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.
Your veterinarian may recommend additional tests to exclude or diagnose concurrent conditions. These tests are not always necessary in every case, but they may be of benefit in certain individuals, and are selected on a case-by-case basis. These include:
Computed tomography (CT) scan or magnetic resonance imaging (MRI) are advanced techniques that often necessitate referral to specialty practices. These are more sensitive in diagnosing an underlying etiology.
Rhinoscopy is a procedure that allows us to visualize directly and sample tissue from the nasal cavity. It does necessitate general anesthesia, as well as the expertise of a specialist, and transfer to a facility that has the proper equipment. It may be very helpful in definitively diagnosing certain cases.
Rhinotomy (surgical exploration of the nose) and biopsy may be required for definitive diagnosis if other less invasive techniques fail to provide adequate tissue.
In-depth Information on Treatment
Most dogs are stable, and can be treated as outpatients as long as they are monitored closely for response to therapy. With appropriate therapy, and/or the identification and treatment of the underlying disorder, many patients do quite well, and some can expect to see a full recovery. In some, response to therapy can take longer and occasionally, response may be poor. It is very important that all recommendations by your veterinarian are followed very closely, and any questions or concerns that arise during the treatment protocol are addressed immediately.
Specific therapy depends on the underlying cause.
Humidification of the environment and keeping the external nares clean and dry are helpful regardless of the underlying cause.
Cure is unlikely with chronic viral rhinitis and sinusitis. Control of the more severe clinical signs with appropriate medication is often necessary, and treatment is often lifelong.
Antifungal therapy, either topical, instilled through surgically placed tubing into the sinuses, or systemically, administered orally, may be indicated in cases of fungal rhinitis and sinusitis.
Anti-inflammatory therapy (corticosteroids) may be indicated in cases of allergic or immune mediated rhinitis and sinusitis.
Rhinotomy may be necessary to remove chronically infected tissue, foreign bodies, polyps and tumors.
Radiation therapy may be indicated in patients with nasal cancer.
Chemotherapy may be helpful in cases of nasal lymphosarcoma.
Antibiotic therapy selected on the basis of bacterial culture and sensitivity. It is important to administer all medication as directed by your veterinarian. Occasionally, extended or repeat antibiotic courses are in order. In some cases, long term administration is necessary.
Follow-up Care for Dogs with Rhinitis and Sinusitis
Optimal treatment for your dog requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your dog does not rapidly improve.
Administer all prescribed medication as directed. Alert your veterinarian if you are experiencing problems treating your dog. It is important that the pet owner takes note of any clinical setbacks or onset of new clinical signs and alert the veterinarian at once.
General blood work (complete blood count, biochemical profile) may need to be re-evaluated as recommended by your veterinarian.