Dermatology

Question 1

What is the common name for dermatophilosis and what organism is the causative agent?

Answer 1

‘Rain scald’ - caused by the gram positive actinomycete bacteria Dermatophilus congolensis

Question 2

‘Paintbrush lesions’ such as this indicate which infective agent?

Answer 2

Dermatophilus congolensis

‘Rain scald’

Question 3

What is the most common causative agent of ‘swamp cancer’?

Answer 3

Pythium insidiosum

(fungus-like eukaryotic microorganism)

Question 4

What is the best treatment for phycomycosis? (swamp cancer)

Answer 4

Combined surgical and medical treatment best:

• surgical excision of lesions with 2cm margins
• sodium iodide IV + topical antifungal agent (phycofixer)

*can try vaccination if lesions <2wks old*

Question 5

Which viral disease may have caused this?

Answer 5

Equine Herpes Virus - 3

‘Equine Coital Exanthema’

Question 6

How would you treat a case of equine coital exanthema?

Answer 6

The lesions will spontaneously heal over 3-5wks.

Symptomatic treatment: sexual rest and emollient agents to prevent seconary infection and preputial adhesions

Question 7

What is the intermediate host for onchocerca?

Answer 7

Culicoides (biting midgee)

Question 8

What would be at the top of your differential list if you saw a lesion like this (fistulous withers)?

Answer 8

Onchocerca

Adult worms locate in the nuchal ligament

Question 9

What is the name of the chewing lice of horses?

Answer 9

Bovicola equi

Question 10

What is the name of the sucking lice of horses?

Answer 10

Haematopinus asini

Question 11

What can affect how well a horse responds to treatment for pemphigus?

Answer 11

Age.

Spontaneous remission common in foals.

Horses <1y have less severe disease and respond better to treatment.

Horses >1y respond poorly and are often euthanised.