COMPARATIVE EFFICACY OF DIFFERENT ANTIDOTES AGAINST EXPERIMENTAL NITRATE INTOXICATION IN RABBITS

The antidotal efficacy of aqueous garlic extract, methylene blue, and velenium (Vitamin E + sodium selenite) was compared against experimental nitrate intoxication in rabbits. Forty-two, albino rabbits of identical age, gender, and body weight were randomly divided into 7 groups (A to G) and subjected to experimental treatments for a period of 40 days. Rabbits of group A were offered only normal feed and served as negative control, while, rabbits of group B constituted the positive control group and received feed supplemented with sodium nitrate at 400 mg/kg body weight. Sodium nitrate-containing feed and intraperitoneal injection of 1% methylene blue solution at 2 mg/kg body weight were administered to group C. Rabbits of group D were given sodium nitrate-supplemented feed and aqueous garlic extract at 500 mg/kg body weight through oral route. Group E was treated with sodium nitrate-added feed, intraperitoneal injection of 1% methylene blue solution at 2 mg/kg body weight, and oral administration of garlic extract at 500 mg/kg. Velenium (25 mg of Vitamin E + 2.2 mg of sodium selenite per ml) was intraperitoneally injected at 1 ml/kg body weight to rabbits of group F along with the provision of sodium nitrate-supplemented feed. In addition to being fed with sodium nitrate-containing feed, group G obtained intraperitoneal injection of velenium at 1 ml/kg body weight and oral administration of garlic extract at 500 mg/kg body weight. The efficacy of antidotes was assessed on the basis of changes in blood nitrite level, biochemical profile, and gross pathological lesions manifested by the treated rabbits. The combination of methylene blue and garlic extract was highly effective in treating nitrate toxicity followed by methylene blue, garlic extract, and velenium, respectively. Whereas, the concurrent administration of garlic extract and velenium was least efficacious in terms of antidotal efficacy. In conclusion, aqueous garlic extract can be effectively used either alone or in combination with methylene blue when treating rabbits diagnosed with nitrate toxicity.     

Successful therapy of balantidiosis of pigs with acetarsol and oxytetracycline

Severe clinical balabtidiosis in 2-month old piglets was treated with acetarsol alone and acetorsol in combination with oxytetracycline. Three groups of 15 animals each were used in this trial. Group 1 received acetarsol at a dose rate of 20 mg/kg body weight orally once daily for 4 days. Group 2 received acetarsol as group 1 plus oxytetracycline at a dose rate of 15 mg/kg body weight orally in feed concentrate twice daily for 4 days. Group 3 animals served as non-treated controls. As judged by clinical and parasitological examinations, acetarsol was found to be 85.7% effective and the combination of acetarsol and oxytetracycline 100% effective. No sign of intolerance or toxicity was observed.     

The effects of thiamin on lead metabolism: organ distribution of lead 203.

The effect of thiamin on the organ distribution of lead was evaluated in CD-1 mice exposed intragastrically or intraperitoneally to a single dose of lead acetate (100 micrograms) containing 100 microCi lead 203. They were treated with either thiamin (25 or 50 mg/kg body weight), calcium ethylenediaminetetraacetic acid (CaEDTA) (50 mg/kg body weight), or combinations of thiamin and CaEDTA. The whole body retention and the organ distribution of lead 203 varied depending upon the route of lead administration, dose of thiamin and the specific treatment combination. Thiamin (25 or 50 mg/kg) treatment increased the whole body retention of both intragastric and intraperitoneal lead by approximately 10% in each instance. Calcium ethylenediaminetetraacetic acid, either alone or in combination with thiamin (50 mg/kg) reduced the whole body retention of lead by as much as 14% regardless of route of lead exposure. The relative retention of lead by the liver, kidney and spleen was greater in mice exposed to lead by the intragastric route. Regardless of route, CaEDTA in the combined treatment reduced the relative retention of lead in both the liver and kidney, whereas thiamin alone only reduced the retention of lead in the kidney. The results of this study indicate that thiamin in combination with CaEDTA alters the distribution and retention of lead in a manner which may have therapeutic application as it relates to chelation therapy.     

