Over four days at the end of September — in meeting rooms and farms across the U.S. — public officials, industry representatives and everyday hog farmers were hard at work testing out plans for a worst-case scenario: What to do if African swine fever (ASF) lands in this country.

In Iowa, the focal point of this exercise was at Camp Dodge in Johnston, where Dr. Jeff Kaisand, Iowa’s state veterinarian, and Iowa Ag Secretary Mike Naig met with a team of more than 40 participants and observers at the State Emergency Operations Center.

Last week the team connected by phone with similar...