沙咪珠利预防鸡球虫病的药效试验研究

为了解一种新型三嗪类抗球虫化合物沙咪珠利在临床预防鸡球虫病的合理使用剂量和对鸡球虫病常见4种病原的有效性和敏感性,采用抗鸡球虫笼养试验模型和抗球虫活性指数、盲肠病变计分、相对卵囊产量、增重等指标评价沙咪珠利的药效。结果显示,沙咪珠利饲料中添加9 mg/kg以上时,对柔嫩艾美耳球虫的抗球虫活性稳定在高效水平,以10 mg/kg作为临床使用推荐剂量是相对安全和合理的。沙咪珠利饲料中添加10 mg/kg,预防鸡柔嫩艾美耳球虫(Eimeria tenella),毒害艾美耳球虫(Eimeria necatrix)、堆型艾美耳球虫(Eimeria acervulina)和巨型艾美耳球虫(Eimeria maxima)引起的球虫病的抗球虫指数分别为197、188、194和190,抗球虫活性达高效水平,沙咪珠利具有预防4种常见致病虫株引发的球虫病的疗效,其作用机理等有待进一步的研究。     

抗鸡球虫病的三嗪类新化合物纳川珠利的药效试验

采用抗鸡柔嫩艾美尔球虫实验室笼养试验模型,对新合成的三嗪化合物纳川珠利进行了2批次的抗球虫活性试验。结果显示,纳川珠利添加剂量5、10和30 mg/kg时,抗球虫指数均大于180。添加剂量1和3 mg/kg时,见有少量血便和盲肠病变,抗球虫活性介于中效和高效之间。表明纳川珠利是一种高效安全的新型三嗪类抗球虫化合物,推荐使用剂量以3~5 mg/kg为宜,有望开发成为一种新的抗球虫药物。     

二硫代碳酸香芹酚酯对人工诱发鸡球虫病的疗效实验

为了评价二硫代碳酸香芹酚酯的抗球虫效果,将其按100、150、200mg/kg浓度添加于饲料中治疗人工感染鸡柔嫩艾美耳球虫病,设妥曲珠利25mg/kg、地克珠利2mg/kg浓度拌料给药作对照。结果显示,二硫代碳酸香芹酚酯高、中两种剂量治疗鸡球虫病具有良好的效果,抗球虫指数均在160以上,与妥曲珠利的效果相当,属于中效抗球虫药。临床推荐150mg/kg拌料给药,连用7d。     

通扬球虫清对鸡球虫病的疗效试验

测定了通扬球虫清对鸡球虫病的疗效,三批试验结果显示,通扬球虫清高剂量组(甲基三嗪酮37.5mg/L饮水浓度,8天)和中剂量1组(甲基三嗪酮25mg/L饮水浓度,8天)的抗球虫指数始终在高效水平;中剂量2组(甲基三嗪酮25mg/L饮水浓度,2天)和通扬独霸组(地克珠利0.5mg/L饮水浓度,8天)的抗球虫指数相近,也属高效抗球虫范围;通扬球虫清低剂量组(甲基三嗪酮12.5mg/L饮水浓度,8天)的抗球虫指数属中等有效水平。综合各项指标及与通扬独霸组的药效相比,通扬球虫清在临床上选用25mg/L饮水浓度,连续饮用2天或2天以上切实可行。     

亚麻油日粮对地克珠利抗球虫效力的影响

研究采取单因子试验设计法。人工感染柔嫩艾美耳球虫6×104/鸡,分别在4%亚麻油日粮中添加0mg/kg、0.6mg/kg和0.8mg/kg抗球虫新药地克珠利,以抗球虫新药地克珠利的推荐量1mg/kg为对照。结果获得:在日粮中添加4%亚麻油后,可减少地克珠利的使用量。抗球虫指数对照组为190,4%亚麻油+0.6mg/kg组为199,4%亚麻油+0.8mg/kg为197。亚麻油对地克珠利抗球虫效力有增效作用。     

纳川珠利对鸡柔嫩艾美耳球虫病的防治效果研究

以存活率、相对增重率、血便计分、病变值、卵囊值和抗球虫活性指数(Anticoccidial index,ACI)为药效评判指数,考察了新三嗪类化合物纳川珠利对人工感染的鸡柔嫩艾美耳球虫病的预防和治疗效果.结果显示,纳川珠利对鸡柔嫩艾美耳球虫病有良好的防治效果,ACI值均属高效范围,有望开发为新的抗球虫药物.     

