Canadian health officials have issued alerts for possibly tainted dip and meat products.The Canadian Food Inspection Agency said on its Web site Canada Safeway Ltd. is warning the public not to consume certain Signature Cafe 6-Layer Dip products imported from the United States because of possible contamination with Listeria monocytogenes. The products included in the alert are Signature Cafe 6-Layer Dip, 425 grams, 58200 06034; and Signature Cafe 6-Layer Dip, 850 grams, 58200 06032. Both have best-used-by dates of Sept. 16 and were distributed nationally. The agency also said Saturday My Country Delicatessen Ltd. in Niagara Falls, Ontario, is warning the public not to consume the ready-to-eat meat products sold at its deli counter on or before Aug. 10 because they may be contaminated with Listeria monocytogenes. Listeria monocytogenes can cause high fever, severe headache, neck stiffness and nausea. Food contaminated with it may not appear spoiled.The agency said Friday White Veal Meat Packers Ltd. of Toronto is warning the public not to consume certain veal tongue and veal cheek meat products that may be contaminated with E. coli O157:H7. No illnesses had been reported.The veal tongue was sold by Les Caprices D\'Al Adhba Inc. in Laval, Quebec, in early June and at Super Tehran in Toronto, in early June.The veal cheek meat was sold by Boucherie Marcelleria Bari Inc. in Montreal from June 1 through Friday.No cases of illness had been reported associated with any of the products covered by the alerts.