Microbiological, Pathological and Histological Findings in Four Danish Pig Herds Affected by a New Neonatal Diarrhoea Syndrome29 October 2013
Researchers in Denmark have identified a new enteric disease of young piglets, which they have named New Neonatal Porcine Diarrhoea Syndrome (NNPDS). It does not appear to be caused by any known pathogens or management factors.
Neonatal diarrhoea is a frequent clinical condition in commercial swine herds, previously regarded to be uncomplicated to treat. However, Hanne Kongsted of the Danish Pig Research Centre reports that, since 2008, it seems that a new neonatal diarrhoeic syndrome unresponsive to antibiotics and common management practices has emerged. Routine laboratory examinations have not detected any pathogen related to this syndrome.
In a study with co-authors from the National Veterinary Institute and the University of Copenhagen published in BMC Veterinary Research, the primary purpose was to evaluate whether well-known enteric pathogens could be associated with outbreaks of neonatal diarrhoea, thus question the hypotheses of a new syndrome.
Furthermore, the researchers wanted to evaluate macroscopic and microscopic findings associated with these outbreaks and if possible propose a preliminary piglet-level case-definition on syndrome New Neonatal Porcine Diarrhoea syndrome (NNPDS).
Four well-managed herds experiencing neonatal diarrhoea with no previously established laboratory conclusion and suspected to suffer from New Neonatal Porcine Diarrhoea Syndrome, were selected.
Within these herds, 51 diarrhoeic and 50 non-diarrhoeic piglets at the age of three to seven days were necropsied and subjected to histological and microbiological examination.
Faeces were non-haemorrhagic.
Neither enterotoxigenic E. coli, Clostridium perfringens type A or C, Clostridium difficile, rotavirus, coronavirus, Cryptosporidium spp, Giardia spp, Cystoisospora suis nor Strongyloides ransomi were associated with diarrhoea in the investigated outbreaks.
Macroscopically, the diarrhoeic piglets were characterised by filled stomachs and flaccid intestines without mucosal changes. The predominant histological lesions were villous atrophy in the jejunum and ileum. Epithelial lesions in colon were seen in one-third of the case piglets.
Kongsted and co-authors concluded that their results support the hypothesis that a new neonatal porcine diarrhoea was present in the investigated herds, since no known pathogen(s) or management factors could explain the diarrhoeal outbreaks.
Based on the findings in the four herds, they suggested the following case-definition of NNPDS: non-haemorrhagic diarrhoea during the first week of life, without detection of known infectious pathogens, characterised by milk-filled stomachs and flaccid intestines at necropsy.
Kongsted H., B. Jonach, S. Haugegaard, Ø. Angen, S.E. Jorsal, B. Kokotovic, L.E. Larsen, T.K. Jensen and J.P. Nielsen. 2013. Microbiological, pathological and histological findings in four Danish pig herds affected by a new neonatal diarrhoea syndrome. BMC Veterinary Research. 9:206. doi:10.1186/1746-6148-9-206
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