Records of 70 cases (2004–2016) diagnosed with idiopathic eosinophilic bronchitis (EB) or idiopathic eosinophilic bronchopneumopathy (EBP) were reviewed. Total response (TR) or partial response (PR) was resolution or improvement of clinical signs, respectively. Remission or long-term remission was absence of respiratory signs following discontinuation of therapy for more than one or six months respectively. Relapse was reoccurrence of clinical signs during remission. The following subgroups were established: acute (<1 month of clinical signs) vs chronic (>1 month of clinical signs); EB1 (no radiographic changes or bronchial/peribronchial pattern) vs EBP1 (interstitial/alveolar patterns); EB2 (no radiographic changes) vs EBP2 (any pulmonary pattern); prednisolone dose (<or=1 mg/kg/day; antiinflammatory-A- vs >1 mg/kg/day; immune-mediated-I-). These groups were compared for achievement of remission and long-term remission with chi-square or Fisher's exact test. Probability of achieving remission and long-term remission was evaluated by Kaplan Meier curves/long rank test.

Oral prednisolone was administered to 96% (67/70) of cases (4% received single-inhaled therapy) and 37% (25/67) of those also received combined inhaled fluticasone (no difference between subgroups; p<0.05). Immunosuppressive or antiinflammatory prednisolone was started in 46% (31/67) or 54% (36/67) of cases respectively (no difference between subgroups; p<0.05). In 5% (2/36) of the latter an increase to an immunosuppressive dose to control the clinical signs was required. The 1-, 2-, and 4-year survival to death/euthanasia due to respiratory disease was 95%, 95%, and 91%, respectively. TR and PR occurred in 93% (65/70) and 7% (5/70) of cases respectively. Remission and long-term remission was achieved in 60% (42/70) and 41% (24/58) of cases, respectively. Relapse occurred in 24% (10/42) of cases during remission and in 4% (1/24) during long-term remission. Achievement of TR, PR, remission or long-term remission and the probability of achieving remission or long-term remission was not different (p>0.05) between subgroups although a possible trend towards increased likelihood of achieving long-term remission for the I vs A group was observed.

The conclusions of this study include: Idiopathic eosinophilic lung disease rarely leads to euthanasia or death and clinical response is achieved in all dogs. Unlike the situations in humans we found no evidence that dogs with EB vs EBP or dogs with acute vs chronic disease differ in outcome. Many dogs achieved a total response and remission with anti-inflammatory dose of prednisolone (plus/minus inhaled therapy). However, whether dogs in which an immunosuppressive dose is not used are less likely to achieve long-term remission warrants further studies.

Disclosures

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