L1-congenital, epidermal differntiation, and pigmentation disorders

Question 1

epidermis

Answer 1

stratified squamous.

Question 2

Dermis

Answer 2

Adnexa-hair follicles

Question 3

subcutis

Answer 3

adipose tissue- hypodermis

Question 4

congenital

Answer 4

present at birth- not all are hereditary

Question 5

hereditary

Answer 5

not always present at birth
EX: color dilution alopecia
not all are congenital

Question 6

Ichthyosis

Answer 6

hereditary/ inherited
various dogs, cattle
known genetic mutation in some dog breeds
defects in formation of statum corneum
scaling and thickened skin
diagnosis: skin biopsy

Question 7

Ichthyosis fetalis

Answer 7

cattle: more severe, still born cattle

Question 8

ichthyosis congenita

Answer 8

cattle: not as severe

Question 9

Epidermolysis bullosa

Answer 9

red foot disease
defects in the basement membrane of the epidermis
defect in proteins between dermis and epidermis
clefts and vesicles where epidermis meets dermis
skin and mucous membrane blistering and ulceration from minor trauma
oral mucosa, lips and extremities
hooves, pads, claws can slough off
cattle, sheep, goats, horses, dogs

Question 10

Epitheliogenesis imperfecta

Answer 10

Aplasia cutis
failure of statified squamous epithelium to completely develop
sharply demarcated areas without epidermis
face, extremities, mucous membranes

Question 11

Hereditary Zinc deficiency

Answer 11

occurs in cattle and bull terrier dogs
autosomal recessive- hereditary
multi-systemic disease with skin lesions
crusting mainly on face and distal limbs with dry, flaky skin

Question 12

Hereditary zinc deficiency in cattle

Answer 12

lethal trait A46; defect in intestinal malabsorption
die due to immune dysfunction, thymic hypoplasia- more prone to infection

Question 13

hereditary zinc deficiency in dogs

Answer 13

lethal acrodermatitis of bull terriers
doesn’t respond to supplementation

Question 14

Hereditary zinc deficiency on biopsy

Answer 14

diffuse parakeratotic hyperkeratosis

Question 15

Hereditary zinc deficiency image

Answer 15

Question 16

congenital hypotrichosis/alopecia

Answer 16

lack of hair where it should be present
reported in many domestic animal species
most common in calves
can be purposely bred- chinese crested, mexican hairless pig, sphix
need to distinguish form non-genetic causes
maternal iodine deficiency
intrauterine infection with bovine viral diarrhea or classical swine fever
samples: most alopecic and most haired from similar anatomic locations

Question 17

congenital hypotrichosis/ alopecia

Answer 17

Question 18

Hypertrichosis

Answer 18

excessive amount of hair
-rare
cattle friesian cattle, hereditary
lambs- border disease infection in utero
hairy shaker disease
long, course hair and clonic- tonic spasms of tremors

Question 19

Dermatomyositis

Answer 19

disease of dogs
hereditary in collies, shelties
pathogenesis is unknown
idiopathic inflammatory disease of skin and muscle

Question 20

Dermatomyositis

Answer 20

ischemic dermatopathy
small pustules, and vesicles, progress to ulcerations with alopecia
eventual scarring
pinnae, bridge of nose, lips, periocular skin, tip of tail
likes to target face and capillary walls

Question 21

Hereditary collagen dysplasia

Answer 21

dermatospraxis, ehlers-danlos syndrome, cutaneous asthenia
reported in most domestic animals-rare
skin stretches and tears easily
defect in enzymes involved in collagen synthesis or processing
skin tears easily and is hyperestensible/loose
minimal hemorrhage

Question 22

Hereditary collagen dysplasia

Answer 22

HERDA- hereditary equine regional dermal asthenia
hereditary in quarter horses- especially elite cutting horse lines
genetic test availabe

Question 23

Dermatosis vegetans

Answer 23

inherited disease of pigs
Landrance breed
vegetating skin lesions, hoof malformations, giant-cell pneumonia
start on ventral abdomen and medial thighs-expand to cover all skin
erythematous papules- crusty lesions with a brown-black color and central depression
if pigs survive, lesions start to resolve

Question 24

Epidermal differentiation

Answer 24

top layer of skin/ satisfied squamous

Question 25

Keratoses

Answer 25

firm, elevated areas of excessive keratin production

Question 26

Equine linear alopecia- linear keratosis

Answer 26

many breeds, quarter horses predisposed vertically oriented linear areas of alopecia, crust and scaling shoulder, neck lateral thorax

