Term
Genetic skin disease in dogs and cats: |
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Definition
-Epidermis (ichthyosis)
-Basement membrane zone (lupus)
-Dermis (Ehler’s Danlos, mucinosis)
-Hair follicle (congenital alopecia |
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Term
Normal vs. abnormal Cornification |
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Definition
-modified apoptosis
-70% water loss
-cell interior-keratin fibrils
-cell membrane becomes a cornified envelope
-lipid bilayers
-Statum corneum abnormalities-à altered barrier fxn (loss of integrity, water loss, inflammation and pathogen/allergen entry occurs |
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Term
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Definition
-induces clinical scaling to make more cells/lipid to try to make barrier hydrophobic and repair it which is manifested as clinical scaling
-Primary DOC-anomalies in genes that encode structural proteins or enzymes involved in lipid formation or lipid transport (few tx options, managed but NOT cured)
-Secondary DOC (Vet med term only!)- more than 80% of scaling disorders arise from secondary causes (scabies, adverse food rxn, metabolic dz and endocrinopathy, etc) |
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Term
| ARCI (Autosomal recessive congenital ichthyosis)- name breeds affected |
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Definition
-Golden retriever-PNPLA-1- variable onset age- lipid metabolism defect- generalized white powdery scale, abdominal pigmentation ventrum
-American bulldog-NIPAL-4- scaling from birth-lipid processing enzyme defect/metabolism-v- generalized scaling, red abdomen but not lichenified, pruritic due to Malassezia overgrowth
-JRT (TGM1)- severe cornification defect-lose a lot of water through skin, drink more water and Malassezia overgrowth
-Cavalier king Charles spaniel
-may occur in any breed |
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Term
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Definition
-no treatment
-soak and slather
-address secondary infections (esp American bulldogs) |
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Term
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Definition
-unique hereditary cutaneous lupus in dogs
-affects jxn between epidermis and basement membrane zone and involves basal cell layer and usually immune-mediated
-In humans: 3 categories of lupus (acute, subacute, chronic)
-basal cell vacuolar degeneration +/-apoptosis
+/- mononuclear cell infiltration at dermoepidermal jxn
-melanin that normally resides in keratinocytes falls into dermis (pigmentary incontinence)
-canine cutaneous lupus erythematosus (2 categories: Hereditary and Acquired) |
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Term
Hereditary Canine Cutaneous Lupus erythematosus |
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Definition
-Exfoliative cutaneous lupus erythematosus seen in German short-haired pointer, Magyar vizslas
-Vesciular lupus erythematosus seen in Shelties, Collie and Border Collie |
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Term
-Acquired canine cutaneous lupus erythematosus |
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Definition
-Localized and generalized discoid lupus
-Mucocutaneous lupus
-Systemic lupus erythematosus |
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Term
Exfoliative cutaneous lupus erythematosus |
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Definition
-seen in German short-haired pointer
-affects muzzle, trunk, scrotum, extremities
-scaling, erythema, alopecia, depigmentation, erosions and ulcers
-crouched stance of back
-generalized lymphadenopathy
-shifting leg lameness (arthralgia)
-mild thrombocytopenia/lymphopenia
-hyperproteinemia
-infertility
-FNA L.N.- hyperplasia and plasmacytosis with medullary histiocytosis
-ulcerated scrotums
-Missense variant affecting C-terminal tail of UNC93B1
-50% of dogs euthanized
-managed with corticosteroids, azathioprine and HYDROXYCHLORINE (anti-malarial drug) help slow progression |
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Term
| Skin lesions-non-specific CCLE |
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Definition
-secondary otitis
-superficial pyoderma
-acral pruritic nodules |
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Term
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Definition
-hereditary in Collie, Sheltie and border collie
-Vesicular lupus (aka ulcerative dermatosis)
-Interface rxn with apoptosis of basal keratinocytes with clefting at basement membrane of epidermis and outer root sheath of hair follicle
-drug rxn (EM) may look similar
-adult-onset disease
-calcineurin inhibitors help (oral cyclosporine and topical Tacrolimus)
Familial Dermatomyositis
- “ischemic dermatopathy”
-Juvenile collies and Shelties
-hair loss on muzzle area with scarring alopecia with hypo/hyperpigmentation with erosions
-Skin biopsy needed to differentiate from demodicosis, dermatomyositis, Staph folliculitis
-vascular disease causes ischemic change to skin and causes hair follicle/sebaceous gland atrophy (apocrine glands are spared)
-autosomal dominant and affects young dogs
-Alopecia, scaling and atrophy
-Periocular, muzzle, pinnal margins
-Muscle disease variable
-immune mediated
-vascular injury causes slow ischemic change to skin |
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Term
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Definition
-Histologic diagnosis for group of diseases characterized by inadequate blood and nutrient supply to skin
-common following Rabies vaccine rxn
-Types: 1) Familial Dermatomyositis 2) Dermatomyositis-like 3) Rabies vaccine induced vasculitis with alopecia 4) Vaccine associated ischemic dermatopathy 5) Idiopathic ischemic dermatopathy |
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Term
Treatment of Ischemic dermatopathy |
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Definition
-Pentoxifylline (Methylxanthine derivative)-Vasculopathic disorders- increased microvascular blood flowà increased microvascular blood flow---Increased deformability of rbcs, decreased platelet adhesion, anti-inflammatory properties
-Vitamin E
-Sunscreen
-Glucocorticoids |
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Term
Localized vaccine reaction |
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Definition
-focal area of hair loss and hyperpigmented
-may be severe and lead to nail loss
-nodules, edema in panniculis with adjuvant
-smudging of collagen in dermis, fading follicles |
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Term
-Generalized ischemic dermatopathy |
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Definition
-vasculitis affects ears, muzzle and nasal planum atrophies
-usually close association to vaccine being given
-smaller dogs and older dogs less likely to have vaccine association (idiopathic)
-Poodles more likely to have vaccine association
-immunomodulatory drug management |
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Term
Dermis Components and Function |
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Definition
