section name header

Basics ⬇

Basics

Definition

  • Rhinitis-inflammation of nasal epithelium.
  • Sinusitis-inflammation of paranasal sinuses. Includes frontal sinus and maxillary recess in dogs, frontal and sphenopalatine sinuses in cats.
  • The nasal cavity communicates directly with the sinuses; thus rhinitis and sinusitis often occur together (rhinosinusitis).

Pathophysiology

Inflammation and irritation stimulate serous glandular secretion in the nasal mucosa. With chronicity, opportunistic bacterial infections develop in the compromised nasal mucosa causing discharge to become mucoid or mucopurulent. The inflammatory process can lead to turbinate destruction and erosion of the vasculature that results in epistaxis.

Systems Affected

  • Respiratory-sneezing and nasal discharge usually indicate upper respiratory tract disease. Nasal discharge may occasionally be seen with lower airway disease or chronic vomiting disorders
  • Nervous-fungal and neoplastic disease can destroy the cribriform plate and invade the brain.
  • Ocular-epiphora with inflammation or obstruction of the nasolacrimal ducts. Conjunctivitis, keratitis, and/or corneal ulcerations with FHV-1 related disease. Chorioretinitis with canine distemper or Cryptococcus.
  • Oral Cavity-calicivirus, FeLV, FIV are associated with stomatitis, glossitis, faucitis. Tooth root abscess, oronasal fistula or cleft palate possible.

Incidence/Prevalence

  • Primary bacterial rhinosinusitis is rare, secondary infection associated with dental-related disease common.
  • Cats-chronic rhinosinusitis common.
  • Dogs-neoplasia, inflammatory rhinitis (lymphoplasmacytic rhinitis), fungal disease common. Nasal foreign body a cause for acute sneezing.

Signalment

Species

Dog and cat

Breed Predilections

  • Brachycephalic cats more prone to chronic rhinitis and Aspergillus infection.
  • Dolichocephalic dogs more prone to Aspergillus infection and nasal tumors.

Mean Age and Range

  • Cats-acute viral rhinosinusitis and nasopharyngeal polyps more common in young kittens (6–12 weeks).
  • Congenital diseases (cleft palate, ciliary dyskinesia) more common in young animals.
  • Neoplasia and dental disease-older animals.
  • Foreign bodies more common in young dogs.

Predominant Sex

No sex predilection

Signs

Historical Findings

  • Sneezing, nasal discharge, epistaxis.
  • Discharge usually is serous initially and becomes mucoid, mucopurulent, serosanguinous, or hemorrhagic.
  • Unilateral discharge suggests foreign body, tooth root abscess, early neoplasia, or early fungal infection. Idiopathic inflammatory rhinitis can also present with unilateral signs.
  • Bilateral discharge more common with viral or bacterial rhinosinusitis, inflammatory rhinitis, pharyngeal disease, or congenital abnormalities. Chronic presentation of neoplasia or fungal rhinitis is often bilateral.
  • Facial deformity or facial pain-usually with fungal or neoplastic disease.
  • Reverse sneezing more common in dogs, inappetence more common in cats.

Physical Examination Findings

  • Check for decreased nasal air flow, bilateral or unilateral, which would suggest an obstructive mass lesion.
  • Evaluate oral cavity for tooth root abscess, oronasal fistula, cleft palate or ulcers.
  • Increased tracheal sensitivity or cough possible with lower airway causes of nasal signs.
  • Look for epiphora, conjunctivitis. Horner's syndrome can be seen with middle ear disease.
  • Fundic examination-chorioretinitis possible with infectious diseases; hypertension can result in tortuous retinal vessls or hemorrhage, platelet abnormalities can be associated with retinal hemorrhage or petechiation.

Causes

Dogs

Primary Inciting Causes

  • Fungal disease-Aspergillus fumigatus most common. Penicillium spp., Rhinosporidium seeberi, Blastomycoses dermatitidis, Cryptococcus neoformans are rare causes.
  • Tooth root abscess.
  • Foreign body.
  • Congenital abnormalities such as cleft palate or primary ciliary dyskinesia.
  • Parasitic causes-nasal mites (Pneumonyssoides caninum), Capillaria aerophila, Eucoleus boehmii.
  • Intranasal neoplasia-adenocarcinoma most common (31.5%). Others include lymphoma, chondrosarcomas, or osteosarcomas.
  • Immune-mediated rhinitis-allergic rhinitis rare, idiopathic lymphoplasmacytic rhinitis more common.
  • Other infectious diseases include canine distemper or Bordetella bronchiseptica; Bartonella not associated with rhinitis.
  • Local trauma can cause bone or turbinate deformity and predispose to chronic rhinitis or Aspergillus infection.

