A treatment monitoring protocol to determine clinical remission in dogs with pulmonary coccidioidomycosis

Abstract Background Pulmonary coccidioidomycosis (PC) is a common cause of respiratory tract disease in dogs from endemic regions, but evidence-based guidelines for monitoring treatment and determining remission are lacking. Hypothesis/Objectives Describe temporal changes in clinical signs, antibody serology, and thoracic radiographs in dogs with PC, and evaluate the performance of a treatment monitoring protocol to determine clinical remission. Animals Thirty-one client-owned dogs with newly diagnosed PC. Methods A prospective, cohort study. Dogs were examined at diagnosis (T0) and once every 3 months (T1-T4) until remission or for a maximum of 12 months. Clinical status was assessed using an owner-completed visual analog scale (VAS) representative of the 24 hours and 7 days that preceded the visit. Results The 24-hour and 7-day VAS scores increased (ie, clinical signs improved) from T0 (24-hour: mean, 95% confidence interval CI; 42.3 mm, 35.0-50.2; 7-day: 39.6 mm, 31.9-47.3) to T1 (24-hour, 85.7 mm, 78.1-93.3, 7-day, 84.4 mm, 76.8-92.1, P .001) with minimal change thereafter. Immunoglobulin G titers decreased from T0 (median, interquartile range IQR; 1:16, 1:4-1:32) to T1 (1:2, 1:1-1:8, P .001) without significant changes thereafter. Eighty-four percent (26/31) of dogs achieved remission in a mean of 258.9 days (SD, 108.9), which occurred at T1 (13%, 4/31), T2 (23%, 7/31), T3 (32%, 10/31), and T4 (16%, 5/31). Relapse occurred in 15% (4/26) of dogs. Conclusions and clinical importance Most dogs with PC are expected to achieve remission within 6-9 months of starting antifungal treatment, and relapse is not uncommon.