General approach to the dermatological patient

Question 1

What are the most common DAMNITV causes of dermatological disease?

Answer 1

Metabolic
Neoplastic
Inflammatory
Immune-mediated
Infectious
Traumatic

Question 2

Give examples of how sex links to skin disease

Answer 2

Entire male – endocrine changes from testicular neoplasia (dog)
Entire female – post-whelping bitch can suffer temporary generalised alopecia

Question 3

Give examples of breed dispositions to skin disease

Answer 3

Welsh ponies – Culicoides hypersensitivity
Feathered horses/ponies – Chorioptic mange
Persian cats, Yorkshire terriers – dermatophytosis
Staffordshire Bull Terriers, Shar Pei, Bulldogs – demodicosis
Shar Pei, French/English bulldogs, Labradors (+ others!) – environmental atopy

Question 4

Give examples of how housing can impact skin disease

Answer 4

Lice, dermatophytosis more common in housed farm animals/horses
Chorioptes more common in stabled horses
Culicoides hypersensitivity more common if out at grass at dawn/dusk
Overcrowding/stocking density e.g. at the feed trough - facial dermatitis in sheep
Dermatophilosis (rain scald/mud fever) more common in wet conditions

Question 5

Give examples of how lifestyle can impact skin disease

Answer 5

Hunting terriers – more prone to Trichophyton dermatophyte infections (from rodents)
Hunting cats – risk of cowpox

Question 6

Give an example of how underlying systemic disease can impact skin disease diagnosis

Answer 6

e.g. In hyperadrenocorticism ( a cause of alopecia) the owners will usually report marked polydipsia and polyphagia

Question 7

What in house tests can be done when diagnosing skin diseases?

Answer 7

Coat brushing
Skin scrapes
Skin cytology
Dermatophyte culture
Trichograms
Wood’s lamp examination

Question 8

What lab tests can be done to diagnose skin diseases?

Answer 8

Bloods e.g. Haematology & biochemistry
or endocrine testing
Bacteria: culture and susceptibility
Fungal culture / PCR
Virus isolation
Biopsy

Question 9

A 3yo FN Labrador presents to you with lesions on the ventrum
The dog has developed these lesions over the past week, but they have not been seen before. She has, however, suffered from low-grade pruritus of the ventrum, face and feet for the past 12 months, and ventral pruritus has increased in the past 1-2 weeks
The in-contact dogs and people are fine, and her general health is good
All dogs are treated every 4 weeks with sarolaner/milbemycin tablets
There is no contact with other animals or change of environment

What is your differential diagnosis list?

Answer 9

Question 10

You are asked to look at a 2yo Scottish Blackface ewe in December, as the farmer is concerned about a skin problem he has just noticed
The ewe is one of a group of 30 that are currently housed
Similar lesions have been found today on a few others in the group
They are believed to be pruritic, though the farmer is still a little unsure on this point
The farmer has recently developed a red patch of skin on her hand
The sheep are well otherwise

What is your ranked differential diagnosis list and how would you test these?

Answer 10