Lecture: Demodicosis Flashcards Preview

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Flashcards in Lecture: Demodicosis Deck (32)
1

pathogenesis Demodex

  • Deficient cell mediated immune response
  • Genetics, autosomal recessive
  • Immunosuppression
  • Bacterial folliculitis

2

Any dog (animal I think) positive for demodex needs to be

on an antibiotic

(something about staph receptor on demodex...blah blah blah)

3

Demodex and contagiousness

Not contagious

4

Demodex

CS

  • Papules/pustules, erythema
  • Alopecia
  • Scaling, crusting

5

common places for demodex

face and feet

6

Comedones

  • follicular plugging (blackheads)
  • comedeones on feet, MUST SCRAPE

7

DDX for comedones

  • endocrine dz
  • demodex

8

Grey patchy skin from far away

  • thick folliculitis
  • think comedones
  • scrape for demodex

9

Demodex lives inside

hair follicle

10

Demodex DX

  • Pinch, scrape in direction of hair, till blood
  • pluck the hair (not as sensitive as a scrape)
  • Biopsy where comedones are
    • shar pei
    • scar tissue (hot spots)
    • pododermatitis

11

juvenile demodex

genetically inherited dz....?!?!

12

Adult demodex indicates

an underlying disease

13

If demodex on deep scraping is diagnosed

  1. Is it generalized?
    • scrape 5 places total
  2. If it's not generalized, will it become generalized?
    • don't treat, wait and see (if a breeding animal)

14

Localized Demodicosis - Prognosis

  • 90 % of localized juvenile demodecosis will spontanously clear up

15

Generalized demodicosis in breeding animals...

These animals should not have puppies

16

TX localized juvenile demodicosis

  • Antibiotics
    • topical benzoyl peroxide gel/shampoo
    • systemic if needed
  • De-worming, good diet, HW, TLC

*do not use steroids, or anti-mite therapy

17

Localized demodicosis

  • monitor course of disease
    • recheck in 2-4 weeks
    • deep scrape skin same 5 spots
      • if mite counts decrease: lesion resolving, recheck q 4 weeks until negative
      • if mite counts inc: may be progressing to generalized

18

Generalized Demodicosis

  • 5 localized lesions or more
  • involvement of an entire body region (ie: head)
  • Involves 2 or more feet

19

rate of clearance of gen juvenile onset demodicosis

50% of self clearance rate with an antibiotic

50% need anti-mite prescription

5% need lifelong treatment

20

Adult onset generalized demodex

may precurse cushings, or other endocrine/metabolic dz

underlying immunosuppression.... (steroid misuse)

21

Pododemodicosis

  • very painful

22

Generalized Demodicosis

TX

  1. Miticide
  2. Antibiotics
    • treat secondary bacterial infections
    • until neg 1st scrape
  3. Benzoyl Peroxide shampoo (2.5%)
    • Follicular flushing

23

Generalized Demodicosis

RX to kill mites

  1. Amitraz = Mitaban
  2. Ivermectin = Ivomec
  3. Milbemycin = Interceptor (not available right now)

24

Amitraz

  • Topical
  • only FDA approved tx
  • MOI, alpha-2 adrenergic agonist, inhibits prostaglandin synthesis
  • there are side-effects and it is labor intensive
  • 6-9 weeks no response is a failure

25

Amitraz (mitoban) pitfalls

  • toy breeds and toxicity
  • Sick, old patients
  • extensive ulcerations

26

Amitraz

side effects

  • Sedation/dull mentation
  • reversals
    • yohimbine
    • antipamezole
  • avoid use in owners with
    • asthma
    • diabetes (or animals with diabetes)
    • owner taking MOA: Parkinson's disease

27

Amitraz failure

  • No improvement after 6-9 months
  • untreated staph infection

28

Ivermectin (Ivomectin)

  • off label
  • Dose:
    • 400-600 microgram (0.4-0.6 milligrams)
    • HW prevention dose is 6 micrograms
    • 1% ivermectin is 10mg/mL
    • toxic dose for collies/shelties is 100 micrograms ( 0.1 mg)
  • build up to final dose
  • monitor patient, educate patients
    • look for pupils and glazed look

29

Ivermectin: white feet

dont treat

30

Moxidectin

  • Advantage multi
  • weekly or every other week

31

Bravecto (flurolaner)

  • 1 pill (lasts 12 weeks) eliminates 100% mites by day 56
  • Safe for the white feets

32

Generalized Demodicosis

TX monitoring plan

  • deep skin scrape
    • 5 sites
    • always include muzzle and feet
  • record mites
  • re-scrape same sites q 4 weeks
  • treat until 3 consecutive negative skin scrapes