Anthelmintic efficacy of febantel combined with praziquantel in dogs

Ninety-four dogs were randomly assigned to 1 of 6 groups (5 treated and 1 untreated control) for evaluation of anthelmintic efficacy. Three anthelmintic formulations were studied: a febantel paste, a praziquantel paste, and a combination paste containing both active ingredients. Treated dogs were dosed once daily for 3 days. The minimal effective dosages in combination were established as 10 mg of febantel and 1 mg of praziquantel/kg of body weight. At those dosages for the combination, 99.5% to 100% of the major nematodes and cestodes identified (ie, Ancylostoma caninum, Trichuris vulpis, Toxocara canis, Dipylidium caninum, and Taenia pisiformis) were eliminated. Febantel paste (10 mg/kg) alone was ineffective against cestodes (14.2% elimination of Dipylidium caninum) and praziquantel paste (1 mg/kg) alone was ineffective (0% to 2.4% elimination) against nematodes.     

Cocontamination of swine diets by aflatoxin and diacetoxyscirpenol

The effects of dietary aflatoxin (AF) and diacetoxyscirpenol (DAS), singly and in combination, were evaluated in growing crossbred barrows. The experimental design consisted of 4 treatments of 9 barrows each fed diets containing 1) 0 mg AF and 0 mg DAS/kg feed (control), 2) 2.5 mg AF/kg feed, 3) 2.0 mg DAS/kg feed, or 4) 2.5 mg AF + 2.0 mg DAS/kg feed for 28 days (10-14 weeks of age). Production performance, serum biochemical, hematologic, and pathologic measurements were made. Body weight and body weight gain were significantly decreased by each toxin but more so by the combination treatment. The effects were additive in nature. Liver and spleen weights, as percentages of body weight, were increased by the AF and AF + DAS treatments, and AF or AF + DAS treatments induced diffuse hepatocellular vacuolar change, early portal fibrosis, and early bile duct hyperplasia. Aflatoxin increased serum values of creatinine and gamma glutamyl transferase, cholinesterase, and alkaline phosphatase activities; increased packed cell volume and hemoglobin; and decreased urea nitrogen and total iron binding capacity. DAS reduced serum iron binding capacity. The AF + DAS treatment increased serum gamma glutamyl transferase and alkaline phosphatase activities, increased hemoglobin, and decreased serum iron binding capacity. Generally, the combination treatment could be described as additive or less than additive, with most of the effects attributable to AF. Under the conditions and parameters monitored in this study, AF and DAS had no synergistic toxic effects when incorporated into diets of growing barrows.     

Effects of treatment of growing swine with aflatoxin and T-2 toxin

Effects of dietary aflatoxin (AF) and T-2 toxin, singly and in combination, were evaluated in growing crossbred (Yorkshire x Landrace x Hampshire) pigs. The experimental design consisted of 4 treatment groups of 6 barrows each fed diets containing 0 mg of AF and T-2/kg of feed (controls; group 1), 2.5 mg of AF/kg of feed (group 2), 10 mg of T-2/kg of feed (group 3), or 2.5 mg of AF plus 10 mg of T-2/kg of feed (AF + T-2; group 4) ad libitum for 28 days (7 to 11 weeks of age). Production performance, and serum biochemical, and hematologic evaluations were made weekly. Body weight and body weight gain were depressed by all toxin treatments, but the effect of AF and T-2 toxin in combination was less than additive. Liver and kidney weights, as a percentage of body weight, were increased by AF treatment, and heart weight, as a percentage of body weight, was increased by T-2 treatment. Treatment with T-2 toxin induced necrotizing contact dermatitis on the snout, buccal commissures, and prepuce. Consumption of AF resulted in increased serum activities of alkaline phosphatase, aspartate transaminase, cholinesterase, and gamma-glutamyltransferase, and decreased serum concentrations of urea nitrogen, cholesterol, albumin, total protein, calcium, potassium, magnesium, and phosphorus. Consumption of T-2 toxin resulted in increased serum triglyceride concentration and decreased serum iron concentration. Treatment with AF induced lower serum unsaturated iron-binding capacity and high RBC count, PCV, hemoglobin concentration, WBC count, and prothrombin time.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of graded levels of aflatoxin, ochratoxin and their combinations on the performance and immune response of broilers

