Reduced efficacy of ivermectin, abamectin and moxidectin against field isolates of Haemonchus contortus     

Wooster MJ  Woodgate RG  Chick BF 《Australian veterinary journal》2001,79(12):840-842

OBJECTIVES: To investigate the reduced efficacy of ivermectin, abamectin and moxidectin against two field isolates of Haemonchus contortus. These isolates were identified on separate properties in the New England region of New South Wales. PROCEDURE: Reduced efficacy of macrocyclic lactone anthelmintics against two field isolates of H contortus was suspected. These isolates were obtained from sheep on separate farms and pen trials were performed to investigate the efficacy of macrocyclic lactones. The percentage efficacy was calculated for moxidectin, ivermectin and closantel against the isolate from one farm (VHR23) and for moxidectin, ivermectin and abamectin against the isolate from the second (VHR29). The persistent activity of moxidectin against both isolates was investigated. RESULTS: Ivermectin and closantel were found to have efficacies below 80% against established populations of VHR23. Moxidectin was effective against an established population of VHR23 but the persistent activity was reduced to 7 days. Moxidectin was also found to be effective against established populations of VHR29, however, ivermectin and abamectin were found to have efficacies below 80%. There was no evidence of persistent activity of moxidectin against VHR29. CONCLUSION: A reduction in efficacy of abamectin and/or ivermectin against field isolates of H. contortus was identified from two farms in the New England region of New South Wales. The persistent effect of moxidectin was reduced against both isolates.  相似文献   

Use of pneumocystoplasty for overinflation of the swim bladder in a goldfish     

Britt T  Weisse C  Weber ES  Matzkin Z  Klide A 《Journal of the American Veterinary Medical Association》2002,221(5):690-3, 645

A Ryukin goldfish was evaluated because of a 6-month history of progressive abdominal distention and positive buoyancy. Overinflation of the swim bladder was diagnosed, and the fish was anesthetized with tricaine methanesulfonate. Archimedes' principle was used to determine the volume of swim bladder that was removed surgically. The caudal swim bladder was exteriorized through an abdominal incision and 2 surgical clips were placed across it to limit its size. After surgery, the fish remained in a state of negative buoyancy in sternal and lateral recumbency on the bottom of the tank. Sutures were removed 15 days after surgery, but the fish died 24 days after surgery. A full necropsy could not be performed because of autolysis of the tissues, but the surgical clips and the swim bladder appeared unremarkable. Pneumocystoplasty may be a viable treatment for this condition.  相似文献   

Comparative efficacy of crystalline and amorphous oxfendazole in sheep     

MJ CARRIGAN  P PILE  BF CHICK 《Australian veterinary journal》1990,67(5):195-196

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Recurrence rates and sites for grade II canine cutaneous mast cell tumors following complete surgical excision.     

Chick Weisse  Frances S Shofer  Karin Sorenmo 《Journal of the American Animal Hospital Association》2002,38(1):71-73

A retrospective study was performed on 31 dogs with completely excised, grade II, cutaneous mast cell tumors in order to determine recurrence rates and sites. Distant tumor recurrence developed in 22% of dogs, and local tumor recurrence developed in 11% of dogs; however, the vast majority of these animals were incompletely staged initially. Complete surgical excision of grade II mast cell tumors was associated with effective local control in 89% of these dogs. Therefore, adjuvant radiation therapy might not be indicated in the majority of dogs with complete surgical excision.  相似文献   

Mitotic division in pancreatic beta cells   总被引：3，自引：0，他引：3  

A A Like  W L Chick 《Science (New York, N.Y.)》1969,163(870):941-943

Successful expansion of the islet cell mass occurs in genetically diabetic mice (C57 Bl/Ks-dbdb) following a period of dietary restriction, in the absence of a population of precursor cells. Differentiated cells that synthesize insulin retain the capability of undergoing mitotic division.  相似文献   

Biohybrid artificial pancreas: long-term implantation studies in diabetic, pancreatectomized dogs   总被引：5，自引：0，他引：5  

S J Sullivan  T Maki  K M Borland  M D Mahoney  B A Solomon  T E Muller  A P Monaco  W L Chick 《Science (New York, N.Y.)》1991,252(5006):718-721

Diabetic complications such as neuropathy, retinopathy, and renal and cardiovascular disease continue to pose major health risks for diabetic patients. Consequently, much effort has focused on approaches that could replace conventional insulin therapy and provide more precise regulation of blood glucose levels. The biohybrid perfused artificial pancreas was designed to incorporate islet tissue and a selectively permeable membrane that isolates this tissue from the immune system of the recipient. Biohybrid pancreas devices containing canine islet allografts were implanted in ten pancreatectomized dogs requiring 18 to 32 units of injected insulin daily. These implants resulted in good control of fasting glucose levels in six of these animals without further exogenous insulin for periods of up to 5 months.  相似文献   

