Salmonellosis - calf diarrhoea

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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