1. The effects of dietary aflatoxin (AF, 0.5, 1.0 and 2.0 mg/kg), ochratoxin (OA, 1.0, 2.0 and 4.0 mg/kg) or combinations of these on body weight gain, feed efficiency, organ weights and immune response were studied in broilers. 2. Significant growth depression, reduced food consumption and poor food conversion efficiency were recorded in broilers fed a diet containing the greater concentrations of AF (1 and 2 mg/kg) and OA (2 and 4 mg/kg). 3. The combination of 2 mg/kg AF and 4 mg/kg OA exerted the maximum adverse effect on growth, feed intake and feed efficiency, indicating a synergistic effect on performance. 4. AF at 2 mg/kg in the diet caused a significant increase in the relative weight of liver, whereas the relative weight of kidney was significantly increased at 4 mg/kg of OA. A significant decrease in the relative weight of the bursa of Fabricius was noted at the highest concentration of AF (2 mg/kg) and combinations of 1 and 2 mg/kg AF and 2 and 4 mg/kg OA. 5. Cell mediated immunity (CMI), in terms of mean skin thickness (MST) sensitive to dinitrochlorobenzene (DNCB), was significantly reduced in chicks given the combination of 2 mg/kg AF and 4 mg/kg OA. Haemagglutination (HA) titre against sheep red blood cells (SRBCs) peaked at 42 d of age. At 42 and 47 d of age, a significant decrease in HA titres was recorded in chicks given 4 mg/kg OA or a combination of AF (1 or 2 mg/kg) and OA (2 or 4 mg/kg). 6. AF at a dietary concentration of 1 mg/kg or more and OA at 2 mg/kg or more, either alone or in combination, caused severe reductions in growth and immune response.     

The toxicity of cyclopiazonic acid in weaned pigs

Five- to six-week-old crossbred pigs weighing 5 to 14 kg were given purified cyclopiazonic acid at dosages of 10, 1.0, 0.1, and 0.01 mg/kg body weight orally for 14 days. Clinical signs observed by day 7 in pigs given 10 mg/kg body weight were weakness, inactivity, anorexia, rough hair coats, and reduced body weights. These pigs also developed diarrhea during week 2 of the experiment. The pigs given 1.0 mg/kg body weight had rough hair coats and were moderately inactive during the second week of the experiment. At necropsy, lesions were observed only in pigs given 10 and 1.0 mg/kg body weight of cyclopiazonic acid. Lesions were gastric ulcers, mucosal hyperemia, and hemorrhage throughout the small and large intestine in pigs given 10 mg/kg body weight of cyclopiazonic acid. The pigs also had yellow, fibrononecrotic material in the lumen of the small intestine and pale livers. One pig given 1.0 mg/kg body weight had gastric ulceration. Microscopic lesions in pigs given 10 mg/kg body weight were necrotizing gastroenteritis, focal hepatocellular necrosis, hepatic peripheral lobular fatty change, and focal renal tubular nephrosis with focal suppurative tubulointerstitial nephritis. Pigs given 1.0 mg/kg body weight of cyclopiazonic acid had necrotizing gastritis and villous blunting in the jejunum and ileum.     

