Abstract
Six SPF swine were nursed for the first three days of life and injected intranasally with a suspension of 24-hour culture of Bordetella bronchiseptica on blood agar at 6 and 12 days of age. Two of them (group A) were injected intramusculrly with 1.3g per capita of sulfamonomethoxine (SMM) five times at intervals of 6-8 days beginning at one day before experimental infection. Another two swine (group B) were treated in the same manner as group A, except that treatment was started 3 days after infection. The other two served as controls. All the swine were subjected to autopsy at 81 days of age.
At autopsy bacterial recovery was negative from the trachea in group A and from the lung in all the animals, except one control. Atrophy of the concha nasalis was found in all the treated animals, except one, and the controls. Agglutination antibody, as examined at 81 days of age, was negative in all the treated animals, except one of group B.
Gain in body weight up to 80 days of age was 30.98, 26.93, and 24.02kg, on the average, in groups A and B and the control group, respectively.