-Collagen, elastin, proteoglycans
-resident perivascular inflammatory cells (dendritic cells, lymphocytes, mast cells) |
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Term
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Definition
-Inherited disorders of connective tissue
-Wide phenotype-hyperextensible skin to aortic rupture
-Dogs, cats, calves, sheep, cattle
-skin hyperextensibility index increased
-histopathology reveals collagen fibers that are fragmented/disarray and varied in length with large spaces of amorphous eosinophilic matrix
-Multiple genetic variants identified: TNXB, ADAMTS2, COL5A1 |
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Term
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Definition
-Cutaneous asthenia
-Himalyan, Burmese
-Skin hyperelasticity
-Burmese cats develop necrotic eschars
-Normal wound healing
-Not typically lethal
-Collagen changes may be too subtle for light microscopy
-need to know difference and distinguish from acquired skin fragility (seen in older cat due to severe loss of dermal collagen- hair follicles in telogen, due to pituitary tumor or any tumor that leads to excess cortisol or chronic glucocorticoid therapy) |
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Term
Feline acquired skin fragility |
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Definition
-NOT congenital disease, NOT Ehlers Danlos
-Older cats
-Thin skin that tears easily, atrophic scars
-Spontaneous or iatrogenic hyperglucocorticism; diabetes mellitus, hepatic lipidosis, drugs
-profound atrophy of dermal collagen fibers
-prognosis poor |
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Term
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Definition
-Hyaluronic acid (Alcian blue stain)
-Shar pei mucinosis due to increased hyaluronan production
-secondary pyoderma
-excess mucin, vesicles-àrupture |
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Term
Congenital Epidermolysis Bullosa |
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Definition
-(simplex, junctional, dystrophic)
-positive Nikolsky sign
-Congenital
-cannot treat
Acquired Epidermolysis bullosa
-Mucous membrane pemphigoid
-Epidermolysis bullosa acquisita
-can treat with immunosuppressive drugs |
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Term
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Definition
-sloughing pawpads, inguinal region prepuce
-oral cavity ulcers (positive Nikolsky sign)
-epidermis cannot adhere dermis
-stain adherent bottom of cleft
-Plectin mutation-keratin tonofiliments connected to hemidesmosomes (PLEC1 mutation) |
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Term
Junctional EB, Herlitz (horses) |
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Definition
-Aplasia cutis congenita
-pull hooves off skin, clean clefts
-described in Belgian horses |
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Term
| What is the gene mutation for Goldens with icthyosis? |
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Definition
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Term
| What is the gene mutation for American Bulldogs with ichthyosis? |
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Definition
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Term
| What is the gene mutation for ichthyosis in Jack Russell terriers? |
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Definition
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Term
| Which breed of dog is the only reported breed with epidermolytic ichthyosis? |
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Definition
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Term
| What is the genetic mutation for ichthyosis in the Norfolk terrier? |
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Definition
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Term
| What breed of cat has been reported to have a congenital ichthyosis? |
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Definition
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Term
| What white blood cell type is affected in Collies with gray collie syndrome? |
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Definition
| Neutrophils (also called cyclic neutropenia) |
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Term
| Congenital pinnal hyperkeratosis has been recognized in what breed? |
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Definition
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Term
| What treatment was shown to be effective in a French bulldog with congenital pinnal hyperkeratosis? |
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Definition
| Vitamin A controlled the lesions in one month |
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Term
| What breed of dog has a described congenital ectodermal dysplasia-skin fragility syndrome? |
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Definition
| Chesapeake Bay retreivers |
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Term
| A mutation in which important adhesion molecule causes ectodermal dysplasia in Chessies? |
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Definition
Mutation in plankophilin-1
Plankophilin binds to desmocollin/desmoglein to reinforce strength of the desmosome |
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Term
| What breed of dog has the inherited connective tissue disorder Musladin-Lueke syndrome been described in? |
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Definition
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Term
| MLS syndrome in Beagles is characterized by stiff gait/tip-toe stance (joint capsule fibrosis), abnormal facial features and a unique cartilage ear fold. What connective tissue abnormality seems to be the cause of these signs? |
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Definition
A transition of fibroblasts (with excessive TGFb activity- the mutation affects normal TGFb binding sites, so there is too much around)
This leads to a transition of fibroblasts to myofibroblasts and their associated issues (lots of contractility!) |
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Term
| What is the mode of inheritance for DMS in Collies and Shelties? |
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Definition
It is a complex three locus disorder with complicated inheritance. The combination of specific alleles at each locus confers a different level of risk for the disease.
Genetic testing is available. The recent genes identified are PAN2 and MAPK3K7CL. The other strong association is with specific DLA/MCH haplotypes (this is homozygous in most dogs in these breeds) |
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Term
| A mutation in what enzyme is responsible for excessive skin and periodic fever in Shar pei? |
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Definition
| HAS2 (hyaluron synthase 2) |
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Term
| Mutations in what gene are associated with dilute coat color? |
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Definition
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