Shigatoxin producing E.coli are particularly unpleasant as even small amounts of the highly toxic poison lead to irreparable organ damage. When initial signs of the disease appear it is usually already to late for treatment. Clinically sick animals can be treated with parenteral doses of antibiotics, glucocorticoids, and antihistamines, but the treatment success is very uncertain (Orban et al. 1993). The administration of antibiotics also bears a number of risk factors:

  • Selection of resistant strains
  • distinct worsening of symptoms due to increased release of Stx2e
  • massive release of specific endotoxins in the cell wall when E.coli. die off

Consequences are shock reaction, cardiovascular failure (cyanosis) and sudden death.

Problems with oral antibiotic treatment

When administering antibiotics orally, it is difficult to ensure an effective concentration of the active ingredient as the accuracy in dosing via feed or water is limited and made even more difficult in the case of sick animals due to their reduced general state of health and thus lower feed and water intake. In addition to this, in the case of edema disease, the time span from ingestion of the medication to reach an effective concentration of the effective ingredient (time to peak effect) is usually much too long with oral medication due to the rapid course of the disease.

‘Avoidance strategy’

Until now, overcoming edema disease has been based on the so-called avoidance strategy such as

  • Restricted, well-dosed feeding after weaning
  • Use of high-end, but expensive feed compounds
  • Oral, metaphylactic use of substances that are effective against E.coli

There is a lot of good advice and numerous management tips in the literature and in practice, but the ‘avoidance strategy’ is often unsuccessful. Over a period of three years from 2006 to 2009 scientists in Belgium (Vangroenweghe et al., IPVS 2010) identified a distinct increase in pathogenic E.coli strains, which under laboratory conditions, according to the antibiotic sensitivity test, demonstrate only medium sensitivity towards colistin. This number grew from 8% of strains in 2006 to 28% of strains in 2009. (see Fig.).

The metaphylactic use of antibiotics at the time of weaning should not be conducted lightly due to the increase in resistance. The prophylactic use of antibiotics in Germany and the other EU countries has been banned since 2006. The political pressure to reduce the use of antibiotics in the farming of animals has just recently taken another massive upturn.

Weak point management

It is necessary to continuously monitor and improve hygiene standards, farming conditions and stock management. However, strategic feeding is also very important with regard to edema disease.

Common weak points are:

  • Lack of adaptation of the nursery pigs with the new feed source or feeding technique
  • Unequal feed intake due to ranking fights within the pen and unfavourable animal-feeding lot ratio
  • Separation of medicines in the feed chain

The focus in fighting edema disease must be placed on preventative measures.

These are:

  • Optimise management/hygiene (All In-All Out-procedure, good feeding lot conditions, no overcrowding)
  • Restricted feeding with feed high in crude fibre
  • No abrupt switch in feed composition
  • Acidification of feed
  • Adequate provision of drinking troughs
  • Vaccination