Deep Mycoses Flashcards
(23 cards)
Which deep mycoses affect dogs and cats
Cryptococcus
Histoplasmosis capsulatum
Coccioides immitis
Blastomyces dermatidis
Which one(s) are lymph node aspirates not useful for?
Blastomycosis
Which dogs are predisposed to Blastomycosis
Young, large breed, sporting Dobie Lab Coon dogs Pointer Weimaraner
Diagnostic tests for blastomycosis
Cytology
Histopathology
Antigen test - dog and human - BAD1 -blood and urine
Antibody test
What is the primary route of infection for blastmycosis?
Lungs - inhale conidia which germinate to yeast form
What is meant by dimorphic fungus?
Exists in mycelial form in environment and yeast form in tissue
How susceptible are dogs to Blastomycosis cf humans?
10 x more susceptible
What are risk factors for blastomycosis
Living within 400m water
Outdoor dogs
Sandy and acidic soil
Geographical area eg. N Ammerica - Missouri, Mississippi, Ohio, New York
How many dogs have lung lesions with blastomycosis?
85%
Is there a seasonal prevalence with Blastomycosis?
Yes, autumn
What is the adhesion factor and antigen for blastomycosis?
BAD1
How prevalent are skin lesions with blastomycosis?
20 - 50%
What are the skin lesions with blastomycosis?
Firm papules, nodules and plaques, ulcers, draining tracts, subcutaneous ulcers
Blastomycosis
More common in dogs than cats
Non-encapsulated yeast but distinct cell wall
Primary infection usually lungs then disseminates to lymph nodes, ocular, skin, bone, joint, subcut tissue, CNS
If see cut infection then almost always dissem disease
Blastomycosis diagnostics
PAS stain
GMS stain
Capsular antigen ?BAD1 - blood and urine - do both to increase sensitivity; can also use to monitor treatment
Hypercalcaemia of granulomatous disease due to Xs production of 1,25-dihidroxycholecalciferol by macrophages
Hypercoagulability and increased plasma fibrinogen
Culture is gold standard but health and safety concerns
Blastomycosis treatment
Amphotericin B - but 3 dogs with systemic disease developed calcinosis cutis afetr treatment with amphotericin B
Ketoconazole
Prefer to give sequentially
What form of amphotericin B best to treat Blastomycosis and what percentage respond?
Lipid formulation - lower toxicity
83% respond
What percentage respond to ketoconazole with blastomycosis?
62%
What percentage of dogs have bone lesions with blastomycosis?
30%
What percentage of dogs have ocular lesions with blastomycosis?
40%
What is the histopathology with blastomycosis?
Nodular to diffuse…….
Blastomycosis diagnosis II
Agar gel immunodiffusion (AGID)
Antigen (ELISA) - urine, serum, CSF, and bronchoalveolar fluid - urine best for systemic disease and bronchoalveolar fluid best for pulmonary disease
What causes false positives with enzyme immunoassays for Blastomycosis?
Cross-reactions with Histoplasma capsulatum, Crypococcus neoformans and Aspergillus spp
