The cat is suspected of having underlying allergic airway disease, although this was not proven. Eosinophils were present in the nasal passages, airways, and blood and are commonly encountered in allergic disease. The mineralized pulmonary nodules seen on thoracic radiographs were thought to be due to dystrophic mineralization of chronically inflamed airways, although granulomas or metastatic disease could not be definitively ruled out.
Interpretation: Multifocal, mineralized, well-circumscribed nodules throughout the lung fields. A diffuse, moderate bronchointerstitial pattern is also present.
Treatment with enrofloxacin PO 5 mg/kg/d was started initially. Again, the cat had a partial response. The mucopurulent nasal discharge resolved, but serous nasal discharge, sneezing, and coughing continued. At this point, corticosteroid therapy was instituted. Systemic corticosteroids were avoided in an attempt to prevent any residual Pseudomonas organisms from causing recurrent infection. Inhalant steroids in the form of fluticasone 220 µg/actuation was chosen, two "puffs" twice daily. Initially, the cat did not tolerate the metered dose inhaler apparatus, so oral prednisone was started at 5 mg PO twice daily. The cat had a dramatic and almost complete response within 2 weeks, after which the prednisone was tapered. The cat gradually began to accept the inhalant steroids and remains on oral prednisone 2.5 mg PO every other day and one "puff" fluticasone once or twice a day when clinical signs worsen. This regimen controls the clinical signs well, and nasal infection has not recurred in 18 months as of this writing.
Did You Answer...
• Sneezing, bilateral mucopurulent nasal discharge with nasal congestion, coughing, tachypnea, lymphopenia, eosinophilia, hyperglobulinemia
• Nasal passages, probably sinuses, trachea, and bronchi
• Resistant bacterial infection, chronic herpesvirus infection, feline asthma bronchitis complex, fungal disease, parasitic disease, and neoplasia (unlikely)
• Nasal radiographs or computed tomography followed by nasal biopsy and deep tissue culture, tracheal wash or bronchoalveolar lavage with cytologic studies and possibly culture