A pet food recall first announced last month has been expanded, the manufacturer says.

Hill's Pet Nutrition recalled 22 canned dog food products in February, including popular brands like Science Diet and Prescription Diet.

On Wednesday, Hill's said in a statement that it was expanding the voluntary recall. The list now includes 31 products

The specified canned dog food has been recalled because of excessive levels of vitamin D, which can lead to serious illness and death.

Dogs that eat too much vitamin D can experience vomiting, loss of appetite and excessive weight loss. The company blames a supplier error for the problem.

In most cases dogs recover after they stop eating the product. However, some pet owners took too social media after the recall sharing stories about their dog’s illnesses and deaths.

“We care deeply about all pets and are committed to providing pet parents with safe and high quality products. Hill’s has identified and isolated the error and, to prevent this from happening again, we have required our supplier to implement additional quality testing prior to their release of ingredients. In addition to our existing safety processes, we are adding our own further testing of incoming ingredients. All products within Hill’s control have been placed on hold. Hill’s will be contacting all customers to retrieve products. For further information, please contact Hill’s Pet Nutrition, Inc. at 1-800-445-5777 Monday-Friday during the hours of 9 a.m.-5 p.m. (CST) or at contactus@hillspet.com," the company stated on its website.

Customers who have purchased products with the specific lot/date codes are urged to discontinue feed and throw to throw it away. The company has offered to replace it at no cost.

A complete list of products is available online.