A hidden danger at summer cookouts for dogs: Corn on the cob. Here’s why it can be deadly.

• Dogs can eat corn, but should not be given corncobs with or without corn on them.
• Dogs can chew up and eat corncobs but cannot digest them, which could be fatal.
• Corncobs can cause choking or become stuck in a dog’s digestive tract, requiring surgery.

Most dog owners know pooches shouldn’t have chocolate. But there’s another common food your dog shouldn’t chow down on: corn on the cob.

That means warm weather cookouts and gatherings will soon present a surprising danger for dog owners’ furry friends.

Dogs can eat corn – it is an ingredient in many commercial dog foods – and can be part of a well-balanced diet for your pet, according to the American Kennel Club. (Just make sure your dog isn’t allergic to corn before giving them some.)

But corn on the cob is a no-no for dogs because the cob is indigestible. Eating some of it could mean surgery – or even death – for your dog. 

So dogs can eat corn, but not corn on the cob? Why is that?

Unlike chocolate, corn on the cob doesn’t contain toxins that are dangerous to dogs. The problem here is that dogs cannot digest the cob itself.

“The biggest concern is the potential for the cob to get stuck in the digestive tract,” said Dr. Tina Wismer, senior director of toxicology at the American Society for the Prevention of Cruelty to Animals’ Animal Poison Control Center.

But corn itself — whether from the cob, a can or in dog food — can be a healthy part of a dog’s diet.

Corn contributes vitamins and minerals and is a rich source of linoleic acid, an essential fatty acid that dogs must get in their diets, according to the Cummings Veterinary Medical Center at Tufts University.

Your dog just ate chocolate:Here’s what to know and what you need to do first.

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My dog gnawed on and ate part of a corncob. What do I do?

Because corncobs are hard to chew and undigestible, they do not break down when passing through the digestive tract, often causing blockage and sometimes perforation, said Michael San Filippo, spokesperson for the American Veterinary Medical Association. 

Depending on the size of the dog and the amount ingested, pet owners should call their veterinarian if their dog eats corncob, Wismer said.

Corncobs seem tough, but they are “quite fibrous at the core,” she said. “Some dogs will chew them into small enough pieces to pass while others will swallow them whole or in large chunks.”

How much corncob a dog could possibly consume without serious injury depends on its size and the diameter of the intestine, Wismer said. A medium to large dog has a diameter of 9-10 mm (0.35-0.39 inch), while small dogs have a 5.5 mm (0.2 inch) diameter at the smallest part of their digestive tract. “So pieces that can move out of the stomach can get stuck further down,” she said.