Equine infectious dermatological disease

Question 1

Give examples of equine bacterial dermatological disease

Answer 1

Streptococcal dermatitis
Staphylococcal dermatitis
Dermatophilosis (rain scald)

Question 2

Give an example of equine fungal dermatological disease

Answer 2

Dermatophytosis (ring worm)

Question 3

Give examples of equine viral dermatological diseases

Answer 3

Viral papilloma (grass warts)
Pinnal acanthosis
Coital exanthema
Horse pox
Papular dermatitis
Sarcoids?

Question 4

What does streptococcal dermatitis cause? How is it diagnosed and treated?

Answer 4

Mild-moderate painful skin infections and abscess
Dx by culture
Tx - penicillin, drain abscesses, topical antimicrobials

Question 5

What are the most common causes of staphylococcal dermatitis?

Answer 5

Staphylococcus aureus

Staphylococcus intermedius

Question 6

What are the symptoms of staphylococcal dermatitis?

Answer 6

Pain
Localised exudative dermatitis
Focal lesions (abscess or pyogranulomas)
Pastern folliculitis, wound infections

Question 7

Treatment for staphylococcal dermatitis is quite problematic. How can it be treated?

Answer 7

Drain abscesses
Clip hair and antiseptic wash
Antimicrobials based on culture and sensitivity

Question 8

What is dermatophilosis commonly known as? What causes this?

Answer 8

Rain scald

Dermatophilus congolensis

Question 9

What does dermatophilosis cause? When is it more severe?

Answer 9

Mild pain and small lesions- easily to feel than see

Winter - longer matted hair

Question 10

How is dermatophilosis diagnosed and treated?

Answer 10

Dx - clinical signs, smears and culture

Tx - move to dry environment, remove matted hair and crusts, antimicrobial washes

Question 11

Dermatophytosis/Ringworm is very common, highly contagious and zoonotic. What is the incubation period?

Answer 11

2-3 weeks

Question 12

Do animals develop immunity against dermatophytosis?

Answer 12

Some with age

If reinfected - smaller lesions and faster recovery

Question 13

What are the 2 main types of fungi that cause ring worm?

Answer 13

Trichophyton

Microsporum

Question 14

What are the species of trichophyton and microsporum that can cause dermatophytosis?

Answer 14

T equinum var equinum
T verrucosum
M gypseum
M equinum

Question 15

What are the signs of ring worm?

Answer 15

Small circular patches with hair sticking up
Accumulation of keratinised squames - like cigarette ash
Bald patches from weakening of hairs

Question 16

How is ringworm diagnosed?

Answer 16

Skin scraping/hair pluck and microscopy
PCR
Culture - takes long time!

Question 17

How is ringworm treated?

Answer 17

Isolation
Usually resolves itself in 10 wks
Topical treatment (miconazole)
Disinfect environment and tack

Question 18

What is viral papilloma? What does it cause? Is it contagious?

Answer 18

Host specific papovavirus
Causes small pink/grey lesions on muzzle, lips, limbs and genitals. No sign of discomfort/pruritis
Moderately

Question 19

How are viral papillomas treated?

Answer 19

Can be removed, autogenous vaccinations and topical antivirals
However spontaneoulsy resolv

Question 20

How are viral papillomas diagnosed?

Answer 20

Biopsy or virus isolation

Question 21

Pinnal acanthosis or aural plaques are very common in horses. What virus causes them? What transmits this virus?

Answer 21

Papillomavirus 
Black flies (simulium spp)

Question 22

What is the Dx and Tx for pinnal acanthosis or aural plaques?

Answer 22

Don’t biopsy! Dx by clinical signs

Don’t treat

Question 23

What is coital exanthema? Is it contagious?

Answer 23

Disease caused by EHV-3

Yes

Question 24

How is coital exanthema transmitted?

Answer 24

Sexually, by indirect contact or inhalation

Question 25

Coital exanthema is only significant in breeding animals. Do horses become immune to this?

Answer 25

Yes - usually only infected once

Question 26

What is the incubation time for coital exanthema?

Answer 26

1 week

Question 27

Clinical signs are used to diagnose coital exanthema. What are these signs?

Answer 27

Papules on penis, vulva and perineum | Mildly pruritic, unpainful lesions may leave depigmented spots

Question 28

How is coital exanthema treated?

Answer 28

Don't breed until 3 wks after clear | Topical antimicrobials/antiseptics

Question 29

Horse pox is very rare. It comes in two forms. What are these?

Answer 29

Buccal form | Cutaneous form

Question 30

What are the clinical signs and treatment for horse pox?

Answer 30

Mild systemic signs - fever, depression | No treatment - spontaneous regression

Question 31

Papular dermatosis is very rare and only found in Africa and America. What causes this? Are they pruritic or painful? Do they need to be treated?

Answer 31

Unspecified pox virus No - non pruritic and non painful No treatment needed

Question 32

What are sarcoids? What is thought to be associated with sarcoids?

Answer 32

Common skin tumour in fibroblasts of horses | Bovine papillomavirus 1&2

Question 33

What predisposition can lead to sarcoids?

Answer 33

Genetic predisposition

Question 34

What are the 6 forms of sarcoids?

Answer 34

``` Occult Verrucose Nodular Fibroblastic Malignant Mixed ```

Question 35

What is a danger of biopsy of sarcoids?

Answer 35

Can exacerbate conditions

Question 36

There are lots of treatments for sarcoids. What are examples of treatments?

Answer 36

``` Surgery Laser therapy Immune therapy Cytotoxins Antimitotics Radiation Homeopathy ```

Question 37

What are the general rules for sarcoids?

Answer 37

The more they have the more they get and vice versa Multiply over Summer and grow over Winter Single sarcoid implies genetic susceptibility