Retrospective analysis of the effects of Blastomyces antigen concentration in urine and radiographic findings on survival in dogs with blastomycosis

Abstract

Background: The Blastomyces antigen concentration in urine (BACU) test is used to diagnose blastomycosis and monitor treatment in dogs. It is unknown if a higher BACU is associated with shorter survival. Objectives: To determine if the magnitude of BACU before treatment is associated with survival in dogs with blastomycosis. Animals: Fifty-two dogs with blastomycosis. Methods: Retrospective case review. BACU, radiographic lung severity (RLS) score (0-4 scale), and survival time up to 1 year after diagnosis were obtained through medical record review of dogs with Blastomyces dermatitidis. Results: The overall survival was: discharge, 87%; 1 week, 85%; 2 months, 74%; and 6 months, 69%. BACU correlated with RLS score (r s = 0.33, P = .02). BACU and RLS scores were lower in survivors to 2 months than nonsurvivors (average BACU difference of 2.5 ng/mL, 95% confidence interval [CI]: 0.2-4.8 ng/mL, P = .04; median RLS difference of 2; range, 0-4, P = .02). Dogs with BACU <5 ng/mL and dogs with mild (0-1) RLS scores had a greater proportion surviving than those with BACU >5 ng/mL (P = .03) and dogs with severe (3-4) RLS scores (P = .04). All dogs with a BACU <5 ng/mL or mild RLS score were alive at last follow-up (median, 365 days; range, 44-365 days). In all, 68.1% of other dogs survived to 2 months (95% CI, 54.8%-84.8%). Conclusions and Clinical Importance: Dogs with lower BACU and RLS scores have improved survival; however, it is unclear what specific cutoffs should be used for prognosis.

Case series of dogs with blastomycosis managed with high-flow nasal oxygen therapy (2019–2023): 19 cases

“…The one dog that did survive had a similar clinical presentation to the non-survivors, but the radiographic distribution of its pulmonary lesions was focal rather than diffuse. The proportion of lung affected on radiographs has been demonstrated to predict survival in canine pulmonary blastomycosis ( 8 ). Thus, it is possible the severity of the lung lesions may also predict survival in dogs specifically on HFNOT, but more cases are needed before making that conclusion.…”

“…The overall prognosis for dogs with confirmed Blastomyces infection is generally good (68-75%). However, dogs with severe lung disease have a lower survival rate of 30-60%; other negative prognostic indicators include central nervous system involvement and high band neutrophilia (6)(7)(8)(9). In blastomycosis impacting the patient's ability to oxygenate, the primary treatment, alongside anti-fungal medication, is oxygen therapy (10).…”