Dogs with long noses and skulls are most commonly affected such as the Collie, Border Collie, Australian Shepherd, Shetland Sheepdog and Greyhound. Conversely, brachycephalic breeds (such as the French Bulldog, English Bulldog, Pug and Boxer) are prone to pollution-induced tumors that can cause rhinitis.

Rhinitis and sinusitis are closely related afflictions. Both refer to swelling; sinusitis refers specifically to the swelling of nasal passages while rhinitis refers to swelling of the nose. 

Acute 

This is generally caused by a foreign body lodged in the dog’s nasal cavity. In this case, sudden and violent sneezing will likely be the first apparent symptom.

This occurs when the cause of rhinitis cannot be definitely diagnosed. Most often it is seen with allergies that can not be eradicated from the dog’s living space (such as grass). Chronic rhinitis also happens when the dog suffers from acute viral infections or when a bad tooth is exacerbating the problem.

Rhinitis can occur for many reasons. The most prevalent cause is a viral infection. Parainfluenza virus, herpesvirus, and adenovirus are the most widespread.  Although bacterial infections are often a factor, a bacterial infection alone does not usually cause rhinitis. Canine distemper is a somewhat common cause. Bordetella is a less common cause. If your dog goes to daycare, even if he has been vaccinated for bordetella as most kennels require, this could still be a cause. The bordetella vaccine is not 100% effective. In general, dogs who are vaccinated against bordetella have less severe symptoms and a shorter recovery time. Other causes include:

If clinical signs are present, your dog should be considered as having rhinitis and sinusitis. Nasal discharge, facial pain, and eye redness may indicate the condition. Because rhinitis can be caused by a variety of reasons it can prove difficult to effectively diagnose and treat. Your veterinarian will need to take blood samples and do laboratory tests such as a nasal culture or tissue biopsy. Your veterinarian will want to rule out underlying possible causes like neoplasia, or effectively treat infections causing the rhinitis or sinusitis, such as fungal invasion. In the event of a foreign body or tumor causing rhinitis, an x-ray will be needed to diagnose. CT scans may provide additional views; in the case of parasites, sometimes a nasal flush is used.

Treatment of rhinitis and sinusitis varies widely depending on the cause. Surgery may be needed in the case of a foreign body lodged in the nose or for removal of a tumor or in the case of trauma. Dental complications may require the removal of the guilty tooth. Antibiotics are widely used in the case of bacterial infections. Fungicides may also be used. Many dogs will require IV fluids if the infection is severe and a high fever is present. 

In mild or acute cases, supportive care may be enough treatment. In the case of viral infections, a secondary bacterial infection can develop. In this case, the viral infection is typically treated with supportive care and antibiotics are used to treat the secondary infection. 

Lysine is an essential amino acid that helps your dog’s body produce antibodies, hormones, and enzymes that boost the immune system. In the case of a chronic viral infection, lysine can be an effective addition to supportive care. Functional treats are available with lysine.

Your pet may need a medication protocol during his recovery. Anti-inflammatories, antibiotics, and additional amino acids may be necessary as prescribed by the veterinarian.

Prognosis varies depending on the age of the dog, cause, and severity of the case. Many cases respond well to treatment. Some become chronic. Generally speaking, the sooner diagnosis can be made, the better the dog responds to treatment. In cases of chronic rhinitis, pet parent and veterinarians will need to work together to maintain effective treatment.