Nasal Polyps In Dogs: Causes, Symptoms, and Treatments
Nasal polyps in dogs are non-cancerous growths of tissue inside the nasal cavity. The disease is caused by chronic inflammation of the nasal mucosa, otherwise known as rhinitis.
Nasal polyps occupy space inside the cavity and cause damage to the underlying structures.
Symptoms of nasal polyps include nasal discharge, stertor (noise when breathing), sneezing, and face pawing. Any bump on dogs nose is indicative of nasal polyps.
Bumps on dogs nose allergies leading to polyps occur due to various factors, including inhaled allergens and environmental irritants.
Treatment for nasal polyps includes surgical removal, radiation therapy, and steroids. Surgical removal is the most popular treatment for dog nasal polyps.
What is Nasal Polyps In Dogs?
Nasal polyps in dogs are tissue outgrowths attached to the nasal mucosa by a stalk. A polyp is a harmless, non-cancerous bump on a dog's nose that causes nasal problems. Nasal problems in dogs, such as nasal polyps, are associated with chronic rhinitis or inflammation of the nasal mucosa. The polyps develop due to trauma, infection, and anatomical defects.
Why do Dogs have Nasal Polyps?
Dogs have nasal polyps due to persistent inflammation of the nasal mucosa. Long-term swelling and inflammation from chronic rhinitis cause abnormal tissue proliferation. Infections, viruses, and allergies cause chronic rhinitis. Nasal polyps resemble a mass of pink tissue in or on the nose. The polyps cause discomfort for the dog during respiration.
How Does Nasal Polyps Affect Dogs?
Nasal polyps affect dogs by causing breathing difficulty, pain, and discomfort. Nasal polyps occur outside or inside the nose, occupying a portion of the lumen of the nose.
The compromised nasal passages for air entry make respiration difficult for the dog, leading to persistent sneezing and an audible sound (stridor) when breathing.
Extensive nasal polyps alter the dog’s sense of smell by affecting the underlying structures and olfactory receptors on the nasal mucosa. A nose with nasal polyps vs normal noses in dogs has seemingly smaller nostrils. The visual change is due to the hard bump inside the nose.
Is Nasal Polyps Cancerous?
No, nasal polyps are not cancerous. Nasal polyps are not metastatic and are considered benign tumors of the nose. Nasal polyps cause problems in respiration due to a disruption in the normal anatomy of the nasal cavity. The serious types of cancer in dogs that involve the nose are nasal adenocarcinomas and sarcomas. The cancer types are not the same as nasal polyps.
Are Nasal Polyps in Dogs Hereditary?
Yes, nasal polyps in dogs are hereditary. Nasal polyps in dogs have been linked to genetic and environmental factors. Studies have connected nasal polyps to a recessive autosomal mode of inheritance in humans.
One study conducted on thirteen related patients with nasal polyps concluded that “the presence of consanguineous unions in this family suggests the possibility of a common ancestor.” according to Delagrand et al., in a study entitled “Nasal polyposis: is there an inheritance pattern? A single-family study,” 2008. The research findings indicate similar levels of hereditary involvement among canines.
What Causes Nasal Polyps In Dogs?
The causes of nasal polyps in dogs are listed below.
- Chronic Bacterial Rhinitis: Bacterial rhinitis occurs due to the presence of a foreign body or loss of adequate filtration mechanisms of inspired air. Causes of bacteria rhinitis are Aspergillosis and Kennel Cough. Nasal polyps occur when bacterial rhinitis is left untreated and inflammation persists for an extended period.
- Chronic Fungal Rhinitis: Fungal rhinitis is commonly caused by Aspergillus fumigatus. The disease is contracted through inhalation of shed microscopic spores in the air. Fungal rhinitis causes nosebleeds and chronic nasal discharge with a strong odor that persists for months and does not respond to antibiotics and other therapies. The long-term nature of fungal rhinitis predisposes the dog to develop nasal polyps.
- Chronic Allergic Rhinitis: Allergic rhinitis is triggered by inhalant allergens such as dust, pollen, smoke, and irritant gases that activate the dog’s immune response. The allergy causes inflammation of the nasal mucosa, leading to signs such as head shaking, sneezing, and nose rubbing. The inability to identify and avoid inhalant allergens leads to chronic allergic reactions that inflame the mucosa.
- Chronic Viral Rhinitis: Viral infections are the main cause of sudden rhinitis in dogs. Diseases such as canine distemper, adenovirus types 1 and 2, and canine parainfluenza are common contagious respiratory diseases in dogs. Failure to treat viral respiratory infections promptly leads to long-term damage. Dogs with poor immune systems have a slower recovery rate and suffer from rhinitis for prolonged periods.
- Lymphoplasmacytic Rhinitis: Lymphoplasmacytic rhinitis, or idiopathic lymphoplasmacytic rhinitis (LPR), is a severe form of non-infectious rhinitis. The chronic nature of LPR predisposes affected dogs to develop nasal polyps.