Secondary Causes

  • Lower airway disease (bronchopneumonia) or vomiting can result in nasal signs through nasopharyngeal regurgitation. .
  • Nasal discharge can occur with eosinophilic bronchopneumopathy.
  • Epistaxis can be related to hypertension, thrombocytopenia, thrombocytopathia, or rarely other coagulopathies; trauma or foreign body also possible.

Cats

Primary Inciting Causes

  • Viral infections-feline herpesvirus-1 and calicivirus account for 90% of acute infections in kittens.
  • Bacteria-Bordetella bronchiseptica can be a primary pathogen in cats but its significance is uncertain. Bartonella not associated.
  • Neoplasia-adenocarcinoma and lymphoma most common.
  • Fungal disease-Cryptococcus neoformans most common, Aspergillus felis, Penicillium (rare).
  • Nasopharyngeal polyps in young cats>dogs.
  • Nasopharyngeal webbing/stenosis-congenital or secondary to chronic infection or inflammation.
  • Tooth root abscess or oronasal fistula.
  • Foreign bodies.
  • Congenital abnormalities include cleft palate.

Secondary Causes

  • Epistaxis due to coagulopathy or hypertension.
  • Aspiration of vomitus into the nasopharynx

Risk Factors

  • Dolichocephalic breeds-fungal disease
  • Brachycephalic cats-rhinosinusitis

Diagnosis ⬆ ⬇

Diagnosis

Differential Diagnosis

Rule-out secondary causes of rhinitis including coagulopathy, hypertension, lower airway disease, chronic vomition.

CBC/Biochemistry/Urinalysis

  • Hemogram is nonspecific-may show leukocytosis (neutrophilia or eosinophilia) with infectious agents. Regenerative anemia with severe blood loss from coagulopathy. Nonregenerative anemia with chronic disease or neoplasia. Thrombocytopenia seen with coagulopathies or severe blood loss.
  • Serum biochemistry and urinalysis typically normal.

Other Laboratory Tests

  • FeLV and FIV serologic tests
  • Latex agglutination test for cryptococcal capsular antigen
  • Aspergillus titers: AGID in dogs-false negatives possible, false positives uncommon. ELISA in cats (research tool currently)-high sensitivity and specificity for disease
  • Coagulation profile-if epistaxis present

Imaging

  • Radiography-chest radiographs if lower airway disease or neoplasia suspected.
  • Dental radiographs highly sensitive for detecting periodontal disease.
  • Skull radiographs are useful but do not differentiate among inflammatory rhinitis, fungal infection, and neoplastic disease. Loss of turbinate structures can be seen with all causes. Open-mouth or intraoral ventrodorsal views provide superior evaluation of the nasal cavity and avoid superimposition of the mandible.
  • Nasopharyngeal polyps occasionally seen within the nasopharynx.
  • CT/MRI-superior to plain radiography in evaluating the extent of disease and assessing the integrity of the cribriform plate. Also useful in evaluating disease of the palate, nasopharyngeal meatus, maxillary sinus, periorbital tissues, middle ear canal.

Diagnostic Procedures

Arterial Blood Pressure

  • Evaluate for hypertension if epistaxis.

Lymph Node Aspirate

  • Can be diagnostic for neoplasia or Cryptococcus.

Cytology

  • Nasal swab may reveal Cryptococcus.

Culture

  • Usefulness of culture is controversial-most animals have secondary bacterial infection. Potential bacterial pathogens are more commonly isolated in cats with rhinosinusitis than healthy cats.
  • Fungal culture of a plaque lesion visualized on endoscopy aids in diagnosis of aspergillosis. Blindly collected specimen less likely to be useful.
  • Asymptomatic intranasal carriage of Cryptococcus possible.

Endoscopy

  • An otoscope evaluates only the rostral nasal cavity. A rigid endoscope can be guided to the ethmoid turbinates, flexible endoscope provides good visualization rostrally, and can be retroflexed in the nasopharynx to visualize the caudal choanae.
  • Guided biopsy is possible with rigid and flexible endoscopy. Other techniques include core or blind pinch biopsies. Excessive hemorrhage can be controlled with topical epinephrine at 1:100,000.

