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Flashcards in Equine Derm Deck (54):
0

Potential infectious skin diseases of horses?

- ectparasites
- dermatophilosis
- folliculitis
- fungal (dermatopyhtosis)
- viral (aural plaques)

1

Non-infectious equine skin diseases?

- allergies
- immune mediated
- endocrinopathy
- misc
- neoplasia

2

Which ectoparasites affect horses? Esp common?

- chorioptes mite esp common (limbs and tail)
- psoroptes mite bit common (head and ears)
- neotrombicula autumnalis, Dermanyssus gallinae (seasonal)
- rarely: scabies, demodecosis
- ticks, lice, fleas, flies

3

Where is chorioptes often seen?

- feathered hgorses
- pastern dermatitis
- peaks in winter

4

Clinical signs chorioptes?

- pruritis, erythema, crusts, papules

5

Tx chorioptic mange?

- fipronbil spray (repeat monthly, lots needed)
- avermectins (efficacy controversial)
- permethrins/pyrethroids (flumethrin acaricidaL)
> clip feathers

6

Clinical signs of lice infestation?

- pruritis variable
- identify parasites!! people overlook

7

Tx lice infestation

- fipronil spray
- syth pyrethroids
- systemic ivermectin (H. Asini sucking lice)

8

are lice contagious?

Yes but species specific so only horses need treating

9

How may flies cause problems in horses?

- bites and stings
- infected woudns
- hypersensitivity (esp culicoides sweet itch)
- laral myasis
- disease transmission (habronemiasis and onchocerchiasis)

10

What worms cause itchy bottoms?

- pinworms
- oxyuris equi
> adults migrate from LI out of anus to lay eggs
- self trauma

11

Most common skin allergy in horses?

Sweet itch
- insect bite hypersensitivity

12

Where is sweet itch seen? WHen?

USually dorsal but ventral fly also exists
- always seasonal! Not winter

13

Clinical signs of sweet itch??

- papules, crusts, skin thickening, alopecia
- seasonal pruritis

14

What aged hroses sweet itch affect?

- > 6 months

15

Ddx sweet itch?

- oxyuris equi
- insects
- other allergies

16

Is intradermal testing for sweet itch indicated?

- shows exposure not hypersensitivity

17

Does ASIT work for sweet itch?

No!!

18

Tx sweet itch?

- anti-inflammatories/antipruritic (antihistamines, GCs)
- management
> flies live in areas of wet fields and low winds and cannot fly far
> move horses!
> rungs/hoods/fly spray
> stable between 4pm and 8am
> long term insecticides and repellants (synth pyrethroids [cypermethrin, flumethrin, deltamethrin, CARE FLISH!]

19

Most common bacterial disease on the horse? How are these diagnosed? `

- Dermatophylsis congolensis (actinomyces) mud fever, affects cattle too if rain heavy > cytology on whole crust mixed with saline: "railroad tracks" may branch (not bacterial culture!)
- Staph aureus/pseudintermedius (NB. superficial pyoderma can be painful) > cytology
- rarely strep infections

20

Which horses are predisposed to med fever?

White limbs

21

When do cattle get rain salad/mud fever?

Serious tick infestation (Africa severe form)
- allows opportunistic Dermatophylsis congolensis

22

What does Dermatophylsis congolensis cause I'm other species ?

Rain scald
Sheep wool something
Cattle

23

What is mud ever also known as?

Mud rash
Greasy heel
Pastern folliculitis

24

Management and treatment of mud fever?

*Look up papers*
Management and husbandry changes
- chorioptes/ringworm/other pahtogens in mixed infection eradicated

25

What are aural plaques?

- papillomavirus infection
- hyperkeratotic plaques
- concave aspect pinnae
- common esp. yearlings and older
- Simulan spp. (midges) = vectors
- often persist but do not bother horse!!
- therapy = observation, do not tx unless causing problems!

26

Why is dermatophytosis treatement always indicated?

Zoonotic and contagious

27

Which species cause ringworm in horses?

