Skin Disease Flashcards
What are three main layers of horse skin and what does each contain?
Epidermis: Outer protective layer
Dermis: Contains blood vessels, nerves, and connective tissue.
Adnexa: Includes hair follicles and glands.
What factors help diagnose equine skin diseases?
History, age, breed, season, environment, lesion distribution, cultures, smears, scrapings, histopathology, and response to treatment.
What are the three most common skin tumors in horses?
Sarcoids (most common), melanomas (in grays), and squamous cell carcinomas
What causes Dermatophilosis (Rain Scald)?
Dermatophilus congolensis, an opportunistic bacterium activated by prolonged wetting of the skin.
What are the clinical signs of dermatophilosis?
Paintbrush lesions, crusts, exudative dermatitis, pus under scab.
How is Dermatophilosis treated?
Keep the horse dry, apply antiseptic washes (Betadine and chlorhexidine), and use waterproof creams.
Ringworm-Cause
Fungi, primarily Trichophyton and Microsporum species.
What are the clinical signs of Ringworm?
Circular patches of raised hair, bald areas with scaling. and keratinized squames.
How is Ringworm treated?
Remove scabs, apply anti fungal washes (povidone-iodine), treat the environment, and isolate infected horses.
Insect Hypersensitivity-Cause
Immune response to the saliva of Culicoides (biting midges).
Insect Hypersensitivity-Clinical Signs
Severe itching, hair loss, lesions on the neck, belly and dorsum.
How is insect hypersensitivity controlled and treated?
Use fly sheets, stabling during peak midge activity, topical insecticides, and antihistamines or corticosteroids.
What causes pastern heel dermatitis (scratches)?
Prolonged wetting of the distal limbs, poor hygiene, and secondary bacterial or fungal infections.
How is pastern heel dermatitis treated?
Remove scabs, keep the area dry, and apply topical antibiotics or antifungals.
What are the two main type of lice affecting horses?
Biting lice (Damalinia equi) and sucking lice (Haematopinus asini).
How are lice controlled and treated in horses?
Use permethrin or cypermethrin treatments, repeat every 10 days, and clean all tack and bedding.
What is Chorioptic Mange, and what are its signs?
Caused by Chorioptes mites; signs include foot stamping, serum exudate, and pruritus.
How is mange treated?
Clipping, shampoos, topical treatments like firpronil, and treating all in-contact horses.
What are key feature of melanomas in horses?
Black masses, usually in gray horses over 8 years, found in the perineum, eyelids, or lymph nodes.
How are sarcoids managed in horses?
Surgical excision, cryotherapy, immunomodulation (BCG injections), and topical cytotoxic agents.
Hard to treat come back and spread
dont metacize
What factors predispose horses to squamous cell carcinoma?
UV exposure, penile smegma, and mucocutaneous junction sites.
How are squamous cell carcinomas treated?
Surgical excision, cryotherapy, radiation therapy, and cisplatin.
