The short answer: No.
The long answer: A cob is the central core of an ear of corn. Cylindrical in shape, it is where corn kernels are attached. It is not advisable for your dog to eat a corn cob because of its tough, woody nature. Just a small portion of it could block his airway passage, cause tears to his internal organs, or create problems in his digestive system.
In general, dogs can enjoy eating a few pieces of cooked corn kernels. However, these kernels must not be flavoured with salt, herbs, and spices (such as garlic and onions), and must be removed from the cob before they are served to your dog. Smaller dogs also have a higher risk of choking on the corn kernels, so it’s advisable to monitor them while consuming the grain.
What to do if your dog accidentally eats a corn cob: Speak to your veterinarian about your dog’s situation. Take note of how much corn cob he ate, monitor his breathing, and see if he swallowed the piece without getting hurt. If he is choking on a cob, he may exhibit symptoms such as extreme distress, drooling, pawing at the mouth, producing choking sounds, rubbing his face along the ground, gagging, and retching. You should also observe him for signs of intestinal distress in the form of lack of appetite, lethargy, pain, and constipation. If your dog vomits, collapses, or completely loses his appetite, bring him to the emergency clinic immediately. Your vet may induce vomiting to remove the cob or may perform endoscopic surgery.
In summary: Though corn kernels are packed with fiber, vitamins, potassium, and folic acid that are good for your dog, corn cobs should be kept away from him as they are made of highly indigestible cellulose, hemicellulose, and lignin. No good will come out of him playing with the cob or munching on it like a bone, so be sure to dispose of it properly.