Evaluation of prevalence and clinical implications of anthelmintic resistance in gastrointestinal nematodes in goats

OBJECTIVE: To determine prevalence of resistance to all anthelmintics that are commonly used to treat gastrointestinal nematodes (GINs) in goats. DESIGN: Prospective study. ANIMALS: 777 goats. PROCEDURE: On each farm, goats were assigned to 1 of 5 treatment groups: untreated controls, albendazole (20 mg/kg [9.0 mg/lb], p.o., once), ivermectin (0.4 mg/kg [0.18 mg/lb], p.o., once), levamisole (12 mg/kg [5.4 mg/lb], p.o., once), or moxidectin (0.4 mg/kg, p.o., once), except on 3 farms where albendazole was omitted. Fecal samples were collected 2 weeks after treatment for determination of fecal egg counts (FECs), and percentage reductions were calculated by comparing data from anthelmintic-treated and control groups. Nematode populations were categorized as susceptible, suspected resistant, or resistant by use of guidelines published by the World Association for the Advancement of Veterinary Parasitology. RESULTS: Resistance to albendazole was found on 14 of 15 farms, and resistance to ivermectin, levamisole, and moxidectin was found on 17, 6, and 1 of 18 farms, respectively. Suspected resistance to levamisole and moxidectin was found on 4 and 3 farms, respectively. Resistance to multiple anthelmintics (albendazole and ivermectin) was found on 14 of 15 farms and to albendazole, ivermectin, and levamisole on 5 of 15 farms. Mean overall FEC reduction percentages for albendazole, ivermectin, levamisole, and moxidectin were 67, 54, 94, and 99%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Anthelmintic resistance in GINs of goats is highly prevalent in the southern United States. The high prevalence of resistance to multiple anthelmintics emphasizes the need for reexamination of nematode control practices.     

Cardiac‐gated,phase contrast magnetic resonance angiography is a reliable and reproducible technique for quantifying blood flow in canine major cranial abdominal vessels

Blood flow changes in cranial abdominal vessels are important contributing factors for canine hepatic disease. This prospective, experimental, pilot study aimed to evaluate cardiac‐gated, phase contrast magnetic resonance angiography (PCMRA) as a method for characterizing blood flow in canine major cranial abdominal vessels. Eleven, healthy, adult beagle dogs were sampled. Cardiac‐gated, phase contrast magnetic resonance angiography of the cranial abdomen was performed in each dog and blood flow was independently measured in each of the major cranial abdominal vessels by three observers, with two observers recording blood flow values once and one observer recording blood flow values three times. Each dog then underwent ultrasonographic examination of the liver with fine needle aspirations and biopsies submitted to cytologic and histologic examination. The mean absolute stroke volume and velocity were respectively 9.6 ± 1.9 ml and –11.1 ± 1.1 cm/s for the cranial abdominal aorta, 2.1 ± 0.6 ml and –6.6 ± 1.9 cm/s for the celiac artery, and 2.3 ± 1.0 ml and –7.9 ± 3.1 cm/s for the cranial mesenteric artery. The mean absolute stroke volume and velocity were respectively 6.7 ± 1.3 ml and 3.9 ± 0.9 cm/s for the caudal vena cava and 2.6 ± 0.9 ml and 3.2 ± 1.2 cm/s for the portal vein. Intraobserver reliability was excellent (intraclass correlation coefficient > 0.9). Interobserver reproducibility was also excellent (intraclass correlation coefficient 0.89–0.99). Results of liver ultrasonography, cytology, and histopathology were unremarkable. Findings indicated that cardiac‐gated, phase contrast magnetic resonance angiography is a feasible technique for quantifying blood blow in canine major cranial abdominal vessels. Blood flow values from this sample of healthy beagles can be used as background for future studies on canine hepatic disease.     

Josephson tunnel-junction electrode materials

Josephson superconducting devices of the tunnel-junction type have exciting potential for use in building ultrahigh-speed computers. We consider the properties of superconducting metals that are needed for such devices that would be used in integrated computer circuits operated at a temperature near absolute zero. Recent advances in lead-alloy thin-film materials are described that have led to substantial improvements in lead-alloy Josephson device reliability. The properties of a Pb(0.84)In(0.12)Au(0.04) alloy, of Nb, and of Nb(3)Sn are discussed as examples of three different groups of materials that are of interest. Investigations of lead-alloy and niobium devices have progressed to the point that it is evident that they have good potential for fabricating integrated circuits containing large numbers of devices.