The potential for grass-fed livestock: resource constraints     

Pimentel D  Oltenacu PA  Nesheim MC  Krummel J  Allen MS  Chick S 《Science (New York, N.Y.)》1980,207(4433):843-848

Using pasture and grazed forest-range for a system of producing live-stock by feeding grass alone reduces the inputs of energy about 60 percent and land resources about 8 percent, but also reduces by about half the production of animal protein in the United States. Under a system in which only grass was fed, livestock would be restricted to beef, milk, and lamb production. The amount of grain fed to U.S. livestock is about 135 million tons (metric) or about ten times the amount consumed by the U.S. population.  相似文献   

Use of a percutaneous atrial septal occluder device for complete acute occlusion of an intrahepatic portosystemic shunt in a dog     

Weisse C  Mondschein JI  Itkin M  Iyoob C  Solomon JA 《Journal of the American Veterinary Medical Association》2005,227(2):249-52, 236

A 3-month-old sexually intact male German Shepherd Dog was evaluated because of signs of depression, ataxia, and collapse. Clinicopathologic abnormalities included low serum BUN and albumin concentrations and high serum liver enzyme activities and plasma ammonia and serum bile acids concentrations. Abdominal ultrasonography revealed an intrahepatic portosystemic shunt (PSS). The dog was anesthetized; via a transjugular approach, guidewires and catheters were directed with fluoroscopic guidance to locate the shunt and determine its anatomic features. Minimal changes in portal vein pressure during temporary shunt balloon occlusion enabled complete shunt attenuation, which was performed by use of a self-expanding septal occlusion device that is typically used for treatment of atrial septal defects in humans. Following initial misplacement of the device, the procedure was repeated successfully 2 months later and resulted in complete shunt occlusion. One year after this second procedure, the dog was clinically normal and serum bile acids concentration was within reference limits. In certain dogs with intrahepatic PSSs, treatment with minimally invasive interventional techniques involving fluoroscopy may reduce the morbidity and mortality rates associated with more invasive surgical procedures.  相似文献   

Spontaneous resolution of iatrogenic chylothorax in a cat   总被引：1，自引：0，他引：1  

Greenberg MJ  Weisse CW 《Journal of the American Veterinary Medical Association》2005,226(10):1667-70, 1659

Chylothorax is an uncommon condition of dogs and cats defined by the accumulation of chylous effusion within the pleural space. Chylothorax has been experimentally created in dogs and cats by ligation of the cranial vena cava and has been reported to occur spontaneously in dogs with naturally occurring obstruction of the cranial vena cava. In the cat of this report, iatrogenic chylothorax was caused by surgical ligation and transection of the left brachiocephalic vein during a tracheal resection and anastomosis procedure. The chylous effusion resolved with medical management 9 weeks after surgery.  相似文献   

Survival times in dogs with right atrial hemangiosarcoma treated by means of surgical resection with or without adjuvant chemotherapy: 23 cases (1986-2000)     

Weisse C  Soares N  Beal MW  Steffey MA  Drobatz KJ  Henry CJ 《Journal of the American Veterinary Medical Association》2005,226(4):575-579

OBJECTIVE: To determine survival times in dogs with right atrial hemangiosarcoma treated by means of pericardectomy and tumor resection, with or without adjuvant chemotherapy, and identify complications associated with treatment. DESIGN: Retrospective study. ANIMALS: 23 dogs. PROCEDURE: Dogs were included only if the diagnosis was confirmed histologically. RESULTS: The most common initial complaints included acute collapse (8 [35%] dogs), anorexia or inappetence (8 [35%]), and lethargy (8 [35%]). The most common physical examination abnormalities included muffled heart sounds (12 [52%] dogs), tachycardia (7 [30%]), and weak pulses (7 [30%]). Postoperative complications developed in 12 (52%) dogs; however, most complications were minor. Twenty (87%) dogs were discharged from the hospital. Survival time was significantly longer in the 8 dogs that received adjuvant chemotherapy (mean, 164 days; median, 175 days) than in the 15 dogs that did not receive chemotherapy (mean, 46 days; median, 42 days). Dogs that received chemotherapy were significantly younger and had significantly lower WBC counts than did dogs that did not receive chemotherapy. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that in dogs with right atrial hemangiosarcoma, surgical resection of the tumor was associated with a low complication rate and complications that did arise typically were minor. In addition, use of adjuvant chemotherapy following resection was associated with significantly longer survival times, compared with resection alone.  相似文献