02837nas a2200349   4500000000100000000000100001008004100002260007000043653000900113653002600122653001600148653002100164653001500185100001200200700001300212700001300225700001100238700001500249700001200264700001200276700001300288700001600301700001200317700001500329700001600344700001400360245015600374300001000530490000800540520192500548022001402473       2009                            d  c12/2009bSchlütersche Verlagsgesellschaft mbH & Co. KGaHannover10acalf10abone marrow depletion10ahaemorrhage10athrombocytopenia10acircovirus1 aE Kappe1 aY Halami1 aB Schade1 aM Alex1 aD Hoffmann1 aA Gangl1 aK Meyer1 aW Dekant1 aB-A Schwarz1 aR Johne1 aJ Buitkamp1 aJ Böttcher1 aH Müller00aBone marrow depletion with haemorrhagic diathesis in calves in Germany: Characterization of the disease and preliminary investigations on its aetiology  a31-410 v1233 aSince 2007 a new fatal haemorrhagic diathesis in calves has been observed in all areas of Germany. Analysis of 56 cases submitted for necropsy allowed its characterization. Calves fell ill within the first month of life independent of breed and sex. Only single or a few animals per herd were affected. Petechial and ecchymotic haemorrhages in many organs and tissues, particularly in skin, subcutis and gastrointestinal tract, were major findings in all animals. Microscopically a severe depletion of bone marrow cells was always observed. Lymphocytic depletion (43%) and inflammatory lesions (46%) were less frequently observed. Blood analysis of five animals indicated an aplastic pancytopenia. The resulting thrombocytopenia is regarded as major pathomechanism of this Haemorrhagic Disease Syndrome (HDS). Pedigree analysis gave no indication of hereditary disease. Tests for specific toxins such as S-(1,2-Dichlorovinyl)-L-cysteine (DCVC), furazolidone, or mycotoxins resulting in bone marrow depletion were negative. Bacterial infections, Bovine Viral Diarrhoea Virus, and Bluetongue Virus were ruled out as cause of the disease. HDS shares similarities with a circoviral infection in chickens (chicken infectious anaemia). A broad-spectrum PCR allowed detection of circoviral DNA in 5 of 25 HDS cases and in 1 of 8 non-HDS cases submitted for necropsy. Sequencing of the whole viral genome revealed a high similarity (up to 99%) with Porcine Circovirus type 2b. Single bone marrow cells stained weakly positive for PCV2 antigen by immunohistochemistry in 1of 8 tested HDS animals. This is the first report of circovirus detection in cattle in Germany. The exact cause of HDS still remains unknown. A multifactorial aetiology involving infection, poisoning, immunopathy, or a genetic predisposition is conceivable. Additional research is necessary to clarify the pathogenesis and the potential role of PCV2 in HDS.  a0005-9366