Equine Dermatology Cases Flashcards
Case 1
- 10yo Oldenburg (fancy German Breed) gelding
- Acute onset of lesions.
- Started at head and neck.
- Spread over 5 days.
- Recent addition of electrolyte to feed.
- Recent change in bedding = now on pellet shavings ‘ProBed’.
- No previous history of skin disease.
* lumps + bumps under skin across body
- What is the condition?
- Urticaria
What is urticaria?
- Mast Cell Degranulation = Immunological / Non-immunological
- Type I and Type III Hypersensitivity
- Pressure, temperature, exercise, stress, etc.
- It can sometimes be recurrent – Atopic Manifestation
How would you diagnose urticaria from other conditions?
Treatment trials
- probably hives = treat it and see what happens
What would be primary choice treatment for urticaria?
- Corticosteroids - one dose of dexamethasone usually
What else can be done for this horse with urticaria?
- Consider any changes to management and try to correct them
- Flies and dust mites are often indicated – rugs and decontamination
- Owners often blame feed or bedding changes
– Try to change back, but unlikely to be cause
Case 2
* 13y, Cob X, black, Gelding
* History of pruritus over body and face
* Treated with Dectomax, Panomec washes, Cavalesse
* Responded to steroids
- Dermatological exam =
– Scaling of face, neck and mane
– Areas of hair thinning consistent with pruritus
How would you investigate?
Ddx?
- Coat brushings - lice / mites (ectoparasites)
- Blood test - checking inner systems, allergy testing
Results show horse might be allergic - how do we figure what he’s allergic to?
- Intra-dermal allergy testing - Gold standard
After doing intra-dermal allergy testing what treatment should be done?
- Allergen specific immunotherapy
- Antihistamines
- Use of shampoos to remove allergens - oatmeal or aloe vera based
- Topical steroids - hydrocortisone
What management changes could be done?
- Stabling from dusk until dawn, when midges predominantly feed
- Use of rotating ceiling fan in stable (interferes with insect flight and navigation)
- Regular use of insect repellents – containing permethrins
- Use of insect-proof rugs, eg Boett blanket
- Removal of all loose bedding from stable and use of rubber matting only on floor
- Regular vacuuming and pressure cleaning of stable, ideally quarterly
- Regular laundering of rugs at high temperature
- Use of human anti-allergy mite-proof duvet cover in an outer polycotton duvet cover underneath rugs
Case 3
* 3 year old Shire gelding
* 3 Week hx of stamping back legs and chewing them when lying down
* Some scabs
* Owner tried louse powder and hibiscrub wash = No improvement
- What diagnostic tests could we do?
- Coat brushing - lice + mites highest on differential list
How should you treat chorioptes equi?
- Clip hair off the legs so Tx is easier
- Wash legs with either ivermectin wash or selenium sulphide shampoo
- Inject sub-cut doramectin
- Apply fipronil spray / pipettes to legs
Case 4
* 4 year old, grey, Cob gelding
* Episode of urticaria 6 weeks ago
* Since then skin “lumpy” and “scabby”
* Horse bit quieter than normal but fine generally
- HR40 RR12 T38.9
- Hard, crusty appearance to regions of skin. Almost cardboard like.
- Affecting limbs neck and trunk.
- Some ooze beneath the crusts.
- What is your approach?
- Pick a scab + smear discharge underneath for cytology
- Biopsy
Acantholyic keratinocytes seen = what does this indicate?
Pemphigus foliaceus
How do we treat pemphigus foliaceus in horses?
- Corticosteroids
How would you treat a sarcoid?
- Surgery / Cryo / Laser
- Immune therapy - BCG injections, vaccines
- Cytotoxics (topical + injection)
- Antimitotics (topical)
- Photodynamic therapy
- Radiation
- Homeopathy / natural medicine
