Canine Dermatology Case study module 3

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Case study module 3
6 month old West Highland white terrier

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History and clinical
presentation
Pruritus
Erythema
Lichenification
Hyperpigmentation
Crusting

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Case work up
 List the further history needed
 List the differential diagnosis
 List the tests in order of how best to progress with the
investigations

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Questions
regarding
further history
 How long has the condition been going on
 What treatments and responses
 Diet
 Management – walking and indoor environment
 Other pets in the house?
 Is there a smell associated with the condition
 Zoonosis

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History for this case
 Fed on commercial puppy food, milk and other treats
 Walked on grass and pavement
 Indoor environment carpeted and sleeps on the owners bed
 Owners unaffected
 Owner reports a cheesy smell since the dog developed the disease
 Duration for about 6 weeks (so started at the age of about 18 weeks)
 Treated with antibiotic – cefalexin but this had no effect
 Washing with a tea tree oil shampoo bought in the pet shop

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List of differential diagnosis
 Malassezia dermatitis
 Demodicosis
 Adverse food reaction
 Atopic dermatitis
 Sarcoptic mange

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Tests in order of importance
 Skin scrapes
 Tape strip cytology
 Consider trial treatment for sarcoptic mange if high
index of suspicion
 Food trial
 Serum or intradermal allergy testing if the criteria for
atopic dermatitis are fulfilled

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Further investigations in this
case
 Skin scrapes
 Negative for demodex mites
 Tape strips
 See picture
 Trial treat for sarcoptic mange

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Questions
 How would you treat this dog?
 What steps would you take to investigate this case
further?

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Questions
 How would you treat this dog?
 Antifungal shampoo and in this case systemic antifungal – itraconazole
10mg/kg sid with food for 14 days
 Treatment until negative cytology
 What steps would you take to investigate this case further
 Maintain flea control
 Diet trial
 Finally clinical diagnosis of atopic dermatitis if pruritus persists

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Ongoing investigations and outcome
 Shampoo in 2% chlorhexidine and 2% miconazole (Malaseb; shampoo)
once a week
 Food trial with Purina Veterinary Diet a hydrolysed commercial diet for 8
weeks
 Pruritus resolved
 Relapsed when fed the original food including the milk and treats.
 The prognosis is good although the Malassezia dermatitis could recur
 Concurrent allergies to environmental allergens possible in due course

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Outcome: response to food trial and antifungal
treatment