Dogs are prone to colds just as human beings are and dog cold can be caused by a variety of factors.
Dog cold causes include virus attacks, seasonal changes, undue stress, travel and close contact with other infected dogs. The cold is likely to go way on its own, but if your dog seems afflicted for a long period of time, it would be advisable to consult its doctor immediately. Eye discharge, a greenish yellow mucous, vomiting and fever are accompanying symptoms to be careful about.
Adult dogs that are advanced in age and young puppies need to be taken to the vet if they develop symptoms of a cold and cough as their immune systems are not strong enough and the may be suffering from some other underlying condition. If your dog is coughing along with the cold, you can if you wish, give it a cough suppressant in consultation with the veterinarian. But in most cases, the cough is useful for it to get out the air ways.
Hence you can use steam to liquefy the mucous and allow it to breathe easy.
One method would be to steam up your bathroom and place your pet in it. Cupping your hands while patting the dogs back will help ease the congestion too. Using a mist vaporizer can help the dog to a great extent. Dog cold treatment involves feeding it a lot of water and other liquids to make up for the fluid it loses from the cold and also because most dogs keep away from fluids when sick, which only dehydrates them and aggravates their condition. If it is averse to drinking plain water, add a little chicken broth to it for a change in taste. Feed it a little extra, a bowl of brown rice or a boiled chicken to entice it to eat and to keep up its energy and strength. The dog should be isolated from other animals as this not only prevents it from spreading the infection, but also protects it from other infections that may affect it due to its weakened immune system. Multivitamin dog supplements might help during this period as it may be off its food and may not be getting sufficient nutrients. Consult your veterinarian over this as vitamin A, C and E are particularly beneficial during this period. Make sure that the pet is warm and dry at all times, and keep him in the house if it is cold outside.