内毒素对山羊肝脏的病理损伤和654-2的保护效应

通过给山羊静注大肠杆菌内毒素（ＥＴ）诱导ＥＴ休克,探讨ＥＴ休克时山羊肝脏的病理损伤,并观察山莨菪碱（６５４－２）对其影响。结果表明,ＥＴ自理组在注射后５ｈ,肝脏表现出明显的病理变化,特征为实质细胞退行性变化,微血管淤血、有透明血栓形成,血管内有淋巴细胞和中性粒细胞粘聚,且肝脏有明显的超微结构变化。６５４－２能有效地缓解或减轻ＥＴ引起的毒性损伤。     

约氏乳杆菌对大鼠生长性能、血液指标及脏器指数的影响

本试验旨在研究约氏乳杆菌对大鼠生长性能、血液指标及脏器指数的影响。试验选取SD大鼠80只,雌雄各半。大鼠按照体重相近的原则随机分为4个剂量组,即阴性对照组、试验Ⅰ(5 000 mg/kg体重)、试验Ⅱ(1 000 mg/kg体重)和试验Ⅲ组(200 mg/kg体重)。试验期为30 d。结果表明:试验剂量为200~1 000 mg/kg体重时,约氏乳杆菌对大鼠体增重、总采食量、饲料转化率、血液学指标和病理学指标的影响无显著性差异(P>0.05);试验剂量为5 000 mg/kg体重时,谷草转氨酶、血糖、总胆固醇差异不显著(P>0.05);与其他剂量组相比,大鼠的体增重和总采食量显著降低(P<0.05),但饲料转化率无显著差异(P>0.05);谷丙转氨酶水平显著降低(P<0.05),白蛋白和总蛋白显著增高(P<0.05);雌性大鼠尿素氮和雄性大鼠肌酐显著增高(P<0.05)。综合分析,约氏乳杆菌剂量低于1 000 mg/kg体重时,对大鼠平均日增重、血液指标及脏器指数无影响;约氏乳杆菌剂量高于5 000 mg/kg体重时,对大鼠脏器指数有影响。     

Serum and synovial fluid steady-state concentrations of trimethoprim and sulfadiazine in horses with experimentally induced infectious arthritis

The tarsocrural joints of 11 horses were inoculated with 1.2 to 2.16 x 10(6) viable Staphylococcus aureus organisms susceptible to a trimethoprim-sulfadiazine (TMP-SDZ) combination with minimal inhibitory concentration (MIC) of 0.25 micrograms of TMP/ml and 4.75 micrograms of SDZ/ml. Antimicrobial treatment consisted of oral administration of a TMP-SDZ combination--30 mg/kg of body weight given once daily (group-1 horses) or 60 mg/kg given as 30 mg/kg every 12 hours (group-2 horses). Paired serum and synovial fluid samples were obtained before intra-articular inoculation with the S aureus, after inoculation with S aureus but before antimicrobial treatment, and after inoculation at various hourly intervals after oral administration of the TMP-SDZ combination. The TMP-SDZ combination was administered daily in the 2 dosages for 21 days. Samples were collected after day 3 of repetitive drug administration so that drug steady-state concentration would have been achieved. Serum and synovial fluid samples were analyzed for TMP and SDZ concentrations. Administration of the TMP-SDZ combination at a dosage of 30 mg/kg once daily was not effective in maintaining TMP or SDZ concentrations above the MIC of TMP-SDZ for the S aureus (0.25 and 4.75 micrograms/ml for TMP and SDZ, respectively) in the infected synovial fluid or in maintaining adequate TMP concentration in the serum. The alternative use of the TMP-SDZ combination at a dosage of 60 mg/kg given as 30 mg/kg every 12 hours was effective in maintaining serum and synovial fluid concentrations of TMP and SDZ that were greater than the MIC for the infective organism.(ABSTRACT TRUNCATED AT 250 WORDS)     

Anesthesia in the Richardson's ground squirrel: comparison of ketamine, ketamine and xylazine, droperidol and fentanyl, and sodium pentobarbital

A combination of ketamine and xylazine (88.9 mg of ketamine/ml and 11.1 mg of xylazine/ml) given IM (85.5 +/- 3.4 mg of ketamine/kg of body weight and 10.6 +/- 0.5 mg of xylazine/kg) or subcutaneously (85.6 +/- 4.0 mg of ketamine/kg and 10.7 +/- 0.7 mg of xylazine/kg) induced effective surgical anesthesia for 20 to 30 minutes in Richardson's ground squirrels. Use of ketamine alone (86 +/- 7 mg/kg, IM), a droperidol and fentanyl combination (2.6 +/- 0.4 mg of droperidol/kg and 52 +/- 8 micrograms of fentanyl/kg, IM), or sodium pentobarbital (50 +/- 2 mg/kg, intraperitoneally) did not induce surgical anesthesia, but did induce depressed respiratory rates in the squirrels.     

