7.4 Is it safe and can I use it in breeding animals?

The safety of Enterisol^® Ileitis has been examined in both laboratory and field safety studies. No ill effects of the vaccine were observed in any of these studies. The extensive use of the product in the field with more than 100 million doses have provided further confirmation on the safety of the product.

Safety in piglets:

The safety of Enterisol^® Ileitis was examined in one week old piglets which received a ten-fold overdose of the vaccine (20 ml)

The results of this studies confirmed that there was no dissemination of Lawsonia intracellularis after vaccination with the live vaccine Enterisol^® Ileitis to unvaccinated animals. There was a transient excretion of Lawsonia intracellularis–DNA in the faeces only on Days 1 to 3 after vaccination. This effect was expected due to the normal time for excretion of orally taken material/digestion. Furthermore, there was no indication on reversion to virulence.

Safety in gilts and breeding animals:

The Enterisol^® Ileitis vaccine has been given to many pregnant sows and gilts and many boars with no ill effects. Meyns et al. (2004) investigated the safety of the vaccine in gilts. The vaccination took place at mating or three or six weeks before mating. Again the animals received a 10 time overdose.

The results showed that vaccination had no effect on general health and pregnancy results of the gilts. There was no significant rise in temperature observed, indicating that the vaccina­tion had no important inflammatory effect. Data from macroscopic, IHC and histopathological investigation revealed an overall low frequency of lesions and infections.

The authors concluded that no increase in fae­cal shedding of Lawsonia intracellularis occured after vaccination. This study confirmed the safety of the oral administration of Enterisol^® Ileitis in pre-breeding gilts, a time frame in which animals are typically most sensitive for the acute form of Lawsonia intracellularis infections.