Atrophic rhinitis in swine fattener herds. A field study of the spread of the disease with infected pigs bought at market.

In three different fattener herds pigs primarily AR infected as baby piglets were mixed in the fattening units with healthy pigs at an age of 11--13 weeks. Snout alterations were registered on cut snouts at a slaughter weight of about 70 kg. Severe AR was registered in the groups of primarily infected pigs (Tables I--III). The incidence of snout alterations was lower in the groups of pigs infected at an age of 11--13 weeks, but was much higher than in the groups of healthy control pigs or in the normal pig population in the region (Table IV). The results indicate that pigs infected at a rather late age in the fattening units can develop severe atrophic rhinitis.