Eurytrema procyonis in a New York fox

A fox infected with canine distemper virus had multiple Eurytrema procyonis trematodes within the major pancreatic duct. The ductal epithelium was slightly hyperplastic and there was mild periductal fibrosis present. There was dilatation of the pancreatic duct containing the parasites. Numerous eosinophilic intracytoplasmic inclusions were present in the epithelium of multiple organs, including the pancreatic ducts.     

Some effects of water quality on the performance of high yielding cows in an arid climate

The water from wells in Saudi Arabia is often high in mineral content. The cows in this study had been receiving water containing between 4000 and 5000 ppm total dissolved solids. Four groups of 16 cows were calved down and milked under similar conditions in the hot summer months. Two of the groups were given normal well water and the other two groups received water after desalination in a reverse osmosis plant. One group on each type of water also had their water cooled. The groups of cows receiving treated water drank more water, consumed more concentrate and produced significantly more milk than the groups given normal well water. A similar effect on feed intake and milk production was seen when treated water was given to a 1000-cow unit with a similar number of control cows.     

Choroid plexitis in white-tailed deer (Odocoileus virginianus) in southern New York State

Brains, spinal cords, nerve roots, nerves and muscle tissues were removed from deer in southern New York State and examined for histologic evidence of infection by the causative agent of Lyme disease, Borrelia burgdorferi. There was no histologic evidence of this infection and only four of 26 deer had serologic evidence of past infection despite the fact that all were parasitized by the tick vector, Ixodes dammini. Of these ticks, 21% were carrying B. burgdorferi. In contrast, most of the deer had choroid plexitis. All but one of 48 deer tested were infected with Trypanosoma cervi, 20 of 24 deer had sarcocystis in skeletal muscles and two had dural lesions probably due to the nematode Pneumostrongylus tenuis. The causal relationship between choroid plexitis and trypanosomiasis is discussed.     

EFFECTS OF A PREVENTIVE AND SUPPRESSIVE CONTROL SCHEME ON THE DEVELOPMENT OF THIABENDAZOLE-RESISTANCE IN OSTERTAGIA SPP

SUMMARY Three years after the start of an experiment to assess the merits of thiabendazole (TBZ) treatment of trichostrongylid parasites in weaner sheep, field isolates of Ostertagia spp and Trichostrongylus spp were made from weaner sheep treated under one of three treatment schemes. Treatment frequencies were “nil”, “planned” (5 or 6/year) and “regular” (every 3 weeks). In addition an isolate was taken from a group of “tracer” sheep drenched with TBZ every 10 days. Resistance to TBZ was assessed using an in vitro egg hatch assay, pre- and post-treatment faecal egg counts and a controlled anthelmintic efficiency test. Pre- and post-treatment egg counts revealed the presence of TBZ-resistance in field isolates of mixed species. Egg hatch assays indicated a level of resistance for Ostertagia spp which was proportional to the frequency of TBZ treatment. The “planned”, “regular” and “tracer” strains of Ostertagia spp had resistance ratios for eggs of 4, 13 and 15 respectively when compared to the “nil” strain. In the anthelmintic efficiency assay treatment with 44 mg kg-1 and 88 mg kg-1 of TBZ removed 82 and 96% respectively of the total Ostertagia burden (adults and larvae) from the “nil” strain and 30 and 75% respectively from the “planned” strain. The same dose rates against the “regular” and “tracer” strains and additional rates of 132 or 176 mg kg-1 against the “tracer” strain failed to reduce the Ostertagia burden significantly. Intestinal Trichostrongylus spp from all isolates were fully susceptible to TBZ at 44 mg kg-1. Levamisole at 7.0 mg kg-1 was highly effective (99% reduction) against the “tracer” strain of Ostertagia.     

Wood energy plantations in temperate climates

Wood energy plantations are being considered in several countries for achieving greater energy independence. Many of the projects are still in research and development stages, while several programs are already operational.Maximizing the efficient production of energy by means of optimizing the growth of selected plant crops is the goal in energy plantations. For this, the bioecological factors (planting site, tree species, photosynthetic activity, soil moisture and nutrient availability), methods of genetic improvement (interspecific hybrids, clones, breeding for biomass productivity and qualities, and breeding for energy efficiency), and cultural treatments (soil preparation, planting stock, planting, spacing, weed control, fertilization, irrigation, pest control and resprouting) influencing productivity are discussed. A review of biomass yields, energy contents and ratios, production economics and conversion methods concludes the treatise.Short rotation, intensively managed plantations of genetically improved, fast growing trees can make significant contributions to energy supplies. The increased support given to this concept of energy plantations will benefit forest management in general.The environmental concerns related to intensive cultural practices in energy plantations are similar to those in agriculture. The problems are not impossible to overcome. Compared to hazards of nuclear energy, and polluting effects of coal, wood biomass remains undoubtedly a safer and healthier option.     

Externship program for large animal clinical education at the University of Minnesota: description and evaluation.

In 1970, the College of Veterinary Medicine at the University of Minnesota started an externship program as part of their large animal clinical education program. The basic idea was to work in cooperation with practitioners, using their practice world as a teaching resource. During the 1973-1974 school year, this program was evaluated by the University of Minnesota Measurement Services Center. In this externship program, senior year students spend 1 or 2 weeks in practice that closely matches each student's career interest, eg, cow-calf, dairy, swine, or zoo. The participating veterinarians are charged with the responsibility of performing as teachers during the field experience and of assisting the student in preparing a seminar topic. This seminar topic is presented in a discussion format during the spring quarter to other externship students, faculty, and attending practitioners. Since 1970, a total of 176 students have taken externships, and every year 15 to 20 group practices have participated. The principal evaluation results were based on questionnaire responses from 36 students and 20 practices during the 1973-1974 academic year. Students and practitioners indicated that the externship had been a beneficial experience for them. Many felt that the period of externship should have been longer. In general, practitioners agreed that students were able to manage most diagnostic situations and manipulative procedures that occurred during the externship. The seminar was judged by students and practitioners to be a valuable part of the program, and faculty who participated in the seminar believed that it made them more aware of field situations facing practicing veterinarians.