Infection with intestinal Parasites can in many cases be the reason for decreased performance or production. The gastro-intestinal nematode, Ostertagia ostertagi, and the lungworm, Dictyocaulus viviparus, are the most pathogenic nematodes of cattle and severe infection can lead to death. They have both a direct lifecycle and on the pasture the Parasites spread as freeliving worms. The Parasites are mainly a problem for the first season grazers. They have not developed immunity against the Parasites and are therefor more sensitive to parasite infections.

Risk-based sampling program of microorganisms in the water source in northern SwedenAfter several disease outbreaks caused by Parasites in the drinking water during the last years, it is more essential than ever to insure that the water supply companies have enough barriers to counteract the presence of microorganisms in the outgoing water. It is also discussed whether climate changes such as increased precipitation can have a connection to the increased cases of Parasites in water sources. The water source at Gäddvik is Luleå municipality?s largest and provides drinking water to 64 500 of Luleå?s 74 000 inhabitants. The investigation of microorganisms in the water source, especially in the Lule River has not been as prioritized as the sampling of chemical parameters.

Healthy, natural pastures is very valuable for biodiversity in the form of both plants and animals. An efficient use of pastures helps to preserve biodiversity, but grazing animals needs to be de-wormed to keep them healthy and to prevent harmful Parasites spread on the pasture. The awareness about the environmental impact of the frequent use of deworming agents is low among the public. Some people are unaware that the absorption in horses of anthelmintics is incomplete, which make the circumstances about enviromental effect important to investigate further. The scientific evidence in this area is limited and more studies and trials are needed to deepen the knowledge about the effects of anthelmintics in the environment.

In the report Parasites in the gastrointestinal tract and easily visible external symptoms of disease in capercaillie, (Tetrao urogallus), was taken into account. The study was based on results from the examination of 62 fresh faecal samples, collected in spring 2003, and postmortem examination of 22 frozen birds that were collected between 1999 and 2003. All of the samples principally were from the north of Sweden. In total, 4 species of Parasites, but no significant symptoms of disease were found. In the faeces low levels eggs of the roundworms Capillaria spp. (125 epg) and Ascaridia spp.

Perch (Perca fluviatilis) is a very popular fish in Sweden and it is common in Swedish waters. In some areas along the Swedish coast the perch population has decreased. It is therefore important to get a view at the health status of perch. During April, July and August of 2008, a total of 346 perches were caught in the Gump Bay in the Botnian Sea. The fish were mainly caught by net but also by rod.

Drinking water is produced from raw water and is either from groundwater or surface water. This thesis aims to find out if the cleaning process of raw water is sufficiently effective. This is important because consumers are otherwise at risk of waterborne infection caused by pathogens. There are three groups of pathogens; bacteria, virus and parasite. These have different characteristics which mean that they require different water treatment to be separated.

Drinking water is produced from raw water and is either from groundwater or surface water. This thesis aims to find out if the cleaning process of raw water is sufficiently effective. This is important because consumers are otherwise at risk of waterborne infection caused by pathogens. There are three groups of pathogens; bacteria, virus and parasite. These have different characteristics which mean that they require different water treatment to be separated.

Drinking water is produced from raw water and is either from groundwater or surface water. This thesis aims to find out if the cleaning process of raw water is sufficiently effective. This is important because consumers are otherwise at risk of waterborne infection caused by pathogens. There are three groups of pathogens; bacteria, virus and parasite. These have different characteristics which mean that they require different water treatment to be separated.

Drinking water is produced from raw water and is either from groundwater or surface water. This thesis aims to find out if the cleaning process of raw water is sufficiently effective. This is important because consumers are otherwise at risk of waterborne infection caused by pathogens. There are three groups of pathogens; bacteria, virus and parasite. These have different characteristics which mean that they require different water treatment to be separated.

Anthelmintic resistance is a major problem in sheep husbandry all over the world. One way toslow down the development of anthelmintic resistance is to keep part of the parasitepopulation in refugia (unexposed to drugs) which will maintain the genes for susceptibilitywithin the population. Climate, type of parasite and drenching regimes effect the size of therefugia. Dilution of resistant with susceptible Parasites, targeted treatment and targetedselective treatment are all management strategies that employ refugia. Dilution is possible butcomplicated.

Sub-lethal doses of neonicotinoids have been shown to negatively impact the health of honeybees. However, most studies to date have exposed bees only artificially to these pesticides under laboratory conditions. There have been just a few well designed and replicated studies of the impacts of realistic neonicotinoid exposure on honeybees foraging under field conditions. In order to close this knowledge gap, and to test the influence of the neonicotinoid clothianidin on honeybees, we used a study system of 16 paired, spatially separated (>4 km) spring oilseed rape fields in the south of Sweden. The fields were paired according to land use, the surrounding landscape and geographical proximity, using GIS.

This literature review describes organic pig production in Sweden, its advantages and disadvantages, but also how its problems can be reduced or solved. Organic pigs have the possibility to a more natural behaviour than conventional pigs. With outdoor pigs comes problems, especially during wintertime, concerning water and feed supply, thermal environment and supervision. Parasites and leakage of plant nutrients are other difficulties that comes with outdoor pigs. All problems and difficulties can be reduced or put right through correct management.

Twenty-four calves, which had not grazed previously, were divided into four groups. They were subsequently inoculated orally with either E. alabamensis oocysts, O.ostertagi/C. oncophora larvae, or both. One group remained uninfected and was used as a control.

The aim of this study was to document treatments of sick and injured reindeer in Tornedalen and the area around Gällivare. I also wanted to find out the basis for the treatments, how they are considered to work and if they agree with established veterinary science. The occurrence of ?folk remedies? was especially studied. In all, 40 reindeer owners were interviewed.

American bison (Bison bison bison) is a new species in Sweden and was introduced in the year 2000. In this study the result of an interview and a field investigation is presented. The aim was to investigate the health and parasite status in Swedish bison herds. The most common reason to begin with bison breeding was meat production and/or sale of breeding animals and tourism. The Swedish breeder?s experience of bison is that they in general are healthy.