Comparison of histologic lesions of endophthalmitis induced by Blastomyces dermatitidis in untreated and treated dogs: 36 cases (1986-2001).

Abstract

OBJECTIVE:

To compare prevalence of organisms and histologic changes in eyes from dogs with blastomycosis that were either untreated or undergoing treatment with itraconazole.

DESIGN:

Retrospective study.

ANIMALS:

36 dogs with endophthalmitis associated with blastomycosis.

PROCEDURE:

Signalment, results of ophthalmic examination, and duration of treatment with itraconazole were extracted from medical records. Histologic sections from eyes were examined for prevalence and viability (ie, budding) of fungal organisms. A scoring system was devised to assess the degree of inflammation.

RESULTS:

Clinically, all eyes were blind and had signs of severe endophthalmitis. Histologically, the type and degree of inflammation and prevalence of Blastomyces dermatitidis were not significantly different between dogs treated with itraconazole and untreated dogs or among groups of dogs treated for different time periods (4 to 14, 15 to 28, or 29 to 72 days). Replication of the organisms in vascular tissues as well as avascular spaces in the eyes was similar in treated and untreated dogs. Lens rupture was seen in 12 of 29 (41%) eyes.

CONCLUSIONS AND CLINICAL RELEVANCE:

Persistence of inflammation in eyes of dogs with naturally occurring blastomycosis is likely attributable to the continued presence of B. dermatitidis, regardless of the duration of treatment with itraconazole. Lens capsule rupture, a common and previously unreported histologic finding, may contribute to cataract formation and continued inflammation.

• Authors: Diane V H Hendrix, Barton W Rohrbach, Philip N Bochsler, Robert V English
• Journal: Journal of the American Veterinary Medical Association (J Am Vet Med Assoc) Vol. 224 Issue 8 Pg. 1317-22 (Apr 15 2004) ISSN: 0003-1488 [Print] United States
• PMID: 15112782 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antifungal Agents
• Itraconazole

Topics

• Animals
• Antifungal Agents (therapeutic use)
• Blastomyces (isolation & purification)
• Blastomycosis (drug therapy, microbiology, pathology, veterinary)
• Dog Diseases (drug therapy, microbiology, pathology)
• Dogs
• Endophthalmitis (drug therapy, microbiology, pathology, veterinary)
• Female
• Itraconazole (therapeutic use)
• Lens, Crystalline (injuries, microbiology)
• Male
• Retrospective Studies