Histoplasmosis in a dog from New Brunswick

Area of Science:

• Veterinary Mycology
• Canine Infectious Diseases

Background:

• Histoplasmosis is a systemic fungal infection caused by Histoplasma capsulatum.
• Geographic distribution of Histoplasma capsulatum is typically endemic to specific regions, but cases can occur sporadically.
• Canine histoplasmosis can present with a variety of clinical signs, often affecting the gastrointestinal and respiratory tracts.

Observation:

• A young dog presented with chronic diarrhea, anorexia, and significant weight loss.
• Cytologic examination of lymph node aspirates and peritoneal fluid suggested the presence of Histoplasma capsulatum.
• Clinical signs were consistent with disseminated histoplasmosis.

Findings:

• Fungal culture confirmed the diagnosis of histoplasmosis caused by Histoplasma capsulatum.
• The diagnosis was established through a combination of cytologic findings and definitive fungal culture.
• Diagnostic procedures included fine needle aspirates and fluid analysis.

Implications:

• This case represents the first documented diagnosis of canine histoplasmosis in Atlantic Canada.
• The findings suggest that Histoplasma capsulatum may have a broader geographic prevalence in dogs than previously recognized.
• Veterinarians in Atlantic Canada should consider histoplasmosis in the differential diagnosis for dogs presenting with compatible clinical signs.