A Salmonella outbreak linked to pig ear dog treats is continuing to spread across the US, federal health officials warn.

So far, 127 pet owners in 33 states have contracted the illness, according to the Centers for Disease Control and Prevention (CDC).

It's unclear whether those infected ate the chewy snacks, or were simply infected by touching them and then touching their mouths.

Twenty-six people have been hospitalized, but no deaths have been reported yet.

There was also no mention of dogs getting sick in the alert released on Wednesday afternoon.

The Salmonella outbreak linked to pig ear dog treats (pictured) is spreading with now 127 cases confirmed across 33 states

Dogs love pig ears.

They are chewy, dense, but not tough, making it a popular treat for both small dogs, big, old dogs and even teething puppies.

They are, in fact, so popular among the growing number of dog owners in the US that fancy recipes for preservative-free smoked pig ears for your pup are popping up online.

But the CDC and the US Food and Drug Administration are advising pet owners not to buy or feed any type of pig ear dog treats to pets.

Several companies have since recalled pig ear products due to Salmonella contamination fears including Pet Supplies Plus and Lennox Intl Inc.

Health officials believe there is no common supplier and that contact from different suppliers led to the outbreak.

For now, pet owners are urged to wash their hands thoroughly after touching their pets' food, and not to use their pet's feeding bowl for their own food.

Iowa was the hardest-hit by the outbreak with 23 cases, followed by New York with 15 and Michigan with 12.

Illnesses occurred between June 16 and July 6 affecting people who range in age from less than one year old to 90 years old.

More than 20 percent of the cases have been reported among children younger than five years old.

Salmonella infections occur after eating raw meat and eggs or foods that are contaminated with the bacteria.

Symptoms can include nausea, vomiting, diarrhea and abdominal pain that generally last between four and seven days.

According to the CDC, salmonella is the cause for 1.2 million illnesses, 23,000 hospitalizations, and 450 deaths in the US annually.

Most people can recover without treatment, although there are cases where antibiotics or IV fluids are needed.

The CDC warns those whose symptoms linger longer than a week, or that see blood in their stool, should seek medical attention.