几种药物的联合使用对堆型艾美耳球虫的疗效及耐药性试验

目的研究几种药物的联合抗球虫效果及其耐药性。方法将175只14日龄罗曼粉雏公鸡随机分为7组,设5个试验组,按组分别投予磺胺氯吡嗪300 mg/kg 氨吡啉125 mg/kg,磺胺氯吡嗪300 mg/kg 尼卡巴嗪125mg/kg,磺胺氯丙嗪300 mg/kg 左旋咪唑10 mg/kg,地克珠利3 mg/kg,地克珠利2 mg/kg 氨丙啉125 mg/kg,并设立感染不用药和不感染不用药对照组。给药后2 d,除不感染不用药对照组的鸡只外,其余全部试验鸡每只分别接种E.acervulina孢子化卵襄8×104个。以抗球虫指数(ACI)作为判定药物效力的指标;并根据最适抗球虫活性百分率(POAA)病变记分减少率(RLS)、相对卵囊产量(ROP)、三项指标综合判定球虫对上述抗球虫药的耐药性。结果地克珠利与氨丙啉的联合使用,其抗球虫指数达181.25,其余各组药的抗球虫指数均在165~170之间;且该球虫株对磺胺氯吡嗪 尼卡巴嗪、磺胺氯吡嗪 左旋咪唑、地克珠利组药物有轻度耐药性(-- ),对磺胺氯吡嗪 氨丙啉有中度耐药性(- )。结论地克珠利与氨丙啉联合使用对E.acervulina具有高效抗球虫作用。     

纳川珠利溶液剂对鸡球虫病的药效学研究

对两种不同配方的0.3%纳川珠利溶液剂,分别以6、3、1mg/L三种剂量饮水预防人工感染的鸡柔嫩艾美耳球虫,并用地克珠利预混剂以1mg/kg剂量作为对照。结果显示,0.3%纳川珠利溶液剂的两种配方以上述3种剂量饮水预防鸡球虫病,具有良好的抗球虫效果,抗球虫指数在180以上,属高效范围。表明0.3%纳川珠利溶液剂是纳川珠利的一种高效预防鸡球虫病的良好剂型。     

驱球止痢合剂防治耐药柔嫩艾美尔球虫的效果研究

目的:研究驱球止痢合剂对耐药柔嫩艾美尔球虫的防治效果。方法:通过对鸡只人工攻毒具有耐药性的柔嫩艾美尔球虫感染试验,建立鸡球虫病模型,再经过用药治疗试验后,计算出各组的抗球虫指数(ACI)。结果:驱球止痢合剂组的抗球虫指数(ACI)最高。结论:结果表明,驱球止痢合剂相较于地克珠利对防治耐药鸡柔嫩艾美尔球虫具有更好的效果。     

地克珠利混悬液对鸡球虫病的疗效观察

对20 g/L地克珠利混悬液,以4、2、1 mg/kg 3种浓度饮水预防鸡艾美耳球虫人工感染,并用地克珠利溶液以2 mg/kg浓度饮水作对照.结果表明,20 g/L地克珠利混悬液以4、2、1 mg/kg 3种浓度饮水预防鸡球虫病,具有良好的效果,抗球虫指数均在180以上,效果优于地克珠利溶液以2 mg/kg饮水.田间试验有效率81.8%,治愈率71%,证实20 g/L地克珠利混悬液是地克珠利又一种高效预防鸡球虫病新剂型.     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein