Small Animal Dermatology, 3rd edition

CHAPTER 42 SARCOPTID MITES 637

THERAPEUTICS

 Scabicidal rinses: the entire dog must be treated; treatment failures often linked to

owner’s reluctance to apply rinse to the patient’s face and ears; swimming and bathing

are prohibited between treatments.

 Cheyletiellaspp. andOtodectes cynotis: all in-contact dogs, cats, rabbits should be

treated, even those with no clinical signs; asymptomatic carriers possible.

 Sarcoptes scabieiandNotoedres cati:all in-contact dogs or cats (respectively) should

be treated, even those with no clinical signs; asymptomatic carriers possible.

 Thoroughly clean and treat the environment; mites can survive for up to 3 weeks off

a host animal (depending on species, temperature, and humidity).

 Corticosteroids may be used concurrently with miticidal therapy; immunomodula-

tory drugs administered without miticidal therapy (prior to diagnosis) may cause

increased pruritus and be associated with a higher rate of positive skin scrapings.

Therapeutic Options

 Avermectins:
Macrocyclic lactone with GABA agonist activity
Ivermectin: 0.2–0.4 mg/kg PO or by subcutaneous injection every 1–2 weeks for

4 treatments:

Systemic use contraindicated in collies, Shetland sheepdogs, Australian

shepherds, Old English sheepdogs, white German shepherds, long-haired

whippets, greyhounds, silken windhound, other herding breeds, and

crosses with these breeds; sensitivity derived from a deletion mutation of

the multidrug-resistant gene (ABCB1); see demodicosis treatment

Toxicity seen as hypersalivation, mydriasis, tremors, depression, ataxia,

blindness

Intravenous lipid emulsion therapy has shown success in the treatment of

ivermectin toxicosis

Do not use with Spinosad-containing flea control products; enhances toxi-

city of ivermectin

Ivermectin topical:Otodectes cynotis

Selamectin: 6–12 mg/kg applied topically every 2 weeks for 3–4 treatments (dogs

and cats)

Moxidectin: 200 mg/kg PO or by subcutaneous injection every 2 weeks for two

treatments

Imidacloprid 10% with moxidectin 1% topical: applied monthly for two treat-

ments;Otodectes cynotis

Milbemycin: 0.75 mg/kg PO q24h or 2 mg/kg PO weekly for 3–4 treatments

(dogs)

Milbemycin 0.1% topical:Otodectes cynotis

Doramectin: 0.2–25 mg/kg PO or by subcutaneous injection weekly for two

treatments.