半胱胺对育成期银狐生长性能的影响

为研究半胱胺对育成期银狐生长性能的影响，选用2月龄左右、健康银黑狐仔狐224只（公母各半）。其中公狐体重在2.50 kg左右（P＞0.05），母狐体重在2.10 kg左右（P＞0.05）。随机分200只（公母各半）为试验组，剩余24只（公母各半）为对照组。饲养试验持续时间大约为3个月（2004年6月10日~8月31日）。采用复因子试验设计中的析因试验设计，为二因子有重复的试验设计。在5个不同半胱胺添加时间间隔（1、3、5、7和9 d）中分别添加5个不同数量的半胱胺（每千克体重添加10、40、70、100和130 mg）。对照组分为12个重复，每个重复2只（公母各半）。试验测定了银狐的采食量、饲料转化率及体增重。结果表明，在25个组合中只有每间隔5 d按70 mg/ kg体重浓度添加1次半胱胺组可使银狐体增重及饲料转化率达到最高,分别比对照组提高15.08%（P＜0.05）和20.21%（P＜0.01）。整个试验组银狐采食量都低于对照组, 其中70 mg/kg体重5 d组采食量比对照组降低4.52%( P＜0.05）。     

半胱胺对育成期银狐生长性能的影响

为研究半胱胺对育成期银狐生长性能的影响,选用2月龄左右、健康银黑狐仔狐224只（公母各半）。其中公狐体重在2.50 kg左右（P＞0.05）,母狐体重在2.10 kg左右（P＞0.05）。随机分200只（公母各半）为试验组,剩余24只（公母各半）为对照组。饲养试验持续时间大约为3个月（从2004年6月10日~8月31日）。采用复因子试验设计中的析因试验设计,为二因子有重复的试验设计。在5个不同半胱胺添加时间间隔（1、3、5、7和9 d）中分别添加5个不同数量的半胱胺（每千克体重添加10、40、70、100和130 mg）。对照组分为12个重复,每个重复2只（公母各半）。试验测定了银狐的采食量、饲料转化率及体增重。结果表明,在25个组合中只有每间隔5 d按70 mg/ kg体重浓度添加1次半胱胺组可使银狐体增重及饲料转化率达到最高,分别比对照组提高15.08%（P＜0.05）和20.21%（P＜0.01）。整个试验组银狐采食量都低于对照组, 其中70 mg/kg体重5 d组采食量比对照组降低4.52%( P＜0.05）。     

Sloth bear immobilization with a ketamine-xylazine combination: reversal with yohimbine

Five captive sloth bears (Melursus ursinus) were immobilized with a combination of ketamine (5.80 to 9.75 mg/kg of body weight) and xylazine (1.40 to 2.44 mg/kg), given IM. The youngest bear was immobilized twice, 62 days apart; all other bears were immobilized only once. Induction times were 4 to 25 minutes. After completion of various intended procedures, yohimbine (0.125 mg/kg) was administered IV. Arousal times were 2 to 20 minutes and bears were standing in 17 to 51 minutes. Compared with reported recovery times of 2 to 3 hours for bears immobilized with ketamine-xylazine combinations but not given an antagonist, results of the present study indicated that yohimbine reduces anesthesia recovery times in sloth bears immobilized with ketamine-xylazine combination.     

