WellPet, makers of WellnessŪ natural pet food, are voluntarily recalling some lots of their canned cat foods due to potentially insufficient amounts of vitamin B1 (also known as thiamine).
From Wellness:
The lots involved in this voluntary recall are:

Wellness Canned Cat (all flavors and sizes) with best by dates from 14APR 13 through 30SEP13;
Wellness Canned Cat Chicken & Herring (all sizes) with best by date of 10NOV13 and 17NOV13.
If you have cat food from these lots, you should stop feeding it to your cats. You may call WellPet at 1-877-227-9587 to arrange for return of the product and reimbursement.

Early signs of thiamine deficiency may include loss of appetite, salivation, vomiting and weight loss. In advanced cases, signs may include ventroflexion (downward curving) of the neck, wobbly gait, falling, circling and seizures. If treated promptly, thiamine deficiency is typically reversible.

Please contact your veterinarian immediately if your cat is displaying any of these signs.

Letter from the company president: Information on the Voluntary Wellness Canned Cat Recall