Surgery

  • Exploratory rhinotomy most invasive diagnostic tool, can be required for difficult foreign body or mass removal, if endoscopy is unsuccessful. Rarely required to obtain a definitive biopsy sample.

Pathologic Findings

Chronic inflammation causes turbinate resorption, mucosal ulceration and necrosis. Lymphoplasmacytic infiltrate indicates chronicity, neutrophilic usually signifies acute component. Neoplasia and fungus also cause bony lysis or destruction.

Treatment ⬆ ⬇

Treatment

Nursing Care

Humidification can aid in moistening and mobilizing nasal secretions. Saline intranasal drops helpful if tolerated. Keep nares clean of obstructive mucus.

Client Education

Signs of chronic rhinitis can be variably controlled but are rarely eliminated.

Surgical Considerations

  • Rhinotomy is reserved for obtaining a biopsy or foreign body/mass removal when endoscopic intervention is unsuccessful. Rarely provides an advantage over endoscopy.
  • Surgery useful for polyp removal, dental-related nasal disease (tooth root abscess, oronasal fistula, cleft palate).

Medications ⬆ ⬇

Medications

Drug(s)

Antibiotics

Antibiotics help control secondary bacterial rhinitis; however, they will not resolve disease. Selection of antibiotic is mainly empirical (common isolates include Staphylococcus, Streptococcus, Bacillus, E. coli, and Pasturella multocida). Long-term use often needed.

Antifungals

See Cryptococcosis and Aspergillosis chapters for detailed treatment discussion.

L-lysine

Inhibits FHV-1 replication; may be useful-250 (kitten)–500 (cat) mg PO q12h.

Anti-inflammatory Agents

Piroxicam (nonsteroidal anti-inflammatory agent) used for palliation of nasal tumors (via COX-2 inhibition), either as sole agent or in conjunction with chemotherapy. Sometimes helpful in animals with rhinitis.

Steroids

Consider use with chronic rhinosinusitis in cats or lymphoplasmacytic rhinitis in dogs at anti-inflammatory doses when mucus obstruction limits appetite.

Antihistamines

Efficacy is debated

Anti-parasitics

Ivermectin 300 µg/kg PO or SC once weekly for 3–4 treatments or milbemycin oxime 1 mg/kg PO once weekly for 3 weeks for treatment of nasal mites.

Contraindications

Avoid chronic steroid use owing to danger of immunosuppression.

Precautions

  • NSAIDs can cause GI ulceration.
  • Tetracycline may stain teeth of young animals.

Possible Interactions

Use of NSAIDs and corticosteroids together is contraindicated.

Follow-Up ⬆ ⬇

Follow-Up

Prevention/Avoidance

Vaccinations in kittens can lessen severity and duration of viral infection.

Possible Complications

  • Extension of fungal or neoplastic invasion into brain.
  • Seizures and other neurologic signs are possible if topical antifungal therapy is used when the cribriform plate is not intact.

Expected Course and Prognosis

  • Dependent on etiology and extent of disease.
  • Acute viral/bacterial rhinitis-good prognosis, chronic rhinitis-guarded for control of signs.
  • Fungal-fair to guarded prognosis depending on invasiveness and response to therapy.
  • Neoplastic-3–5 months with no treatment. Life expectancy can be extended up to 9–23 months with radiation therapy.

Miscellaneous ⬆

Miscellaneous

Zoonotic Potential

Cryptococcus, Aspergillus, Penicillium are transmissible to humans via shared environment. No direct transmission.

Abbreviations

  • CT = computed tomography
  • FeLV = feline leukemia virus
  • FHV = feline herpesvirus
  • FIV = feline immunodeficiency virus
  • GI = gastrointestinal
  • MRI = magnetic resonance imaging
  • NSAID = nonsteroidal anti-inflammatory drug

Authors Carrie J. Miller and Lynelle R. Johnson

Consulting Editor Lynelle R. Johnson

Client Education Handout Available Online

Suggested Reading

Johnson LR, Foley JE, De Cock HE, et al. Assessment of infectious organisms associated with chronic rhinosinusitis in cats. J Am Vet Med Assoc 2005, 227(4):579–585.

Russo M, Lamb CR, Jakovljevic S. Distinguishing rhinitis and nasal neoplasia by radiography. Vet Radiol Ultrasound 2000, 41(2):118–124.