Chapter 12 - Congenital/Hereditary Flashcards
Name two breeds in which primary seborrhoea is most commonly recognised
American Cocker
English Springer
WHWT
Basset Hound
What is the epidermal renewal time in seborrheic Cockers?
8 days (21 = normal)
Which anatomical sites show the most severe signs with primary seborrhoea?
Periocular, perioral, pinnae, intertiginous areas of feet, axillae and groin
Which breeds show a dry, flaky phenotype of seborrhoea?
Irish Setters and Dobermans
With the greasy phenotype of seborrhoea, which anatomical sites show dry, flaky skin?
Caudodorsum
Shampoos containing which products are suitable for more severe flaky scaling?
Sulfur and salicylic acid
Which condition can occur with long term use of retinoids?
KCS
Calcitrol therapy can decrease which hormone level?
Parathyroid hormone
What effect do steroids have on dogs with greasy seborrhoea?
Atrophic effect on the epidermis and sebaceous glands
Primary seborrhoea has been recognised in which breeds of cat?
Persian
Himalayan
Exotic short hair
What is the epidermal renewal time with ichthyosis?
3.6 days
In golden retrievers, which epidermal structure is abnormally retained with ichthyosis?
Corneodesmosomes
Which keratin is reduced in the epidermis of Norfolk terriers with ichthyosis?
Keratin 10
Which breed of dog may not show signs of ichthyosis at birth?
Golden retrievers
Which breed of dog can develop blisters and erosions with mild skin trauma with ichthyosis?
Norfolk Terriers
With ichthyosis, is the hyperkeratosis ortho- or para-keratotic?
Orthokeratotic
How long can it take to see a response to retinoid treatment of ichthyosis?
Up to 6 months
What is the difference in clinical distribution of signs between ichthyosis and follicular parakeratosis?
Nasal planum and footpads are not affected in follicular parakeratosis and there is minimal involvement of glabrous skin
What abnormality is seen on histopathology of follicular parakeratosis?
Lipid vacuoles in the debris and keratinocytes in the follicular epidermis
Orthokeratotis basket-weave hyperkeratosis
Epidermal dysplasia in WHWT is associated with which microbe?
Malassezia
Which anatomical site is affected in schnauzer comedo syndrome and which type of schnauzer is affected?
Dorsum
Miniature
What are the 3 categories of the inherited form of epidermolysis bullosa?
Epidermolysis bullosa simplex
Junctional epidermolysis bullosa
Dystrophic epidermolysis bullosa
Where do clefts form with epidermolysis bullosa simplex?
Basal layer of the epidermis
Where do clefts form with junctional epidermolysis bullosa?
Lamina lucida of basement membrane zone
Where do clefts form with dystrophic epidermolysis bullosa?
Below the lamina densa
Name two breeds of dog, bar collies and shelties, affected by familial dermatomyositis
Beauceron shepherd Belgian Tervurens Portugese water dogs Corgi Lakeland terrier Chow GSD Kuvasz
Define anychoschizia
Splitting of nails
What are the cutaneous histopathology findings in dermatomyositis?
Scattered hydropic degeneration of the surface and follicular basal cells with occasional apoptosis of basel cells +/- intrabasal or subepidermal clefts
Darrier disease in English setters is associated with abnormal homeostasis of which mineral?
Calcium (due to depletion of SERCA2-gated stores)
Also reported in an Irish Terrier
Define trichoptilosis
Longitudinal splitting of the distal end of the hair
Medullary trichomalacia typically affects which breed?
GSDs
Which hairs are affected in shaft disorder of Abyssinian cats?
Whiskers and primary hairs
Which hairless dog breeds have ectodermal dysplasia?
Mexican hairless and Chinese crested
In black hair follicle dysplasia, by what age does near total alopecia occur?
6-9 months (starts from 4 weeks)
What distribution of pattern baldness in dachshunds is more common in females than males?
Pre- and post-auricular, ventral neck, ventrum and caudomedial thighs
Where does the genetic mutation occur in colour dilution alopecia?
MLPH (melanophilin) gene (SNP/insertion)
Same gene is affected in black hair follicle dysplasia!
What are the late stage follicular changes in colour dilution alopecia?
Dilated, cystic follicles
Which breed is typically affected by follicular lipidosis?
Rottweiler
What presenting sign of follicular lipidosis is pathognomic?
Hair loss restricted to the mahogany points of the face and feet
Axillary hyperpigmentation, lichenification and alopecia is seen with which disorder?
Acanthosis nigricans
Which breed is affected by acanthosis nigricans?
Dachshund
In which breeds/species have cases of Chediak-Higashi syndrome been reported?
Persian cats White tigers Hereford cattle Aleution mink Humans
Chediak-Higashi syndrome is associated with which coat colour in Persians?
Blue-smoke with yellow eyes
What are the clinical signs of Chediak-Higashi syndrome?
Increased susceptibility to infection, partial oculocutaneous albinism, photophobia, bleeding disorders and large eosinophilic granules in neutrophils and macrophages on blood smears (lysosomes)
Canine cyclic haematopoiesis is associated with a mutation of which gene?
APB3
Acquired aurotrichia occurs in which breed of dog?
Min. Schnauzers
What are the clinical signs and course of aurotrichia?
Gold coloured hair on the dorsum (+/- periocular skin and ears) that spontaneously resolves in 6-24 months
In cutaneous aesthenia, collagen forms which shape instead of normal cylindrical fibrils?
Twisted ribbons
In cutaneous aesthenia, decreased activity of procollagen peptidase leads to lack of cleavage of what from type 1 procollagen?
N-terminal propeptides
In cutaneous aesthenia, how is wound healing affected?
It can be normal but leaves thin, white scars.
In cutaneous aesthenia, what is the extensibility index in affected dogs and cats?
14.5% dogs
19% cats
In cutaneous aesthenia, which supplement can be beneficial in dogs?
Vitamin C
Multiple collagenous nevi are a marker for which systemic disease?
Renal cystadenocarcinomas or uterine leiomyomas
Acrodermatitis is reported in which breed of dog?
Bull terriers
In acrodermatitis, what is there defective metabolism of?
Zinc and copper
The Millon reaction stains tyrosine which colour?
Orange
Which cat breeds are reported with urticaria pigmentosa?
Sphynx
Himalayan
Devon Rex
Siamese
Urticaria pigmentosa is a hyperplasia of which inflammatory cell?
Mast cells
A mutation in which gene is associated with ichthyosis in Golden Retrievers?
PNPLA1 - (insertion-deletion) AND ABHD5 (deletion)
A mutation in which gene is associated with ichthyosis in American bulldogs?
NIPAL4 (ICHTHYN) - deletion
A mutation in which gene is associated with ichthyosis in Jack Russell Terriers?
Transglutaminase 1 (TGM1) - insertion
A congenital and familial form of keratoconjunctivitis sicca and a roughened/curly hair coat with scaling, abdominal hyperpigmentation, foot pad hyperkeratosis and nail dystrophy has been recognised in which breed of dog?
Where is the gene mutation?
CKCS
FAM83H (deletion)
Which gene is mutated in nasal parakeratosis of Labrador retrievers and Greyhounds?
SUV39H2 (deletion)