Xylazine-ketamine-induced anesthesia in rats and its antagonism by yohimbine

A combination of xylazine and ketamine was used to anesthetize 60 male rats, and then yohimbine was given to evaluate its reversing effect on xylazine-ketamine-induced anesthesia. In experiment A, xylazine (21 mg/kg of body weight) and ketamine (45 mg/kg) were admixed and administered IM to 12 Sprague-Dawley rats. Anesthesia lasted approximately 70 minutes. The xylazine-ketamine combination also induced polyuria, bradycardia, and bradypnea. When yohimbine (2.1 mg/kg) was given intraperitoneally 20 minutes after the xylazine-ketamine injection, the rats regained consciousness and righting reflexes within approximately 10 minutes. Yohimbine also reversed the bradycardia and bradypnea and appeared to reduce the polyuria induced by the xylazine-ketamine combination. In experiment B, xylazine (15.4 mg/kg) and ketamine (33 mg/kg) were admixed and given IM to 48 Holtzman rats. The combination induced surgical anesthesia for at least 30 minutes, during which a surgical procedure involving grafting a section of the sciatic nerve into the hypothalamus was performed. In rats in which yohimbine (1 mg/kg) was given intraperitoneally 45 to 60 minutes after xylazine-ketamine administration (before natural recovery from the anesthesia), the righting reflex was apparent in less than 10 minutes.     

Effects of aflatoxin B1 and fumonisin B1 on body weight, antibody titres and histology of broiler chicks

1. Our objective was to evaluate the toxic effects of aflatoxin B1 (AFB1) and fumonisin B1 (FB1), administered singly or in combination to broilers. 2. Feeds were prepared with concentrations equal to 0, 50 and 200 microg AFB1/kg, and/or 0, 50 and 200 mg FB1/kg, and offered to broiler chicks from 8 to 41 d of age. The experimental design was totally randomised, in a 3 x 3 factorial arrangement with 9 treatments and 12 birds per treatment. Animals were vaccinated against Newcastle disease on d 14 of life and killed at 41 d. 3. Compared with controls, all mycotoxin-treated groups at 41 d had lower body weight and weight gain, and higher relative heart weight. The relative weight of the liver increased only in birds fed diets containing 200 mg FB1, singly or in combination with AFB1. 4. At 35 d, all groups receiving mycotoxin-treated rations had reduced geometrical mean antibody titres, with birds from groups fed combinations of AFB1 and FB1/kg having even lower values, when compared to the other groups. 5. Histological changes were observed only in liver from birds fed mycotoxin-contaminated rations, and in kidneys of birds fed the diet containing 200 microg AFB1 and 200 mg FB1/kg. Main alterations included vacuolar degeneration and cell proliferation of bile ducts in the liver, and hydropic degeneration in renal tubules in the kidneys. 6. We concluded that AFB1 and FB1 in combination have primarily additive effects on body weight, liver structure and immunological response of broilers at the concentrations used.     

Evaluation of diets contaminated with aflatoxin and ochratoxin fed to growing pigs

The effects of dietary aflatoxin and ochratoxin, fed singly and in combination, were evaluated in growing crossbred pigs. Five barrows (7 weeks old at beginning of study) per group were fed either control feed, 2.0 mg of aflatoxin (AF)/kg of feed, 2.0 mg of ochratoxin (OA/kg of feed, or 2.0 mg of AF and 2.0 mg of OA/kg of feed for 28 days. Production performance, serum biochemical, hematologic, and pathologic evaluations were made. Body weights were reduced by the combination treatment, whereas body weight gain was decreased by all toxin treatments. The effect of AF and OA in combination on body weight gain was additive. Liver weights were increased by the combination treatment, whereas kidney weights were increased only in the OA group. Aflatoxin caused decreases in serum calcium, sodium, phosphorus, urea nitrogen, cholesterol, and glucose concentrations, whereas OA alone caused decreases in serum phosphorus, cholesterol, and hematologic values. The AF-OA treatment induced decreases in mean corpuscular volume, packed cell volume, and in serum concentrations of phosphorus, cholesterol, and urea nitrogen. The AF-OA treatment increased serum alkaline phosphatase activities and triglycerides. It was concluded that AF and OA, singly or in combination, can affect clinical performance, serum biochemical and hematologic values, and organ weights of barrows. Although values of some measurements were affected more by the combination than by either toxin alone and suggested synergism or antagonism, the toxic interactions could best be described as additive.     