- trichopyton
- m equinum and m gypseum

28

Pathogenesis of ringworm?

Resolvves in healthy horse within 5-6 weeks

29

CLinical signs dermatophytosis?

- may be pruritic
- same principles as SA (hair pluck/brush submit for fungal culture)

30

Tx ringworm?

> NOTHING LIC IN HORSES
> offlicense:
- topical griseofulvin/potassium iodide
- malaseb
- isolation and hygeine

31

Vax for dermatophytosis in the hrose?

No

32

What is a comon signs of horse with allergy?

- urticaria +- pruritis
> culicoides/food/atopic/{contact dermatitis?}

33

Potential immune mediated/autoimmune skin disease in horse?

- pemphigous foliacious (often accompanied by swelling and oedema)
- erythema multiforme [reaction pattern, not Dx] (may look = urticaria but urticaria will pit on pressure, erythema will not pit)
- adverse drug reactions
- vasculitis [reaction pattern, not Dx] (purpura haemorrhagica)
- alopecia areata (immune attack hair roots)
> reaction patterns may indicate neoplasia, infection etc.

34

What is PPID?

- cushings
- pituitary pars intermedia dysfunction
- hyperplasia of pituitary pars intermedia

35

clinical signs of PPID?

- old horses/ponies
- PUPD
- lethargy
- poor thriving
- 2* infections ^?
- hirsuitism
- laminitis
> MORE SEE SLIDE

36

What are systemic granulomatous diseases?

- or chronic eosinophilic enteritis (may be same thing or slightly different diseases?)
- also known as equine sarcoidosis (NOT RELATED TO SARCOIDS)
- wasting disease
- skin and GI affected
- aetiology unknown (hairy vetch? mycobacterium? viral antigen?)
- grave prognosis

37

Tx systemic granulomatous diseaase? Prognosis?

- change feed
- systemic GC months
- spontaneous recovery?
> prog grave

38

Clinical sings and dx of systemic granulomatos disease?

- exfoliative dermatitis (scaling)
- crusting
SEE SLIDE ADD MORE

39

How sudden onst is systemic granulomatous disease?

Acute onset v sudden onset

40

How id dx systemic granuloatous?

- liver function tests
- histopath

41

WHat 3 factors needed for photosensitisation? What 2 forms exist?

1* ( st. johns wort, phenothiazine)
2* (phylloerythrin due to liver disease)
> UV + poorly pigmented skin+ photodynamic agent in skin all needed

42

What photo induced disease are white limbs susceptable to?

- leucocytoclastic vasculitis
> acute onset erythema, oozing, crusting
> v painful

43

Dx. leucocytoclastic vasculitis?

- biopsy
( sedate first!!)

44

3 possible groups of nodular skin issues?

1. sterile (often harmless, little known about them)
- collagenolytic granuloma
- cutaneous mastocytosis
- axillary nodular necrosis
- unilateral papillomatosis
2. infectious(microbial/parasitic - can be tx)
- botryomycosis
- habronemiasis
- dermatophilosis
- dermatophytosis
3. neoplastic
- malignant
- benign

45

What is eosinophilic granuloma also known as?

- eosinophilic grnauloma
- nodular necrobiosis
- SEE SLIDE

46

CLinical signs eosinophilic granuloma?

see slide

47

Dx collagenolytic granuloma?

- history (not v speciffic)
> afge, speed of onset, seasonality, tx, systemic disease
- tests
> fungal/bacterial culture
> FNA cytology
> histopath for definitive dx

48

Ddx collagenolytic granuloma?

See slide

49

Is collagenolytic grnauloma harmful to horse?

No

50

Tx collagenolytic granuloma

- leave alone
- surgical excission if few
- GCs (systemic, intralesional, sublesional)

51

Prognosis collagenolytic granuloma?

see slife

52

See slide for sarcoid types Ddx

***

53

Which other species may get sarcoids?

- felines (esp. farm cats, zoo cats too)