If your dog starts incessantly honking like a goose, it's likely he's suffering from a Bordetella bronchiseptica infection, often referred to as kennel cough. A bordetella infection is usually equivalent to the common cold in people, running its course in a week or two.
Extremely contagious, bordetella thrives in places with large concentrations of canines. That's why it's so common in animal shelters, boarding facilities, grooming operations and local dog parks. Also known as canine infectious tracheobronchitis, most dogs don't require more than supportive care during their bout with bordetella. However, there's always the risk that this upper respiratory infection could develop into pneumonia, especially in puppies or old or debilitated dogs. Take your dog to the veterinarian for an examination. If your vet thinks your dog is at risk for pneumonia, she might prescribe antibiotics as a preventive.
Keeping your dog in a room with a humidifier can ease some of his nasal congestion. If you don't have a humidifier, one alternative is taking your pet into the bathroom with you when you shower. He's not actually taking a shower with you, but the shower steam and vapors can relieve congestion in the same manner as a humidifier.
If your dog has difficulty breathing because of his nasal discharge, your veterinarian might recommend using saline nose drops for relief. You can use saline nose drop solution sold in pet stores, but those marketed for infants should also do the trick. More severely affected dogs might require stronger nose drops, which your veterinarian can prescribe. Don't use over-the-counter nose drops containing oxymetazoline -- the primary ingredient in Afrin -- without veterinary recommendation.
The most efficient vaccine for bordetella is administered intranasally. Although an injectable inoculation is also available, the nasal version provides protection more quickly and there's no risk of an adverse reaction at the injection site. It takes about four days post-vaccine to reach full effectiveness. While the intranasal vaccine can cause some discharge and sneezing, this is just a temporary side effect and should clear up promptly. Puppies as young as 3 weeks old can receive the intranasal vaccine. Dogs receive an annual booster treatment.