Deep Mycoses

Question 1

Which deep mycoses affect dogs and cats

Answer 1

Cryptococcus
Histoplasmosis capsulatum
Coccioides immitis
Blastomyces dermatidis

Question 2

Which one(s) are lymph node aspirates not useful for?

Answer 2

Blastomycosis

Question 3

Which dogs are predisposed to Blastomycosis

Answer 3

Young, large breed, sporting
Dobie
Lab
Coon dogs
Pointer
Weimaraner

Question 4

Diagnostic tests for blastomycosis

Answer 4

Cytology
Histopathology
Antigen test - dog and human - BAD1 -blood and urine
Antibody test

Question 5

What is the primary route of infection for blastmycosis?

Answer 5

Lungs - inhale conidia which germinate to yeast form

Question 6

What is meant by dimorphic fungus?

Answer 6

Exists in mycelial form in environment and yeast form in tissue

Question 7

How susceptible are dogs to Blastomycosis cf humans?

Answer 7

10 x more susceptible

Question 8

What are risk factors for blastomycosis

Answer 8

Living within 400m water
Outdoor dogs
Sandy and acidic soil
Geographical area eg. N Ammerica - Missouri, Mississippi, Ohio, New York

Question 9

How many dogs have lung lesions with blastomycosis?

Answer 9

85%

Question 10

Is there a seasonal prevalence with Blastomycosis?

Answer 10

Yes, autumn

Question 11

What is the adhesion factor and antigen for blastomycosis?

Answer 11

BAD1

Question 12

How prevalent are skin lesions with blastomycosis?

Answer 12

20 - 50%

Question 13

What are the skin lesions with blastomycosis?

Answer 13

Firm papules, nodules and plaques, ulcers, draining tracts, subcutaneous ulcers

Question 14

Blastomycosis

Answer 14

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

Question 15

Blastomycosis diagnostics

Answer 15

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

Question 16

Blastomycosis treatment

Answer 16

Amphotericin B - but 3 dogs with systemic disease developed calcinosis cutis afetr treatment with amphotericin B
Ketoconazole
Prefer to give sequentially

Question 17

What form of amphotericin B best to treat Blastomycosis and what percentage respond?

Answer 17

Lipid formulation - lower toxicity

83% respond

Question 18

What percentage respond to ketoconazole with blastomycosis?

Answer 18

62%

Question 19

What percentage of dogs have bone lesions with blastomycosis?

Answer 19

30%

Question 20

What percentage of dogs have ocular lesions with blastomycosis?

Answer 20

40%

Question 21

What is the histopathology with blastomycosis?

Answer 21

Nodular to diffuse…….

Question 22

Blastomycosis diagnosis II

Answer 22

Agar gel immunodiffusion (AGID)
Antigen (ELISA) - urine, serum, CSF, and bronchoalveolar fluid - urine best for systemic disease and bronchoalveolar fluid best for pulmonary disease

Question 23

What causes false positives with enzyme immunoassays for Blastomycosis?

Answer 23

Cross-reactions with Histoplasma capsulatum, Crypococcus neoformans and Aspergillus spp