Other herds.
Other herds. An epidemiological investigation must be performed within 60 days of the detection of an infected animal in a herd. All herds on premises adjacent to the affected herd (adjacent herds), all herds from which animals may have been brought into the affected herd (source herds), and all herds that may have had contact with or accepted animals from the affected herd (contact herds) must be epidemiologically investigated, and each of those herds must be placed under an approved individual herd plan. If the investigating epidemiologist determines that a herd blood test for a particular adjacent herd, source herd, or contact herd is not warranted, the epidemiologist must include that determination, and the reasons supporting it, in the individual herd plan.