A runny nose indicates an irritant in the nasal passages. Because irritants also produce sneezing, these two signs tend to occur together.
Excited and nervous dogs often secrete a clear, watery mucus that drips from the nose. This type of discharge is not accompanied by sneezing and disappears when the dog relaxes.
Any nasal discharge that persists for several hours is significant. A clear, watery discharge is typical of allergic and viral rhinitis, while a thick discharge suggests a bacterial or fungal infection. A nasal discharge accompanied by gagging and retching indicates a postnasal drip. A discharge from one nostril only is seen with oral nasal fistulas and foreign bodies and tumors in the nose.
Foreign bodies, tumors, and chronic bacterial and fungal infections can erode the mucous membranes and produce a blood-streaked mucus discharge or a nosebleed. Nosebleeds also occur with bleeding disorders such as von Willebrand's disease and hemophilia. Trauma, such as banging the nose, may also lead to some bloody discharge. If you see blood in the nasal discharge, notify your veterinarian.
Human cold viruses don't affect dogs. However, dogs are afflicted by a number of serious respiratory diseases that initially produce symptoms similar to those of the human cold. A runny nose, along with an eye discharge and coughing and sneezing, is an indication that you should seek veterinary attention for your dog. A yellowish discharge along with coughing and fever could indicate canine influenza and you should contact your veterinarian immediately.
Sneezing is an important early sign of nasal irritation. Occasional sneezing is normal, but if the sneezing is violent, uninterrupted, or accompanied by a nasal discharge, it's a serious condition and you should consult your veterinarian. Some dogs will sneeze if your house has a new carpet or new cleaning agents are used. Perfumes, cigarette smoke, hairspray, and even scented candles may cause your dog to sneeze.
Sneezing with a watery nasal discharge and rubbing the face with the paws is typical of canine atopy. A sudden bout of violent sneezing, along with head shaking and pawing at the nose, suggests a foreign body in the nose. Nosebleeds can occur after particularly violent bouts of sneezing.
Prolonged sneezing causes swelling and congestion of the nasal membranes. The result is a sniffling or noisy character to the dog's breathing.
Nosebleeds are caused by foreign bodies, trauma, infections, tumors, or parasites that erode the nasal mucous membranes. Some are caused by lacerations of the nostrils or puncture wounds from objects such as thorns or barbed wire. Nosebleeds are often accompanied by bouts of sneezing that aggravate the bleeding.
A spontaneous nosebleed may be a manifestation of a generalized clotting disorder such as hemophilia or von Willebrand's disease. Vitamin K deficiency is another cause of spontaneous bleeding. It occurs most often with poisoning by rodenticide anticoagulants.
Treatment: Keep the dog as quiet as possible. Apply an ice pack wrapped in cloth to the bridge of the nose. If the nostril is bleeding and the bleeding site is visible, apply steady pressure with a gauze square.
Most nosebleeds subside rather quickly when interference is kept to a minimum. If the bleeding does not stop, or if there is no obvious cause, take your dog at once to the veterinary clinic.
Dogs are nose breathers and usually do not breathe through their mouths except when panting. Mouth breathing indicates that both nasal air passages are blocked. In these dogs, no air is moving through the nose-only through the mouth. This may not be obvious until the dog becomes excited or begins to exercise.
This article is excerpted from “Dog Owner’s Home Veterinary Handbook” with permission from Wiley Publishing, Inc.