I'm sorry you're experiencing this. It's good that she had her Bordetella vaccine, and I hope it was given at least 2 weeks before she went to the kennel for maximum protection. Most of the time when dogs start coughing after a kennel stay, it's due to an upper respiratory virus. There isn't much you can do for a virus other than to support the immune system with good nutrition and minimizing stress. Eventually the dog will get better without any treatment. However, if the dog is coughing so much that she vomits up her food and isn't resting well, that will suppress her immune system and delay her recovery. If she doesn't have a fever or lethargy, and she isn't coughing up mucus, she probably doesn't need an antibiotic, but she might benefit alot from a cough suppressant which will allow her to get some rest and keep her food down. A visit to her vet. will be necessary to make sure there are no signs of pneumonia. If not, the vet. can prescribe a cough suppressant to give her (and you) some relief. Do not give her the hydrogen peroxide with honey unless you want her to vomit more. Hydrogen peroxide is commonly used to induce vomiting in dogs that have eaten something they shouldn't have. Good luck. I hope she's feeling better soon. Kennel cough is VERY common in any kennel or shelter situation, even when dogs are properly vaccinated. The vaccine helps to protect the dogs from a more serious bacterial infection that can take hold when they are stressed out and coughing alot.