Lecture 5 Flashcards
Demodex life cycle
Normal inhabitant Obligate parasite 25-30 days Feeds on cellular debris Goes from egg to 6 legs to 8 legged nymph to 8 legged adult
How is it transmitted
Bitch to puppies in 1-3 days of life
How does demodex cause dises
Abnormal proliferation
Pathogenesis of demodex
Deficient cell mediated immune response
Genetics
Immunosuppression
Bacterial folliculitis
Contagious or zoonotic?
No and no
Clin signs of demodex
Papules/pustules, erythema, alopecia, scaling/crusting, comedones
Demodex diagnosis
Deep skin scrapes
Hair plucks
Biopsy (shar peis, scar tissues, pododermatitis)
What forms of demodex are there
Juvenile- local or general
Adult- local or general
Small breeds- 12 mo
Large breeds- 18 mo
Giant breeds- 24 mo
What is localized juvenile demodex
Mites in 1/5 areas from deep skin scrapes
Prognoses for localized juvenile demodex
Good!
90% will clear spontaneously
Treatment for juvenile localized demodex
Benign neglect
Abx if pustular
TLC
NO steroids or antimite therapy
What is generalized demodex
5 localized lesions or more
2 or more feet
What causes generalized juvenile demodex? What is prognosis?
Hereditary- spay/neuter
50-50 will self clear
What causes generalized adult demodex
Juvenile that never cleared Underlying immunosuppression (steroids, endocrine, metabolic, neoplasic)
May have pododemodicosis
Treatment for gneralized demodex
Miticide
Abx until first neg scrape
Benzoyl peroxide shampoo
What are you miticide options
Amitraz- only FDA approved treatment
Ivermectin
Milbemycin
Who should you be careful to use amitraz in
Toy breeds
Sick old patients
Extensive ulcerations
*also owners with asthma, diabetes, or taking MOA
What should you use in amitraz resistant cases? Who should you not use it in
Ivermectin
Collies/ border collies Shelties OESD Australian shephers “White feet dont treat”
What are options for dogs that can’t get ivermectin
Moxidectin
Bravecto
Nexgard
Simparica
What should you always include on your deep skin scrap
Muzzle
Two feet
When can you stop treatment
3 consecutive neg skin scrapes at 4 wk intervals
Species of feline demodex
D. Cati
D. Gatoi
Rare
Where does d. Cati go? What causes it? How to dx?
Follicles
Head and neck pruritus
Immunosuppression- diabetes, FeLV/FIV, metabolic dz
Deep skin scrape
Where does d. Gatoi go? What causes it? How to dx?
S.corneum
Contagious
Pruritic on trunk and head/neck
Superficial skin scraping
