0.763、0.454、0.232、0.493、0.106、0.662和0.441μg/g;停药后3个月分别为0.512、0.326、0.174、0.019、0.067、0.183和0.058μg/g。     

马实验性软组织伤冷冻效应观察

选择营养中等的成龄健康蒙古马10匹,分为两组,均实验性地造成体表软组织伤(长12cm,深3cm切口),分别立即及24h后进行冷冻。对冷冻诱起马体表局部软组织坏死及其修复特点,以及冷冻性免疫作用进行了系统观察。结果:①体表软组织冷冻性坏死的性质,最初属凝固性坏死,以后呈干性或湿性坏疽变化;②在冷冻性损伤修复过程中,损伤深部健康组织首先形成肉芽组织分界面,成为防止感染的屏障和修复损伤的肉芽组织基础;在坏死组织脱落后,伤面pH为7.0～7.7,有利于肉芽再生和防止化脓性感染;修复过程明显见有组织坏死及肉穿组织生成,属第二期愈合,但愈合后不留功能障碍;③冷冻性坏死能诱起T淋巴细胞显著增多(冷冻后第三周t=2.8068,P<0.05,第四周t=6.4869, P<0.01),可作为冷冻性免疫力增强的指标之一。