By Dr. Shannon Leggieri, DVM, MS of Claremont Veterinary Hospital, Oakland.
There are many underlying causes of nasal discharge and coughing in dogs. The cornerstone of treatment is identifying your dog’s predisposing factors.
Your dog’s age, breed, health status (including any pre existing conditions) and lifestyle are important considerations. Young dogs or dogs with weakened immune systems are more prone to viral or bacterial infections. The most common infectious cause of coughing and nasal discharge in young dogs is kennel cough.
Kennel cough is not one infectious agent but a complex of multiple viruses and bacteria. Dogs with kennel cough tend to have a dry, hacking, “goose honk” cough. Sometimes the cough will be so severe, owners will be concerned their dog is choking.
Diagnosis is usually based on clinical signs and a history including recent exposure to other dogs. Classically, your veterinarian will touch your dog’s trachea (windpipe) and quickly elicit a very reactive, dry cough. Antibiotics may or may not be prescribed based on the severity of your dog’s clinical signs and duration of illness. Regardless, your dog should be isolated from other dogs for a period of time as this complex is highly contagious. The bordetella vaccination is recommended yearly to prevent kennel cough in dogs exposed to other canines.
When assessing other causes of nasal discharge and coughing, the appearance of the nasal discharge and character of the cough becomes important. One-sided discharge only affecting one nasal cavity (nare) is more indicative of a foreign body or a nasal tumor.
The most common nasal foreign body seen in California is the foxtail. To identify nasal foreign bodies or tumors a sedated exam is essential.
Nasal tumors often require a scope (a long tube with a camera) and biopsy (microscopic examination by a pathologist). Additionally, tooth infection can cause one-sided nasal discharge as the oral and nasal cavity are connected. Hence tooth root infection can spread from the gums deep into the nasal cavity. Extraction is often curative with proper technique and suturing. Discharge from both sides of the nasal cavity indicates a more systemic process.
Infectious (whether bacterial, fungal or viral), allergic or immune-mediated diseases are the most common causes of bilateral (both sided) nasal discharge. Thick, mucoid, green or yellow discharge may indicate a more infectious process (but not always). Thorough examination, biopsy and/or culture, and imaging (ie: X-rays, CT scans) will be utilized to investigate the underlying cause and formulate a proper treatment plan.
Characterizing coughing often involves identifying whether the cough is dry or wet. Dry coughing accompanied by sneezing suggests an infectious (ie: kennel cough) or an allergic process. A wet cough indicates involvement of lower airways (i.e. pneumonia) or potentially heart disease. Cancer can also cause coughing, whether originating in the lung or spreading from other parts of the body. For diagnosis a thorough history of your dog’s symptoms will be vital.
A proper physical exam will help your veterinarian localize the origin of the cough. X-rays and bloodwork may be recommended as the first diagnostic steps. Once a cause is identified treatment will be instituted and follow up will be extremely important.