Question 27

Equine cannon keratosis-stud crud

Answer 27

vertically oriented areas of alopecia, scaling, and crusting on cranial surface of rear cannon bones not itchy or painful

Question 28

Sebaceous Adenitis

Answer 28

disease of dogs standard poodle is predisposed destruction and loss of sebaceous glands around hair follicles - antimicrobial protection symmetrical alopecia with broken hairs brown to yellow follicular casts often have secondary bacterial infection

Question 29

Vitamin A responsive dermatoses

Answer 29

Nearly exclusively in cocker spaniels not a true vitamin A deficiency levels normal Does NoT respond to vitamin A treatment - Hyperkeratotic plaques with follicular externa plugging on ventral and lateral chest and abdomen • Greasy hair coat with ceruminous otitis

Question 30

Exfoliative dermatoses

Answer 30

lots of scaling, crusting, and erythema can be localized or generalized usually associated with another disease thymoma, epitheliotropic lymphoma, drug reactions

Question 31

Hyperplastic dermatosis of Westies

Answer 31

West highland white terriers SEVERE skin disorder, usually a manifestation of allergic skin disease erythema, scaling, pruritus-trunk, axillary and inguinal regions chronic cases- skin becomes lichenified, hyperpigmented -armadillo westie syndrome

Question 32

Equine coronary band dystrophy

Answer 32

proliferation and hyperkeratosis of epidermis of coronary band- thickened chestnut and ergots can also be affected coronary band is thicked -crusting, scaling hoof wall often abnormal

Question 33

Pigmentary disorders

Answer 33

disorder of melanin

Question 34

Melanin

Answer 34

synthesized by melanocytes requires tyrosine and tyrosinase- rate limiting enzyme, critical also require copper- deficient/ then deficient in ability to produce melanin pigment after production, melanin transferred to nearby epidermal cells

Question 35

melanosomes

Answer 35

membrane bound organelles that make melanin within melanocyte

Question 36

Leukoderma

Answer 36

reduced pigment in skin

Question 37

Leukotrichia

Answer 37

reduced pigment in hair

Question 38

Focal macular melanosis

Answer 38

lentigo simplex seen in dogs and cats especially cats that are orange, cream and tri colored flat, pigmented macules, usually on mucocutaneous junctions of mouth, eye, nose and footpads clinically insignificant, can be confused for melanoma sheep- can be seen after sheering

Question 39

Canine acanthosis nigricans

Answer 39

progressive alopecia, hyperpigmentation, and lichenification of the skin idiopathic disease, progressive dachshunds are predisposed - early age of onset start in axilla, spread to ventral abdomen and inguinal areas often have secondary bacterial or yeast infections

Question 40

Acromelanism

Answer 40

Temporary coat color change due to temperature high temp-light color low temp- dark color cats- siamese and himalayan rabbits and mice

Question 41

Hereditary hypopigmentation disorders - Melanocytopenic hypomelanosis

Answer 41

similar to waardenburg syndrome in people white coats , blue or heterochromatic irises, and are deaf

Question 42

Vitiligo

Answer 42

biggest one seen clinically progessively expanding pale macules, often symmetrical

Question 43

Cyclic hematopoiesis- grey collie syndrome

Answer 43

silver grey hair coat also causes cyclic neutropenia

Question 44

Acquired hypopigmentation

Answer 44

-usually secondary to something secondary to trauma, radiation, infection, nutritional deficiences horses- onchocerca, culicoides, coital vesicular exanthema

Question 45

canine uveodermatologic syndrome

Answer 45

artic breeds- akita, husky, malamute bilateral panuveitis and bilateral cutaneous depigmentation lips nose periorbital skin- clinically relevant

Question 46

Hereditary cutaneous Hylaluronsis

Answer 46

Cutaneous mucinosis • Inherited dermal connective tissue disorder • Hyaluronic acid is main component • Overactivation of hyaluronan synthase 2 à large amounts in dermis • Chinese Shar-Pei dog • Wrinkled skin appearance • Also seen secondary to hypothyroidism • Myxedema in dermis

Question 47

Hereditary cutaneous hyaluronsis

Answer 47

Cutaneous mucinosis • Inherited dermal connective tissue disorder • Hyaluronic acid is main component • Overactivation of hyaluronan synthase 2 à large amounts in dermis • Chinese Shar-Pei dog • Wrinkled skin appearance • Also seen secondary to hypothyroidism • Myxedema in dermis