For dogs with localized (mild to moderate) disease, weekly administration of topical chlorhexidine or benzoyl peroxide shampoo
is recommended. Many dogs' clinical signs will resolve with this treatment alone.
In patients with disease progression or generalized disease, a similar topical therapy given weekly or even twice weekly is
recommended. When evidence of secondary bacterial infection is present, perform cytology and bacterial culture and sensitivity,
and give the patient appropriate topical or systemic antimicrobial therapy. If the disease persists or progresses, miticidal
therapy is necessary.
When treating a patient with demodicosis, you must first consider clinical presentation, local legalities, product availability,
and owner finances. Regardless of treatment selection, patients requiring miticidal therapy should be neutered. In fact, the
committee states that "ideally, all dogs with demodicosis should be removed from the breeding pool."
Of the mite treatments available, weekly amitraz rinses and daily oral macrocyclic lactones (milbemycin oxime, ivermectin,
and moxidectin) have demonstrated efficacy in the treatment of canine demodicosis. Adverse effects are associated with these
oral medications in sensitive dogs, especially herding breeds. So it is recommended that the dose be gradually increased until
the calculated therapeutic dose is reached. For mild disease, weekly topical (spot-on) moxidectin with imidacloprid can be
effective. Examine patients receiving miticidal therapy monthly (three to five skin scraping samples per visit, including
the most severe lesions and any new lesions), and change treatment if clinical signs or mite numbers are not improving.
Once all skin scraping results are negative for mites, consider treatment for four to eight more weeks (one month after the
second consecutive negative set of scrapings). Treatment should not end with the resolution of clinical signs. Monitor patients
that have been treated for generalized demodicosis for recurrence during the first year after remission, and avoid long-term
glucocorticoid therapy or any other immunosuppression if possible.
The prognosis is good for dogs with demodicosis, but dogs with persistent underlying immunocompromising conditions may need
long-term therapy to maintain clinical remission.
Mueller RS, Bensignor E, Ferrer L, et al. Treatment of demodicosis in dogs: 2011 clinical practice guidelines. Vet Dermatol 2012;23(2):86-98.
A full-text PDF of the guidelines is available at onlinelibrary.wiley.com/doi/10.1111/j.1365-3164.2011.01026.x/pdf
This "Hot Literature" update was provided by Avi Blake, DVM, a freelance technical editor and writer in Eudora, Kan.