Miscellaneous Flashcards
What is the epidermal cell renewal time in normal dogs?
Approximately 22 days
What is the most common acquired keratinization defect?
The callus
What percent water content was the skin be for it to appear and feel normal?
At least 10%
What are three important intercellular lipid components?
Sphingolipis, free sterols, free fatty acids
What is the optimal stratum corneum water concentration to promote softness and pliability?
20-35%
Seborrhea sicca
dryness of the skin and cat; focal or diffuse scaling of the skin with the accumulation of white to gray non adherent scales, the coat is dull and dry
Seborrhea oleosa
The skin and hairs are greasy and greasy keratosebaceous debris is best appreciated by touch and smell.
Seborrheic dermatitis
scaling and greasiness with gross evidence of local or diffuse inflammation
What are some causes of secondary canine seborrhea?
- Any disorder that alters cellular proliferation, differentiation or desquamation produced seborrheic signs
1) Inflammation can increase the DNA synthesis is the basal layer and stimulate epidermal proliferation; ex: too-vigorous grooming, demodicosis, dermatophytosis, cheyletiellosis, lice, low-grade contact dermatitis and early epitheliotropic lymphoma
2) Endocrine factors: hormones influence cellular proliferation and serum/cutaneous lipid profiles. Commonly seen with spontaneous/iatrogenic hypercortisolemia and hypothyroidism
3) Nutritional factors: uncommon cause as most dogs are fed a high quality, balanced diet; can be due to deficiency or excess or imbalance in glucose, protein, essential fatty acids and various vitamins/trace minerals. Intentional fatty acid deficiency for weight loss or control of pancreatitis or abnormalities in lipid metabolism.
4) Environmental factors: low environmental humidity, excessive bathing (especially with harsh products) and fatty acid deficiency can result in increased trans epidermal water loss . Low winter humidity
What breed is primarily reported with Vitamin A responsive dermatosis?
Cocker spaniels; also seen in Labrador retrievers and miniature schnauzers and other breeds
What are the clinical features of vitamin A responsive dermatosis?
- Adult-onset medically refractory seborrheic skin disease
- Marked follicular plugging
- Hyperkeratotic plaques with surface fronds
- Follicular plugging/hyperkeratotic plaques especially prominent on the ventral and lateral chest and abdomen
- Focal crusting, scaling, alopecia and follicular papule
- Ceruminous otitis
- Dry, dull, disheveled easily epilated hair coat is usually present
- Dogs are generally healthy otherwise
- A group of Gordon-setters were pruritic with a vitamin-A responsive dermatosis condition
- Histologically: profound and disproportionately marked follicular orthokeratotic hyperkeratosis
What are 7 conditions that can cause marked follicular plugging?
- Vitamin-A responsive dermatosis
- Hypercortisolemia
- Sebaceous adenittis
- True vitamin A deficiency
- Hypervitaminosis A
- Atypical generalized demodicosis
- Follicular dysplasia
What are primary differentials for generalized non-pruritic feline seborrhea sicca?
- Dietary deficiency (common for cats feeding fat a low fat diet or diet for hepatic lipidosis to develop a dull, dry and flaky coat
- Intestinal parasitism
- Low environmental humidity
- Diabetes mellitus
- Hyperthyroidism
- Cheyletiellosis
- Pediculosis
- Contact dermatitis or overzealous shampooing/powdering
What are primary differentials for localized and/or pruritic feline seborrhea sicca?
- Demodicosis
- Dermatophytosis
- lymphocytic mural folliculitis
What are differentials for feline seborrhea oleosa?
typically indicate severe hepatic, pancreatic or intestinal disease. drug eruption, SLE