Equine Derm Flashcards
0
Q
Non-infectious equine skin diseases?
A
- allergies
- immune mediated
- endocrinopathy
- misc
- neoplasia
1
Q
Potential infectious skin diseases of horses?
A
- ectparasites
- dermatophilosis
- folliculitis
- fungal (dermatopyhtosis)
- viral (aural plaques)
2
Q
Which ectoparasites affect horses? Esp common?
A
- 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
Q
Where is chorioptes often seen?
A
- feathered hgorses
- pastern dermatitis
- peaks in winter
4
Q
Clinical signs chorioptes?
A
- pruritis, erythema, crusts, papules
5
Q
Tx chorioptic mange?
A
- fipronbil spray (repeat monthly, lots needed)
- avermectins (efficacy controversial)
- permethrins/pyrethroids (flumethrin acaricidaL)
> clip feathers
6
Q
Clinical signs of lice infestation?
A
- pruritis variable
- identify parasites!! people overlook
7
Q
Tx lice infestation
A
- fipronil spray
- syth pyrethroids
- systemic ivermectin (H. Asini sucking lice)
8
Q
are lice contagious?
A
Yes but species specific so only horses need treating
9
Q
How may flies cause problems in horses?
A
- bites and stings
- infected woudns
- hypersensitivity (esp culicoides sweet itch)
- laral myasis
- disease transmission (habronemiasis and onchocerchiasis)
10
Q
What worms cause itchy bottoms?
A
- pinworms
- oxyuris equi
> adults migrate from LI out of anus to lay eggs - self trauma
11
Q
Most common skin allergy in horses?
A
Sweet itch
- insect bite hypersensitivity
12
Q
Where is sweet itch seen? WHen?
A
USually dorsal but ventral fly also exists
- always seasonal! Not winter
13
Q
Clinical signs of sweet itch??
A
- papules, crusts, skin thickening, alopecia
- seasonal pruritis
14
Q
What aged hroses sweet itch affect?
A
- > 6 months
15
Q
Ddx sweet itch?
A
- oxyuris equi
- insects
- other allergies
16
Q
Is intradermal testing for sweet itch indicated?
A
- shows exposure not hypersensitivity
17
Q
Does ASIT work for sweet itch?
A
No!!
18
Q
Tx sweet itch?
A
- 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
Q
Most common bacterial disease on the horse? How are these diagnosed? `
A
- 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
Q
Which horses are predisposed to med fever?
A
White limbs
21
Q
When do cattle get rain salad/mud fever?
A
Serious tick infestation (Africa severe form)
- allows opportunistic Dermatophylsis congolensis
22
Q
What does Dermatophylsis congolensis cause I’m other species ?
A
Rain scald
Sheep wool something
Cattle
23
Q
What is mud ever also known as?
A
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)