Comparison of Intra-articular and Epidural Morphine for Analgesia Following Stifle Arthrotomy in Dogs

We prospectively studied 18 dogs that presented for exploratory stifle arthrotomy, with or without meniscectomy, and lateral extracapsular stabilization as a result of cranial cruciate ligament rupture. Dogs were premedicated with acepromazine, induced with thiopental, and maintained with halothane in oxygen. Preoperatively, dogs were assigned to one of three groups. Group 1 (n = 6) received intra-articular morphine (0.1 mg/kg diluted in 1 mL/10 kg body weight of saline) and epidural saline (1 mL/5 kg body weight saline plus the volume of saline representing 0.1 mg/kg of morphine). Group 2 (n = 6) received intra-articular saline (1 mL/10 kg body weight of saline plus the volume of saline representing 0.1 mg/kg of morphine) and epidural saline (1 mL/5 kg body weight saline plus the volume of saline representing 0.1 mg/kg of morphine). Group 3 (n = 6) received intra-articular saline (1 mL/10 kg body weight of saline plus the volume of saline representing 0.1 mg/kg of morphine) and epidural morphine (0.1 mg/kg of morphine diluted in 1 mL/5 kg body weight saline). The efficacy of each analgesia regimen was evaluated for 6 hours postoperatively with a pain score based on subjective and objective variables. Serum Cortisol and blood glucose concentrations were measured. Butorphanol was used to provide analgesia as needed based on a predetermined maximum pain score. Supplemental analgesics were required postoperatively every 2 to 3 hours for 6 hours in all dogs that did not initially receive analgesics (group 2). Pain scores were significantly lower in dogs administered morphine intra-articularly (group 1) and epidurally (group 3) at 30 minutes and 30, 120, and 360 minutes, respectively, compared with dogs that did not initially receive analgesics (group 2). One dog in group 1 and one dog in group 3 required supplemental analgesia with butorphanol. There was no difference between analgesia produced by intra-articular morphine compared with that of epidural morphine. Side effects after intra-articular or epidural morphine were not observed. Intra-articular administration of morphine can produce effective analgesia in dogs comparable with that produced by epidural administration of morphine.     

Diphenylamine-induced renal papillary necrosis and necrosis of the pars recta in laboratory rodents

The nephrotoxicity of diphenylamine, the parent compound of the mefenamate family of nonsteroidal anti-inflammatory drugs, was evaluated in male Syrian hamsters, male Sprague-Dawley rats, and male Mongolian gerbils. Total renal papillary necrosis was observed in four of ten, seven of ten, and six of ten male Syrian hamsters orally treated with diphenylamine at respective doses of 400 mg/kg body weight/day, 600 mg/kg body weight/day, and 800 mg/kg body weight/day. Total renal papillary necrosis was also observed in five of ten and four of ten male Syrian hamsters intraperitoneally treated with diphenylamine at respective doses of 600 mg/kg body weight/day and 800 mg/kg body weight/day. Focal intermediate renal papillary necrosis was induced in two hamsters orally given diphenylamine at 600 mg/kg body weight/day and in two of ten hamsters intraperitoneally given diphenylamine at 800 mg/kg body weight/day. Apex-limited necrosis of the medullary interstitial cells and vasa recta and degeneration of the renal interstitial matrix occurred in two Sprague-Dawley rats orally administered diphenylamine at 800 mg/kg body weight/day. Degeneration and necrosis of the pars recta was induced in seven of ten hamsters intraperitoneally given diphenylamine at 400 mg/kg body weight/day. Gross and microscopic renal lesions were not observed in any Mongolian gerbils. It was concluded that the Syrian hamster is more susceptible to the papillotoxic effects of diphenylamine than the Sprague-Dawley rat and the Mongolian gerbil. Renal papillary necrosis in the Syrian hamster treated orally with diphenylamine is reproducible, is of short onset, and is induced in a high proportion of the hamsters (70-90%).(ABSTRACT TRUNCATED AT 250 WORDS)