What are the Signs and Symptoms of Nasal Polyps in Dogs?
The signs and symptoms of nasal polyps in dogs are outlined below.
- Sneezing: Nasal polyps are abnormal tissue outgrowths that irritate the mucosal lining of the nose. The body recognizes the polyps as foreign in the nasal cavity and attempts to force them out through sneezing as a physiological response.
- Face Pawing: Face pawing is a compensatory mechanism by which the dog tries to relieve the discomfort caused by the polyps. The dog scratches its nose or drags its nose on the ground to alleviate the pain.
- Stridor: Stridor is a sound that emanates from the dog’s nose during breathing and usually is inaudible. The foreign mass of tissue in the nose invades the space and causes a narrowing of the circumference. The result is a high-pitched, wheezing sound as air passes through the cavity.
- Nasal Discharge: Nasal discharge is a common sign of rhinitis in dogs. Chronic rhinitis causes nasal polyps, which coincide with rhinitis.
- Open Mouth-breathing: Nasal polyps interfere with respiration. The tissue mass occupies the nasal cavity, reducing the space for air to enter and exit. Large nasal polyps significantly reduce airflow and disrupt breathing. The dog tries to breathe through the mouth as a compensatory mechanism.
How is Nasal Polyps in Dogs Diagnosed?
Nasal polyps in dogs are diagnosed through veterinary examination. The veterinarian examines the nasal cavity for bumps and lumps. The polyps occur inside the nostril or further back, requiring a rhinoscope.
A rhinoscope is a long, tubular instrument with a camera at the end that checks the nasal passages. The dog is sedated, and the tube is guided into the nasal cavity, which scans for abnormal growth. Histologic examination determines whether the growth is a simple polyp or a cancerous tumor.
What are the Stages of Nasal Polyps in Dogs?
The stages of nasal polyps in dogs are listed below.
- Stage 1: The polyps are localized to the middle nasal meatus between two conchae. Stage 1 polyps stay within the free edge of the middle turbinate.
- Stage 2: The polyps invade the nasal turbinates, causing respiratory distress. The affected turbinates have inadequate space to facilitate proper airflow.
- Stage 3: Polyps make contact with the floor of the nasal cavity. The growths are extensive enough to occupy a significant amount of space, filling the cavity's lumen.
- Stage 4: Polyps reach the nasal vestibule, which is located anteriorly and helps filter out dust and microbes that enter the lungs.
What are the Treatments for Nasal Polyps in Dogs?
The treatments for nasal polyps in dogs are listed below:
- Surgery: Surgery for nasal polyps uses an endoscope, a long tubular apparatus with a camera. Endoscopic surgery removes the nasal polyp and its stalk. The stalk is an important structure that attaches the polyp to the nasal cavity. The polyp is unable to grow back once the tumor and stalk are removed.
- Steroid Nasal Spray: Steroid nasal sprays are available in human medicine to treat nasal polyps. The medication is used for dogs with nasal polyps, although application is difficult for dogs that dislike people touching their muzzle. Nasal sprays contain steroid medication, such as mometasone, that reduces the size of the polyp.
- Oral Steroids: Oral steroids contain medication such as prednisone or prednisolone, which are commonly used for nasal polyps that are not surgically removed. The medication aims to eventually reduce and eliminate nasal polyps through systemic anti-inflammatory action.
- Radiation Therapy: Radiation therapy destroys the DNA in the cells of the abnormal tissue through radiation. The cellular breakdown causes the polyp to regress. Common radiation side effects are alopecia, desquamation dermatitis, skin erythema, ocular discharge, conjunctivitis, decreased tear production, and oral mucositis.
- NSAIDs: Non-steroidal anti-inflammatory drugs (NSAIDs) remove polyps by targeting cyclooxygenase to stop the inflammatory cascade. NSAIDs do not guarantee the regression of nasal polyps, so they are used in conjunction with other forms of treatment. Common NSAIDs used for nasal polyps are meloxicam and piroxicam.
How Much Does It Cost to Remove Nasal Polyps in Dogs?
The cost to remove nasal polyps in dogs is an average of $2,500 for general removal. Costs reach up to $5,000 in some instances. Treatment costs for nasal polyps include veterinary fees for identification, histological examination, pre-operative tests, surgery, and medication. Extensive nasal polyps have a higher price point due to the length of surgery, which affects the usage of anesthesia and other drugs. Numerous polyps in the dog’s nose increase prices further.
How different is Nasal Polyps from Rhinitis in Dogs?
Nasal polyps are different from rhinitis in dogs because nasal polyps are outgrowths of tissue, while rhinitis is an inflammatory disease. Nasal polyps are a consequence of chronic rhinitis. Dog rhinitis is the inflammation of the nasal epithelium due to bacterial, fungal, allergic, or immune-mediated disease. Nasal polyps are abnormal lumps of tissue that grow in the nasal cavity when rhinitis is left untreated. Long-term inflammation predisposes to the occurrence of nasal polyps that interfere with proper breathing and olfaction.