Pruritic dog

Question 1

indicators of pruritis

Answer 1

scratching
biting
licking/grooming
chewing
rubbing
head shaking
scooting

Question 2

clinical signs associated with pruritis

Answer 2

erythema (inflammations), alopecia, excoriations, pyotraumatic dermatitis (“hot spots”). With chronicity: also hyperpigmentation, lichenification, acral lick lesions.

Question 3

What the diagnosis/DfDx’s?

• self-induced alopecia
• erythema, sclaing, hyperpigmentation, lichenification
• greasy skin & hair
• malodor
• ears, claw folds, mucocutaneous junctions affected

Answer 3

Malassezia hyper sensitivity

Question 4

Pathophys of Malassezia hypersensitivity

Answer 4

M. pachydermatis is a normal skin commensal -> conditions allow for overgrowth (commonly allergic dermatitis) -> clinical signs

Question 5

Impression smear and tape cytology of greasy skin shows organisms that look like footprints/snowmen/fat bowling pins. What is the Dx/DfDx?

Answer 5

Malassezia

Question 6

treatment of Malassezia hypersensitivity?

Answer 6

Topical:
chlorhex (3-4%),
miconazole

Systemic:
keto-, itra-, flu- conazole (give with food)
Terbinafine

Preventative:
mousse, sprays, medicated wipes, shampoo daily-weekly
Address underlying cause!

Question 7

Sarcoptic mange involves a ____ hypersensitivity

Answer 7

type I - IgE -> degranulation of mast cells & basophils -> allergic reaction that may progress to anaphylaxis

Question 8

• Severe pruritis, not responsive to corticosteroids
• erythema, papules,
• self-induced alopecia
• excoriations, scale, crusts
  Distribution of lesions: ventrum, pressure points, ears, legs.

With chronicity may see:

• lichenification
• generalized lesions
• systemic signs: lethargy, peripheral lymphadenopathy, inappetance

What is Dx/DfDx ?

Answer 8

Sarcoptic mange

Question 9

Hx of contact with wildlife, or having an active outdoor lifestyle.
Marked pruritis, alopecia, erythema, skin lesions.
DfDx?

Answer 9

Sarcoptic mange

Question 10

Treatment for sarcoptic mange/suspected

Answer 10

Selamectin, moxidectin (on label)
ELDU: ivermectin, isoxazolines, isoxazolines

antipruitics (mite die-off can cause increase in hypersensitivity

Question 11

Flea allergy dermatitis can involve which type(s) of hypersensitivity reaction(s)?

Answer 11

type I (allergic, IgE mediated)
type IV (delayed, cell-mediated by T lymphocytes & macrophages)

Question 12

pathophysiology of flea allergy dermatitis/ hypersensitivity dermatitis

Answer 12

fleas -> saliva glycoproteins recognized as antigens -> elicit immune response - Type I or Type IV hypersensitivity

Question 13

Severe pruritis in “pants zone”, over hind limbs, caudal dorsum and bum.
papules
chronic inflammation (erythema, lichenification, hyperpigmentation)
self trauma

Dx/DfDxs?

Answer 13

Flea allergy dermatitis

Question 14

What is a key feature of localization of flea allergy dermatitis?

Answer 14

pants zone!

Question 15

treatment of flea allergy dermatitis

Answer 15

Flea prevention/control

• adulticide with fast speed of kill
• may also use IGR’s but cannot use IGRs alone

topical:
imidacloprid, fipronil, indoxicarb, dinotefuran q 3weeks
imidacloprid collars

systemic: spinosad, nitenpyram,
afoxo-, flu-, saro-laner

Environment: may need to clean carpets; but usually excellent control via the animals is enough