Some epizootological features of pig nematode in Estonia
2001
Kaarmaa, A. | Maegi, E. (Estonian Agricultural Univ., Tartu (Estonia). Inst. of Veterinary)
Helminthocoprological investigations were carried out on 9 large pig farms in last 10 years and the results of 150 separate swine populations were analysed. On the basis of the results of our observations can be concluded: The main digestive tract parasites in swine are Ascaris suum and Oesophagostomum spp. roundworms. Invasion caused by Strongyloides ransomi can be detected only in a few swine populations. Trichocephalus suis invasions with low extensity were registered as natural disease foci. Age dynamics has been observed by Ascaris suum invasions: extensity of invasion rose up to six month and after that spontaneous recovery was observed. Reinvasions were not detected because of developing immunity of older pigs. Age dynamics developed in Oesophagostomum spp. invasions: extensity of invasion occurred to be in correlation with swine age. Invasions of breeding sows indicate the absence of immunity. Invasions with Strongyloides ransomi is directly connected with age of pigs: high extensity of invasion was observed up to 4th months of age, after that the invasion extent diminished to 1,2 per cent in breeding sows. Trichoephalus suis was diagnosed rarely. Extent of invasion rose with pig age, but according to our data, not exceeded 10 per cent of total populations
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