Salmonellosis - calf diarrhoea

SALMONELLOSIS Aetiology: Important cause of d+ Particularly when calves are brought together from variety of sources and Raised intensively on milk replacer diets Common isotopes: S. typhimurium S. dublin Studies show —> ~5% cattle shed Herd level risk factors: Access to surface water Disposal of manure in liquid from on pasture used for grazing Eating forage from fields where manure has been applied Shedding of organism in high numbers from carrier + poor management (crowding, dirty etc) —> naive cattle affected BVDV increases risk Recovered adult animals can become carriers 4 syndromes: Per-acute septicaemia Acute infection Chronic enteritis Carrier state Acute, chronic, or carrier intestinal infections shed organisms —> faecal-oral route Peracute or acute often septicaemia —> shed organisms from other secretions AGE: 7-10 days old Incubation 12-24 hours CLINICAL SIGNS:Peracute septicaemic infection: So acute and fatal!!!! —> few clinical signs: Diarrhoea Depression Dullness Early high fever 40.5 to 42C Abdominal distension With S dublin calves may also show nervous signs of Incoordination Nystagmus Death usually occurs within 24-48hrs Acute infection: Depression Early high fever (40-41C) Severe watery diarrhoea, with putrid odour May see fresh mucous and blood in diarrhoea Rapid dehydration Precipitous drop in the animals temperature with the onset of the diarrhoea Some cases pneimonia, arthritis, physics and meningitis Chronic infection: Chronic or intermitten diarrhoea Weightloss Hypoproteinemia Failure to thrive Some calves may have had acute salmonellosis DIAGNOSIS:Isolation of the organism + history and clinical signs Faecal cultures to identify S. typhurium Faecal, blood, transtracheal or lung tissue may be necessary to isolate S. Dublin Peracute deaths —> necropsied —> samples of ilium, caecum, or colon TREATMENT: Fluid therapy Whole blood transfusion in valuable animal Antibiotic therapy: ONLY to calves with parachute or acute signs Mild-chronic infections do not benefit Culture and sensitivie —> ceftiofur, TMS 5-7 days Single in of csts or flunixine IV + fluids CONTROL: Achieve diagnosis Isolate infected animals —> carriers will be difficult Quarantine