To describe signalment, clinical signs, serologic test results, treatment, and outcome of dogs with Coccidioides osteomyelitis (COM) and to compare those findings with findings for dogs with osteosarcoma (OSA).
14 dogs with COM and 16 dogs with OSA.
Data were retrospectively gathered from electronic medical records.
Dogs with COM were younger and weighed less than dogs with OSA. Six dogs with COM had appendicular lesions, 5 had axial lesions, and 3 had both appendicular and axial lesions; 9 had monostotic disease, and 5 had polyostotic disease. Axial lesions and nonadjacent polyostotic disease were more common in dogs with COM than in dogs with OSA, but radiographic appearance was not different between the 2 groups. Median IgG titer at diagnosis of COM was 1:48 and was significantly decreased after 6 and 12 months of treatment. Percentage of dogs with COM that had clinical signs was significantly decreased after 1, 3, 6, and 12 months of treatment. One year after initiation of treatment, 9 of 9 dogs were still receiving fluconazole and 8 of 9 dogs had positive results for serum IgG titer testing.
Dogs with COM typically had a rapid improvement in clinical signs after initiating treatment with fluconazole but required long-term antifungal treatment. Dogs with COM differed from dogs with OSA, but radiographic features had a great degree of overlap between groups, confounding the ability to make a diagnosis on the basis of diagnostic imaging alone.
To characterize the clinical course and therapeutic response in dogs with coccidioidomycosis treated with fluconazole.
49 client-owned dogs with coccidioidomycosis that were treated with fluconazole and had ≥ 2 follow-up examinations.
Medical records were retrospectively searched to identify dogs in which coccidioidomycosis was diagnosed between January 2015 and May 2020. Data recorded from each dog included signalment, clinical signs, diagnostic test results, and treatment.
Dogs were treated with fluconazole at a median initial dosage of 19.7 mg/kg/d. Median treatment duration was 298.5 days, with 26 of the 49 dogs completing treatment during the study period. Respiratory signs, lethargy, and hyporexia were the most common clinical signs. Frequency of lethargy decreased after 30 days, whereas frequency of hyporexia and respiratory signs decreased after 90 days. Median IgG titer at diagnosis was 1:32 and was significantly decreased, compared with baseline titer, at all recheck intervals after 90 days. Hyperglobulinemia, monocytosis, and neutrophilia were the most common clinicopathologic abnormalities. Hyperglobulinemia resolved within 30 days, neutrophilia resolved within 90 days, and monocytosis resolved after 180 days.
Improvements in clinical signs, titers, and clinicopathologic abnormalities were observed after initiation of treatment with fluconazole. Improvement began as early as the first 3 months of treatment, but some variables did not resolve until after 6 to 9 months of treatment. This information provides clinical guidance and describes expectations when prescribing fluconazole to treat coccidioidomycosis in dogs.