Lecture 8 2/11/25 Flashcards
(43 cards)
What are the components of every dermatitis?
crusts and scale
What is the presentation of genetic cornification disorders?
-generalized distribution
-diagnosed in young dogs
What are the definitions of crust, scale, and visible scale?
-crust = serum + cells
-scale = keratin
-visible scale = seborrhea
What are the characteristics of normal keratinization?
-keratinocytes are a slowly renewing cell pop.
-migration from basal cell layer to stratum corneum takes around 22 days
-normal desquamation is not visible
What are the characteristics of seborrhea?
-formation of visible scale +/- excess grease
-increased epidermal turnover
-abnormal cornification
-abnormal glandular function
-can be primary or secondary
What are the possible clinical presentations of seborrhea?
-focal or generalized
-mild or severe
-dry, waxy, or greasy
What are the secondary changes seen with seborrhea?
-alopecia
-inflammation
-pruritus
-pyoderma
-lichenification
-hyperpigmentation
-odor
-malassezia colonization
What are the secondary causes of seborrhea/keratinization disorders?
-allergy/other pruritic dermatoses
-external causes such as scabies, lice, and demodicosis
-pyoderma (most common cause)
-endocrinopathies
-pemphigus foliaceus
-epitheliotropic lymphoma
-environmental influences
-nutritional problems
What are the characteristics of primary keratinization disorders?
-hereditary/genetic
-first appear in young animals
-major defect is increased cell renewal time
-often associated with secondary infection
-must rule out secondary causes when attempting to diagnose
What are the steps to diagnosing a primary keratinization disorder?
-rule out infections and secondary causes first
-biopsy; most important tool for diagnosis of primary conditions
Which breeds are affected by primary idiopathic seborrhea?
-cocker spaniels
-springer spaniels
-west highland white terriers
-basset hounds
-setters
-dobermans
-labrador retrievers
-shepherds
-dachshunds
What are the treatment options for primary idiopathic seborrhea?
-vitamin A or retinoids
-fatty acids for seborrhea sicca
-topical antiseborrheic therapy
-cyclosporine
-antibiotics for secondary infections
-malassezia treatment if needed
What is vitamin A-responsive dermatosis most likely to be?
primary seborrhea of cocker spaniels
What are the clinical signs of vitamin A-responsive dermatosis?
-comedones
-follicular fronding or casts
-primarily affects trunk
-follicular seborrhea
How is vitamin-A responsive dermatosis diagnosed?
-histopath. that shows follicular keratoses
-response to treatment
What are the characteristics of genetic zinc-responsive dermatosis?
-seen in huskies and malamutes, can occur in other breeds
-defective zinc absorption
What are the characteristics of zinc-responsive dermatosis in large breed puppies?
occurs with:
-nutritionally poor diet
-diets high in phytates
-diets high in calcium
What is a possible third type of zinc-responsive dermatosis?
dogs with concurrent illness/stress
What is the clinical presentation of zinc-responsive dermatosis?
-alopecia, scaling and crusting of the face, genitalia, and friction points
-foot-pad hyperkeratosis
-secondary infections
-lymphadenopathy
-possible pruritis
How is zinc-responsive dermatosis diagnosed?
biopsy that shows parakeratotic hyperkeratosis and tissue eosinophils
What is the treatment for zinc-responsive dermatosis?
-zinc supplementation
-diet change to one with animal-based protein
-discontinuation of diet supplements
-low dose prednisone if lack of response to zinc alone
What are the characteristics of epidermal dysplasia of west highland white terriers?
-genetic keratinization abnormality
-occurs in dogs less than 1 year of age
What are the clinical signs of epidermal dysplasia of WHWT?
-extreme pruritus
-severe seborrhea
-secondary malassezia and/or pyoderma
-secondary otitis
What are the treatment options for epidermal dysplasia of WHWT?
-treat secondary infections
-try cyclosporine and steroids
-possibly apoquel or cytopoint
-not very rewarding
