From an AP report here
After the announcement, the company that produced the food expanded its recall to include all 95 brands of the "cuts and gravy" style food, regardless of when they were produced.
The company expanded the recall — which initially covered only cans and pouches of food packaged from Dec. 3 through March 6 — after the FDA alerted it that some products remained on store shelves.
Scientists at the New York State Animal Health Diagnostic Center at Cornell University and at the New York State Food Laboratory tested three cat food samples provided by the manufacturer and found aminopterin in two of them. The two labs are part of a network created after the Sept. 11 terrorist attacks to keep the nation's animals and food supply safe.
(Note that there have been reports of deaths prior to last DECEMBER.)