Canine Chronic Idiopathic Rhinitis in a Referral Setting

Douglas Palma, DVM, DACVIM (SAIM), The Schwarzman Animal Medical Center, New York, New York

ArticleAugust 20263 min read
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In the Literature

Henry PMN, Rizzo R, Tan Y, Boag AM, Del-Pozo J, Woods GA. Canine chronic idiopathic rhinitis: management and outcome – a single-centre retrospective observational study. J Small Anim Pract. 2026;67(5):460-470. doi:10.1111/jsap.70086

The Research …

Canine chronic idiopathic rhinitis (CCIR), a common and often frustrating cause of chronic nasal signs in dogs, is often lymphoplasmacytic with nonspecific clinical and imaging features.1 Diagnosis requires ruling out other causes via advanced imaging, rhinoscopy, histopathology, and microbiology.

This single-center UK retrospective review described the management and outcome of referral dogs (n = 75) with confirmed CCIR (ie, chronic inflammatory changes on histopathology with no identifiable underlying cause). Median duration of signs before referral was 104 days; most dogs received prior treatment, but only 11 had never been administered antibiotics. CT showed destructive rhinitis in 54 cases.

NSAIDs were the first-line treatment administered most often after referral (46/75 dogs). Multiple trials were needed in most patients and included second-line treatments in 46 cases (antibiotics were most common and administered to 25 dogs), third-line treatments in 25 cases (corticosteroids were most common and administered to 16 dogs), and variable fourth-line treatments in 13 cases. Final outcomes were available for 63 dogs. During the 237-day follow-up period, 22% (14/63) of dogs went into remission, 60% (38/63) were clinically improved, 14% (9/63) were unchanged, and 3% (2/63) worsened. Thirteen dogs died during the follow-up period, 3 of which were euthanized for reasons related to CCIR.

The authors concluded that NSAIDs as first-line therapy were significantly associated with clinical improvement. In addition, therapies varied widely, with frequent antibiotic use despite limited evidence for bacterial involvement.

… The Takeaways

Key pearls to put into practice:

  • NSAIDs are a reasonable first-line treatment option for dogs with suspected or confirmed CCIR.

  • Multiple treatment trials are required in many cases; pet owners should be counseled early on the chronic, variable nature of CCIR, and realistic goals (ie, improvement is common, but full remission is less likely) should be communicated. The role of combination therapy remains unclear, but it may have some clinical utility.

  • Empiric antibiotics should be limited to cases with clear evidence of bacterial involvement, aligning with antimicrobial stewardship principles; most CCIR cases appear noninfectious. The value of routine bacterial cultures in dogs with CCIR is unclear. Inconsistent but occasional clinical response to doxycycline is possible, but whether this is due to reduction in antimicrobial colonization or potential immune-modulating properties is uncertain.2-4

  • Thorough diagnostics (eg, CT, rhinoscopy, histopathology, cultures) should be pursued before long-term therapy is initiated to exclude treatable causes (eg, fungal, dental, neoplasia).

  • Treatment response should be monitored closely and escalated stepwise. Destructive changes on imaging (54 dogs) and periodic epistaxis (13 dogs) in this study did not always predict poor outcome.