Canine demodicosis: Serious disease requires aggressive therapy

Canine demodicosis: Serious disease requires aggressive therapy

Nov 01, 2006

Doses of ivermectin for various diseases and side effects:

  • 5-6ug/kg—heartworm preventive
  • 50ug/kg—dirofilaricide
  • 200ug/kg—most common dosage for treatment of sarcoptic mange, LD50 of ivermectin-sensitive Collies and Australian Shepherds
  • 1,000ug/kg—mydriasis
  • 2,000ug/kg—weight loss, tremors, ataxia in 50 percent of dogs
  • 80,000ug/kg—LD 50 for general canine population

Photo 4: Demodex pododermatitis in a Lhasa Apso.

Photo 5: Adult Cocker Spaniel with demodex mites of the perioral area and demodex otitis.

Other therapies:
  • Taktic: Mix 1cc with 100cc water and use daily half-body applications. Resolution rate overall: 79 percent. Treatment duration: 3.7 months.
  • Preventic Collar: 9% amitraz. Not approved or studied for use in generalized demodicosis. Limited use has shown control of chronic demodicosis.
  • Vitamin E: Dr. Figueiredo (Brazil) studied 36 cases of juvenile- and adult-onset generalized demodicosis and found all had significantly lower serum Vitamin E levels than normal dogs. Twenty-seven dogs were treated with Vitamin E 200 IU orally five times daily. Within six weeks, 90 percent achieved negative skin scrapings. Griffin (1992) was unable to demonstrate significantly reduced levels of Vitamin E in generalized demodicosis with/without pyoderma. Vitamin E may be a beneficial concurrent therapy because of its immunomodulating properties.
  • Immunostimulants: Have not been evaluated for use in generalized demodicosis.
  • Lufenuron: Schwassman (1997) showed no improvement when used once daily for five days/month for two to three months at 13mg/kg or 15mg/kg administered times a week for two to three months in dogs with generalized demodicosis.
  • Selamectin: Anecdotal reports suggest it is not helpful.
  • Doramectin: 600ug/kg once weekly for five weeks to 23 weeks produced a cure in 10 out of 23 patients.

Demodicosis, whether it is juvenile- or adult-onset, is a serious disease that requires aggressive therapy. Treatment of the accompanying bacterial pyoderma is advisable and no steroids should be used. In adult-onset demodicosis, particularly in patients that have not been on steroids, a search for an underlying disease should be undertaken. Choosing which therapy is suitable for the patient and the owner is essential since contraindications for therapy exist not only for the patient, but in the case of amitraz dips, for the owner.

Alice Jeromin
Dr. Jeromin is a pharmacist and veterinary dermatologist in private practice in Cleveland, Ohio. She is a 1989 graduate of The Ohio State University College of Veterinary Medicine and an adjunct professor at Case Western Reserve University's College of Medicine in Cleveland.


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