Nasal Discharge

History

Nasal discharge is almost always a sign of local disease within the nasal cavity. One exception is eosinophilic bronchopneumopathy, an inflammatory condition of the lung and airways that can also involve the nasal epithelium. A second exception can be found in the dog or cat with lower respiratory tract disease (usually bacterial pneumonia) that coughs airway material into the nasopharynx, which subsequently drains from the nose. In both situations, animals usually have a combination of cough and nasal discharge. The most common causes of nasal discharge include infectious, inflammatory, and neoplastic disorders as well as dental-related nasal disease and foreign bodies (Table 1.1). Additional clinical signs that can be seen in animals with nasal disease include sneezing or reverse sneezing, pawing or rubbing at the face, noisy breathing or mouth breathing, facial pain, or an unexplained odor near the head.

Table 1.1. Causes of nasal discharge in dogs and cats

^aReported causes include canine adenovirus-2, canine parainfluenza-3 virus, canine respiratory coronavirus, canine herpesvirus, canine distemper virus, Bordetella and Mycoplasma. Canine influenza virus is a new addition to the list of etiologic agents.

^bReported causes include feline herpesvirus-1, feline calicivirus, Chlamydophila, Bordetella, and Mycoplasma.

When evaluating the animal with nasal discharge, important considerations include the duration of signs, the type of discharge as well as changes in its character over time, and the presence of unilateral or bilateral signs. Acute nasal discharge is often accompanied by sneezing and is most commonly associated with viral upper respiratory tract disease or a foreign body. Animals with acute nasal discharge usually have dramatic clinical signs that either resolve within a week without treatment or are so severe that animals are rapidly evaluated by a veterinarian. More frustrating cases are those with chronic nasal discharge, which often have low level but progressive signs from weeks to months to years before the severity of disease prompts veterinary care.

With many causes of nasal disease including viral disease or foreign body, discharge is serous initially and then progresses to a mucoid character when inflammation induces mucus production or when secondary bacterial infection develops. Yellow-green nasal discharge can be an indicator of eosinophilic disease but is also encountered in other inflammatory conditions, while brown-tinged discharge suggests the presence of blood within the mucus. Bright red blood can be found in combination with nasal discharge because of trauma to blood vessels associated with the primary disease process or due to the severity of sneezing. Pure epistaxis has been associated with local causes of disease, including inflammatory rhinitis, canine aspergillosis, and neoplasia; however, systemic vascular disorders must also be considered including coagulopathies and systemic hypertension.

Nasal discharge that is strictly unilateral is most suspicious for local disease due to a foreign body, trauma, tooth root abscess or oronasal fistula, or an early fungal infection or neoplasm. However, systemic vascular disease or a coagulopathy can result in unilateral signs. Also, inflammatory diseases such as lymphoplasmacytic rhinitis in the dog and feline chronic rhinosinusitis can also present with lateralizing clinical signs, although in most cases, imaging and histology reveal that both sides of the nasal cavity are affected.

Signalment

Young animals with nasal discharge are most often affected by infectious upper respiratory tract diseases. A nasopharyngeal polyp should be considered when discharge is accompanied by obstructed breathing. Primary ciliary dyskinesia is a defect of innate immunity that results in effectual mucociliary clearance, failure to clear secretions, and recurrent infection. Therefore, this condition would be more frequently recognized in a younger animal. Affected dogs are often purebred, with an increased prevalence in the Bichon Frise, although any breed of dog or cat can be affected. While neoplastic disease most typically affects older animals, it also occurs in animals 2–4 years of age and can be particularly aggressive, especially in dogs. Canine aspergillosis is most often encountered in younger dogs and older cats. Cryptococcus and inflammatory rhinitis can affect dogs or cats of any age.

Nasal disease of most types (fungal, neoplastic, and inflammatory) is most commonly found in dolicocephalic dog breeds. An unusual combination of rhinitis and bronchop-neumonia has been reported in the Irish wolfhound, where a genetic defect in respiratory immunity is suspected.

Physical Examination

A complete physical examination is essential in every animal presented for evaluation of respiratory disease. In animals with nasal discharge, important features to focus on include the presence or absence of nasal airflow, changes in ocular retropulsion, lack of soft palate depression, regional local lymph node enlargement, and facial asymmetry or pain. These parts of the physical examination are most important because they can help identify the space-occupying nature of some nasal diseases, particularly nasal neoplasia, feline cryptococcosis, and nasopharyngeal polyps, and because these findings can detect local extension or metastasis.

Nasal airflow can be assessed by holding a chilled microscope in front of each nostril to show fogging of the glass or by using a wisp of cotton (from a cotton ball or Q-tip) to watch for air movement. The mouth should be held closed during the procedure, and occlusion of the alternate nostril can be helpful for enhancing airflow through the side of the nasal cavity to be examined (Figure 1.1). An animal with a mass effect in the nasal cavity or nasopharynx will fail to fog the glass or move the cotton wisp and will often object to this manipulation because it obstructs airflow. Conversely, even animals with heavy mucus accumulation in the nasal cavity will retain nasal airflow.

Facial palpation is performed to assess for a pain response, to locate swellings and depressions in bony structures, and to check for symmetry of the skull. Ocular retropulsion is a part of the facial examination and is performed by placing each thumb over the closed lids and pressing gently backward, upward, medially, and laterally (Figure 1.2). Nasal lesions that are producing a mass effect behind the globe (primarily a neoplasm or retrobulbar abscess) will cause a lateralizing difference in the resistance to depression. Similarly, palpation within the oral cavity can reveal bony abnormalities in the hard palate or might suggest a mass lesion above the soft palate. To perform this examination, the mouth is held open, and the roof of the mouth is palpated from the front of the hard palate through to the end of the soft palate. In the normal animal, the soft palate is readily depressed upward into the nasopharyngeal region (Figure 1.3). A mass in this area (most commonly a neoplasm, fungal granuloma, or polyp) will resist depression. The dental arcade should also be evaluated during the oral examination, although it is important to remember that tooth root disease can be present in the absence of external signs.

Figure 1.1. Nasal airflow can be assessed by occluding one nostril and assessing flow from the alternate nostril with a cotton wisp or chilled microscope slide.

Stay updated, free articles. Join our Telegram channel

Join