Derm1- Pruritic Parasites

  1. What are 2 tunneling mites?
    Sarcoptes scabiei (dog scabies), Notoedres cati (feline scabies)
  2. What is the surface mite?
    Cheyletiella- walking dandruff
  3. Describe the microscopic appearance of Sarcoptes scabiei.
    anterior unjointed stalks with suckers, posterior legs do not extend beyond border of body
  4. How long is the life cycle of Sarcoptes scabiei?
    12-21 days all on dog host
  5. Can humans get mites from their pets?
  6. How are Sarcoptes scabiei transmitted between hosts?
    direct contact with infested animal, fomites/fur
  7. What are clinical signs of canine scabies? (3)
    intense non-seasonal pruritus, minimally responsive to glucocorticoids (contrast to allergies), affects pinnal margins, lateral elbows, lateral hocks, ventrum
  8. What is the primary lesion with canine scabies? What are other secondary lesions? (6)
    • Primary: papules
    • Secondary: crusts, scale, alopecia, lichenification, hyperpigmentation, secondary pyoderma [scratching and self-trauma]
  9. _________ may develop after successful treatment and curing of canine scabies.
    Protective immunity----> asymptomatic carrier later on in life
  10. Why does canine scabies cause such severe pruritus? (pathogenesis)
    hypersensitivity due to feeding, oviposition, deposition of feces in stratum corneum +/- stratum spinosum--> antigens
  11. What is Norwegian scabies?
    less severe to no pruritus, mites in large numbers, thick adherent crusts [rarer form of canine scabies]
  12. How do you get a definitive diagnosis of canine scabies?
    find the mite or eggs microscopically [can be very difficult]- negative does not rule out
  13. How do you treat canine scabies? (5)
    [all patient and all animal in contact with them] Moxidectin and Imidacloprid, 2 treatments 28 days apart;Selamectin (Revolution) 2 txt 30 days apart; Ivermectin 1% 3-4txt every week; Frontline spray3 txt every 14 days; Lime Sulfur Dip in young or sick dogs (safe)
  14. What should you be sure to do before you begin treating a dog for scabies?
    evaluate heartworm status b/c txt agents are parasiticidal to heartworms
  15. Why can't you use the same scabies treatments for dogs and cats?
    Moxidectin in dogs is 2.5%, in cats its only'll kill the cat
  16. What breeds should never ever get Ivermectin? (5)
    Collies, Sheepdogs, Australian and German Shepherds, long-haired Whippets, or crosses of these breeds [ABCB1-1D (MDR1) gene]
  17. What species can you kill with fipronil spray (Frontline spray)?
  18. When will you see resolution of clinical signs of canine scabies after txt initiation?
    2 months
  19. How long is the life cycle in Notoedres cati?
    17-21 days
  20. How is Notoedres cati transmitted between hosts?
    direct contact with infested animal, fomites
  21. Clinical signs of Notoedres cati infection? (2)
    intense non-seasonal pruritus, affects ear pinnae, head, scruff, neck, perineum, feet, back (contrast to canine scabies b/c cats lick their backs and transfer mites)
  22. What primary lesions is associated with Notoredres cati? What are secondary lesions? (4)
    • Primary: erythematous papular eruptions on medial pinnae
    • Secondary: thick crusts, excoriations, alopecia, lichenification (self-trauma)
  23. How do you get a definitive diagnosis of Notoedres cati?
    find mite after superficial skin scrape- key areas are ears, face
  24. How do you treat Notoedric mange? (3)
    [treat ALL animals in contact with patient] topical dips after bathing with keratolytic shampoo to remove crusts- Lime Sulfur; Selamectin (Revolution) 1-2 txt 30 days apart; Imidacloprid and Moxidectin [all extra label]
  25. Describe the microscopic appearance of Cheyletiella spp.
    large, saddle shaped, hook-like accessary mouth parts, terminal combs
  26. How is Cheyletiella transmitted between hosts?
    direct contact, fomites (hair!!)
  27. How long is the life cycle of Cheyletiella?
    21-24 days on the host
  28. What type of mite can live up to 10 days off the host?
  29. Clinical signs associated with Cheyletiella. (3)
    variable pruritus, affects dorsal truncal area but can be generalized, dull greasy hair coat
  30. What is the primary lesion of Cheyletiella? What are secondary lesions? (4)
    • Primary: Papules
    • Secondary: crusts, scaling dermatitis, miliary dermatitis (cats)
  31. How do you diagnose Cheyletiella? (3)
    direct examination under microscope- acetate tape preparation, superficial skin scrape, flea comb- multiple sites; fecal float; therapeutic trial
  32. Which type of mite is only in small numbers, making definitive diagnosis difficult?
    Sarcoptes scabiei
  33. How do you treat Cheyletiella?
    [all animals in contact with patient] treat 2-4 weeks beyond resolution- clip hair and lime sulfur dip entire animal; Fipronil (Frontline); Selamectin (Revolution); Imicloprid and Moxidectin; Ivermectin; Mibemycin oxime (Interceptor)
  34. Which mite is it necessary to treat the environment for and why?
    Cheyletiella b/c they can live in the environment for 10 days
  35. ID
    Image Upload 1
    Sarcoptes scabiei
  36. ID
    Image Upload 2
    Cheyletiella spp.
Card Set
Derm1- Pruritic Parasites
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