(CBS News) The Diamond Pet Foods voluntary recall on some of their pet food brands has been expanded after a salmonella outbreak in one of their plants left 14 people sick in nine states.

The dog food in question was was manufactured in Gaston, S.C. plant. At least five people were hospitalized from handling the food, the Centers for Disease Control and Prevention told the Associated Press.

On the official website for the recall, Diamond Pet Foods added dog food under the Country Value, Diamond, Premium Edge, Professional, 4Health and Taste of the Wild brands with a 2 or 3 in the 9th position of the production code and an X in the 10th or 11th position. The “best before” dates are between December 9, 2012 and April 7, 2013. They were distributed in a variety of eastern, southern, central and Midwest states, as well as parts of Canada, but may appear in other states.

Diamond Naturals (particularly the Lamb & Rice dry dog formula), Chicken Soup for the Pet Lover’s Soul Adult Light Formula and Diamond Puppy Formula had already been recalled in April 2011 after a random sampling showed that some of their food tested positive for Salmonella.

Some companies that co-manufacture with Diamond Pet Foods have also pulled their products, including Natural Balance, Kirkland Signature/Kirkland Signature Nature’s Domain, Apex Pet Foods, Canidae Pet Foods and one type of Wellness Complete Health puppy food. The companies claim it is a precaution because no pet or human illnesses have been reported in association with these brands nor has sample testing shown that any of their bags have Salmonella.

Reuters reported that the Centers for Disease Control and Prevention (CDC) are investigating the outbreak. The infection is possibly from people touching the dog food and then touching their own food, cross-contamination with products that touched the tainted pet food or from direct contact from a dog that had a Salmonella infection.

According to Cornell University, salmonella poisoning in humans can cause nausea, vomiting, abdominal pain/colic or cramps and diarrhea. People may experience moderate fevers and chills. The elderly and young, those with decreased gastric acidity, those with altered gastrointestinal bacteria, those who are immunosuppressed HIV patients and those whose bowel movements are decreased are at higher risk.

Pets with salmonella infections can also experience similar symptoms to infected humans, according to the Diamond Pet Foods press release. They may be lethargic or not want to eat. There is a danger with pets who are infected by do not display symptoms, however, because they may spread the disease to other humans or animals.

If symptoms are noticed, people are urged to call their healthcare providers or veterinarians for their pets.