E. coli Infections in Young Lambs

E. coli has the potential to cause many problems in young lambs including watery mouth, navel ill, joint ill, scour, meningitis and septicaemia. Prompt ingestion of sufficient colostrum is the best protection against infection together with attention to navel treatments and environmental hygiene.  Despite this bacterial numbers will build over time increasing disease risk in later born lambs. The conditions listed above can be difficult to treat and often lead to lamb deaths. 

One question you should be asking this spring is whether or not the antibiotic you are recommending is capable of killing potentially significant E. coli strains present on farm. 

  • SAC Veterinary Services have data from 295 isolates of E. coli cultured from samples and post-mortem material received from lambs aged 4 weeks or less. 
  • Testing showed that 25.8% of isolates were resistant to four or more different antibiotics.
  • More specifically 52.5% were resistant to tetracyclines, 41.2% to ampicillin, 29.8% to spectinomycin, 23.7% to amoxicillin clavulanate, 13.9% to trimethoprim sulphonamide and 11.2% to neomycin.

It would be worthwhile investigating problems at lambing time at an early stage in order to establish antibiotic sensitivity patterns and inform future treatment choices. Examining untreated lambs post mortem is the best way to assess firstly if there is a bacterial aetiology  to the condition and then what the specific antibiotic sensitivity pattern is. Given that E coli can be both a commensal and a pathogen we are careful to only report and generate antibiotic sensitivity profiles for E coli isolates where we consider that the isolate is significant.

For cases necropsied on farm samples should be collected depending on the suspected disease. Watery mouth is an endotoxaemia caused by multiplication and death of E. coli within the gastrointestinal tract but most lambs have a terminal bacteraemia. If colisepticaemia is suspected liver is useful tissue to sample for bacteriology, please send tissue and/or a charcoal swab.

Due to lack of fleece, body fat and absence of rumination carcases will remain relatively fresh for a couple of days if kept in a cool place.

With reference to SAC Consulting

Related SEV Branch