SALMONELLOSIS

Causative Agent(s)

Salmonella enterica

Clinical Presentation and Epidemiology

There are two major syndromes: a systemic septicaemia (also termed as typhoid) and an enteritis. Other clinical presentations include abortion, arthritis, respiratory disease, necrosis of extremities, and meningitis.

Diagnostic Considerations

Faecal samples are used for culture and isolation of Salmonella enterica.

Serologic tests to identify specific antibodies in serum or milk are available and are increasingly used as a diagnostic tool in salmonellae surveillance.

Management and Treatment

Carriers of salmonellosis and contaminated feedstuffs and environments are major problems. Drain swabs or milk filters may be cultured to monitor the salmonellae status of a herd. The principles of control include prevention of introduction and limitation of spread within a herd.

Culture and sensitivity tests should be conducted before administration of antibiotics for effective treatment and also to prevent development of resistant strains.

Trimethoprim + sulphadiazine 30 mg/kg PO, q24h 15-24 mg/kg IM or slow IV, q24h x 5- 7/7
Ampicillin 2 mg to 5 mg/lb IM, SID, 6/7
Enrofloxacin 5-5 mg/kg IM, daily for 3-5 days for calves. 2.5-5 mg/kg SC once daily for 3-5 days or 7.5-12.5 mg/kg once for adult cattle.
Gentamicin 5 mg/kg IM
Ceftiofur 1-2.2 mg/kg daily x 5-7/7
Ceftriaxone 15-50 mg/kg q12-24h IM x 3-5/7

Antibiotics such as ampicillin or cephalosporins lead to lysis of the bacteria with release of endotoxin, providing an indication for the use of NSAIDs to reduce the effects of endotoxemia. If oral medication is chosen, it should be given in drinking water and not mixed into solid feed, because affected animals are thirsty due to dehydration and their appetite is generally poor. Fluid therapy to correct acid-base imbalance and dehydration may be necessary.