TABLE 1.

Characteristics of the six swine operations used in this study

Site	Type of facility	Pig capacity	% of pigs affected	Clinical signs
A	Finisher	1,200	3	Rhomboid skin lesions, swollen joints, lethargy
B	Finisher	2,200	2	Rhomboid skin lesions, swollen joints, lameness, pyrexia, lethargy
C	Breeding herd	1,600	2	Swollen joints, lameness, abortions
D	Boar stud	150	1	Rhomboid skin lesions, swollen joints, lameness
E	Finisher	2,400	2	Rhomboid skin lesions, lameness
F	Breeding herd	1,100	4	Acute death, rhomboid skin lesions, cyanosis of skin, abortions