Dermatophytosis

Question 1

most common dermatophytes in dogs and cats

and their reservoir?

Answer 1

m. canis (cats)
m. gypseum (soil)
trichophyton mentagrophytes(rodents)
(all live in follicle)

Question 2

dermatophytes in horses, cattle pigs?

Answer 2

horse - t. equinum
cattle - t. verrucosum
pigs - m. nanum

Question 3

predisposing factors to dermatophytosis

Answer 3

decreased grooming, microtrauma, excessive hydration, warm temperature/humidity, lack of exposure to sun, strong cell-mediated immunity
(breach in skin)

Question 4

dermatophytosis signalment

Answer 4

• white persians and himalayans (asymtomatic carriers and susceptible) and terriers
• young, sick, emaciated animals predisposed

Question 5

clinical signs of dermatophytosis

Answer 5

• alopecia most common
• crusting, scaling, pustules
• pruritis variable (more in not dogs)
• cats - miliary dermatitis, nodules, plaques (generally muzzles and feet)
• well demarcated alopecia*

Question 6

naso-planum does/does not ? have follicles?

gets affected by dermatophytes?

Answer 6

no, no! usually spared because the common dermatophytes are follicular

Question 7

presentation in horses

Answer 7

ulcers, follicular pustules, highly pruritic
trunk most affected (saddle tack regions)
variable annular allopecia

Question 8

cattle dermatophytosis

Answer 8

annular alopecia on head/neck

variable pruritis

Question 9

kerion

Answer 9

well circumscribed nodular mass
generally on head or feet
happens when a breach of follicle (furunculosis with fungi in dermis)

Question 10

diagnosis of dermatophytosis

Answer 10

1. woods lamp exam (only a positive helps, 50% of m. canis) need to have hair follicle fluoresce!
2. trichogram (distorted hair shaft and spores)
3. culture

Question 11

healthy animals can self cure in _____ months, but…?

Answer 11

3-4months

but theyll be spreading spores to humans so we treat!

Question 12

treatment dermatophyte

Answer 12

• topical (ketoconazole,miconazole, chlorhex with an antifungal, lyme sulfur)
  +/- clip hair for remove spores (but doesnt create more lesions!)
• rinses (lyme, enilconazole)
• mousse with climbazole (can be used for local area just not alone)
• systemic (ketoconazole, itraconazole, fluconazole, terbinafine, griseofulvin)

Question 13

griseofulvin

Answer 13

• old very cheap
• only for dermatophytes
• many side effects (so not used anymore much)

Question 14

ketoconazole

Answer 14

most common
- all dermatophytes and yeast
inhibit p450, can induce anorexia in cats

Question 15

itraconazole

Answer 15

2nd most common agianst dermatophytes
safer than ketoconazole(less p450 inhibition), preferred for cats. accumulates in keratinized tissue
$$

Question 16

fluconazole

Answer 16

safest among the three azoles!

Question 17

all azoles are

Answer 17

fungistatic

Question 18

terbinafine

Answer 18

fungicidal
few side effects (no inhibition of p450)
accumulates in keratinized tissues

Question 19

duration of therapy

Answer 19

2 negative cultures 1 month apart

treat all animals in house