Gastrointestinala parasiter hos strusfåglar i Sverige

Paper in Swedish.

English title: Gastrointestinal parasites of ratites in Sweden.

Summary:

Ratites, especially ostriches have become new popular species for farming purposes in Sweden, and many birds were imported during the 1990s.

Fresh pooled fecal samples were collected on 45 ostrich farms, six emu farms and one rhea farm on a single occasion during May to June in 1999 in order to investigate the farm prevalence of gastrointestinal parasites in ratites on Swedish farms. In total, one to six samples were obtained from different age groups from each farm. Parasitological examination was performed using previously described methods and nematode eggs were differentiated by larval culture.

Gastrointestinal parasites were detected in fecal samples from 28 of the 45 ostrich farms. The wireworm was found in 30 samples from 18 of the ostrich farms (40%) whereas Codiostomum struthionis, Balantidium sp. Entamoeba sp. and Isospora spp. were identified on fewer farms. The prevalence of L. douglassii was highest in the breeder birds whereas only occassional positive amples were found among chickens and subadults.

The farm prevalence of gastrointestinal parasites in ratites on Swedish farms, particularly L. douglassii in the ostrich, was surprisingly high. The cause of this finding is not kown. The high frequency of international and national trading of ratites in the 1990s, high stocking densities during transit, on trading farms and in quarantines as well as lack of successful anthelmintic treatment in quarantines may all have contributed to the results in this study.

The impact of parasite ifections in Swedish ratites is not fully known. However, two case recpors with fatal outcome in young ostriches infected with L. douglassii are described in the paper. The findings at necropsy included proventriculitis and hemorrhagic/necrotising enteritis associated with E.coli. In the second case, a two year old hen which was found dead in a Swedish quarantine numerous larvae of L. douglassii were not only found in the proventriculus, but also embeded in the koilin layer of the gizzard. The koilin layer of the gizzard was severely thickened, unusually soft and inflamed. The localisation of larvae of L. douglassii in the koilin layer of the gizzard has, to the best of our knowledge, not been previously reported in the literature.

Note: Lice mentioned in Introduction.