Rhinitis and Sinusitis in Dogs
Overview of Canine Rhinitis and Sinusitis
Rhinitis or sinusitis is an inflammation of the mucosa (lining) of the nasal cavity or sinuses. There are many causes of rhinitis that affect dogs of all breeds and ages. Young dogs are more prone to the infectious causes and older dogs tend to develop tumor or dental disease related rhinitis. Long nosed dogs seem to be more prone to the fungal and cancerous causes of rhinitis.
General Causes of Rhinitis and Sinusitis in Dogs
Immune mediated (lymphocytic plasmacytic)
Oronasal fistula (communication between the mouth and nose)
What to Watch For
Bleeding from the nose
Pawing at the nose
Loss of appetite
Ulceration or depigmentation (losing the dark color) around the nostrils
Halitosis (bad breath)
Diagnosis of Rhinitis and Sinusitis in Dogs
Baseline tests, to include a complete blood count, biochemical profile and urinalysis should be performed on any ill animal. Additional tests may include:
Fungal serology (blood tests)
Skull, nasal, dental and chest radiographs (X-rays)
Computed tomography (CT) scan or magnetic resonance imaging (MRI)
Coagulation (clotting) profiles
Bacterial nasal cultures
Rhinoscopy and biopsy
Rhinotomy (surgical exploration of the nose) and biopsy
Treatment of Rhinitis and Sinusitis in Dogs
Removal or treatment of the underlying cause if one is found
Humidification of the environment
Keeping the external nares clean and dry
Antibiotics, antifungal therapy or parasiticides
Home Care and Prevention
Administer all medication as directed by your veterinarian. Return for follow up examinations and evaluations as directed.
In-depth information on Rhinitis and Sinusitis in Dogs
Rhinitis and sinusitis are the inflammation of the mucous membrane (lining) of the nose and sinus. They may be acute (sudden onset/short duration) or chronic (slower onset/longer duration), noninfectious or infectious, and are not an uncommon occurrence in veterinary medicine. Regardless of the underlying cause, secondary bacterial invasion/infection is relatively common.
It is important to establish the underlying cause, as treatment modalities are multiple and varied. The clinical signs and progression of disease associated with rhinitis and sinusitis may be mild and slow, however, depending on the individual case, signs may be severe and rather devastating. The appropriate diagnostics and therapeutics would be recommended and tailored to that individual.
There are several diseases/disorders that can appear similar to and/or cause rhinitis and sinusitis. These include:
Viral. These include adenovirus, distemper, parainfluenza virus.
Fungal. These include ryptococcus, aspergillus, blastomycosis, histoplasmosis and rhinosporidiosis.
Bacterial. These include primary disease (Bordatella, Pasturella) or secondary invader.
Parasitic. These include cuterebriasis, capillaria and pneumonyssoides
Foreign body – plant material, stones, teeth
Allergic/irritant – pollen, mold, litter, cigarette smoke
Immune mediated (lymphocytic plasmacytic)
Oronasal fistula (communication between the nasal cavity and mouth)
Nasal/nasopharyngeal polyp (benign fleshy growth)
Cancer – lymphoma and adenocarcinoma most common
Severe clotting (bleeding) disorders often present with epistaxis (nasal bleeding), and need to be differentiated from rhinitis and sinusitis. These include:
Thrombocytopenia (a decrease in the number of platelets) can cause epistaxis. Platelets are essential for normal clotting, and a decrease in their number is often associated with spontaneous bleeding.
Warfarin toxicity (the ingestion of rat poison) can cause epistaxis by interfering with the normal clotting mechanism.
Liver disease (to include infections, inflammation, cancer) can interfere with the normal clotting mechanism, as a normal functioning liver is necessary to produce ample clotting factors.
Disseminated Intravascular Coagulation (DIC) can be associated with epistaxis. This is an overwhelming syndrome in which spontaneous bleeding is common.
Hypertension (high blood pressure) may cause epistaxis.
In-depth Information on Diagnosis
Certain diagnostic tests must be performed to make a definitive diagnosis of rhinitis and sinusitis and exclude other disease processes that may cause similar symptoms. A complete history, description of clinical signs, and thorough physical examination are all an important part of obtaining a diagnosis, and potential underlying cause. In addition, the following tests are recommended:
A complete blood count (CBC) is often within normal limits; however, an elevated white blood cell count may be present in cases with systemic infection, and mild anemia (low red blood cell count) may be present with chronic nasal bleeding.
A biochemical profile may be within normal limits; however, it is necessary to rule out concurrent disorders.
A urinalysis is usually within normal limits.
Fungal serology (various blood tests to diagnose fungal infections) may help diagnose disorders such as aspergillosis and cryptococcus.
Skull, nasal, dental and chest radiographs (X-rays) may be very helpful in diagnosing several causes of rhinitis and sinusitis including tumors, dental disease, foreign bodies, trauma, pneumonia, and malignancies (spread of tumor into the chest).
Coagulation (clotting) profiles should be performed when epistaxis is evident to rule out other disorders. In addition, they should be considered prior to biopsy of the nasal cavity.
Bacterial cultures of the nasal cavity may be helpful in determining if there is bacterial infection and appropriate antibiotic therapy. It should be noted that although occasionally the primary cause of rhinitis and sinusitis, bacterial infection often is a secondary invader.
Cytology may confirm fungal, cancer or parasitic causes of rhinitis and sinusitis. It is a relatively noninvasive diagnostic test that can be performed by your veterinarian.