Scabies incognito in dog

stef artStroe Marina- Ștefania

6-th year student at FMVB, Faculty of Veterinary Medicine of Bucharest

Rottweiler dog, 1 year old, male, intact develop intense pruritus, mild erythema, crusts and less-hairy skin on the phalanges, hocks; no other cutaneous lesion than this diffuse erythema.

  • Other differentials (demodicosis, dermatophytosis, contact dermatitis, Malassezia dermatitis, hipersensitivity).
  • Pinnal-pedal reflex: rubbing of the ear margin and may obtain a scratch reflex.
  • The pinnal-pedal reflex in this case was positive
  • Microscopy

Superficial skin scraping: negative but false-negative results are commnon because mites are extremely difficult to find.

derm3

Macroconidia Alternaria alternata

derm2

Eggs/ova mites

Deep skin scraping: negative (for Demodex).

derm4

Malassezia spp.

Scotch test: detection of eggs/ova mites Sarcoptidae like, derm5 derm6Malassezia 8/OIF, bacterial cocci, macroconidia Alternaria alternata.

Serology (ELISA): detection of IgG antibodies against Sarcoptes. This is highly specific and sensitive test but false-negative results can occur. In this case the test was negative.

 

Diagnosis: “Scabies incognito”

 

Treatment and prognosis

  • Topical treatment applied to the entire body two times per week, 4-6 weeks. Bathing with a shampoo that contain chlorhexidine and antifungal (ketoconazole) – KetoHexidine shampoo 1%ketoconazole, 2%chlorhexidine.
  • Omega 3 and Omega 6 fatty acid supplements, which reduce inflammation and itching – Megaderm >10 kg, 1 dose/day, 1-2 months.
    • Systemic treatment with Ivermectin: 300-400 mcg/kg po or sc, once weekly for weeks. I use this scheme for 5 administration.
    • Recheck: progress, hair regrowth, decrease of the lesions.
    • The prognosis is good. S. scabiei is a highly contagious to other animals and to humans.