| Popis: |
Fowl typhoid has been prevalent in one area of the United States since at least 1957, when one of us (E.E.S.) diagnosed the infection in a flock of broiler-type breeder hens. Since then, the disease has been observed with alarming regularity in both broiler and breeder flocks. In 1961, fowl typhoid that, according to field reports, did not respond to furazolidone medication was diagnosed in several broiler flocks. It was reported that the disease occurred in some flocks while they were receiving either 0.011% or 0.022%2 furazolidone (NF-180 R. T. Hess & Clark, Ashland, Ohio) in the feed. The shedding breeder flock was detected by routine blood testing and bacteriological isolation procedures, and sold. On August 4, 1962, fowl typhoid recurred on the same breeder farm, in a group of 6-month-old pullets. From August 8 to September 1, the flock was medicated with a feed containing 0.022%o furazolidone, a level previously recommended for suppressing this infection in severely infected flocks. On August 30, S. gallinarum was isolated from the livers of 4 hens that had died that day. |
