This was a dairy cow, and dairy cows have IDs on them.
The ID was traced back to the farm in Washington. It's a dairy farm. And that farm now has been quarantined, and the owners have been very cooperative in doing that.
As soon as I landed at Malta I found that though I could go to Tunis I could not go away without being quarantined for ten days and if I remained in Malta I must stay a week.