Introduction
- Cause : Otodectes cynotis
- large, white, free-moving psoroptid mites which live on surface or epithelial lining of ear canal and occasionally skin. - Signs : may initiate otitis externa but remain undetected.
- Diagnosis : identification of mites.
- Treatment : ear canal cleansing, otic ectoparasiticides.
- Prognosis : excellent.
Diagnosis
Clinical signs
- Erythema and swelling.
- Vasodilation.
- Dry coffee grounds appearance of otic exudate.
- Aural hematoma.
- Acute moist dermatitis face.
- Pruritus and skin lesions in other body locations.
- Aural hemorrhage.
Diagnosis
Differential diagnosis
- All other causes of otitis externa .
Sequelae
Prognosis
- Excellent providing no other predisposing, primary or perpetuating factors for otitis externa .
Expected response to treatment
- Regression of clinical signs.
- No mites seen on otoscopic examination after 3 weeks.
Reasons for treatment failure
- Inadequate treatment of patient or in-contacts.
- Predisposing, primary and perpetuating factors for otitis externa not identified or treated.
Sources
Publications
Refereed papers
- Engelen M A C M (2000) Efficacy on non-acaracidal containing otic preparations in the treatment of otoacariasis in dogs and cats. Vet Rec 147 , 567-569.
- Paradis M (1998) Ivermectin in small animal dermatology Part II. Extralabel applications. Comp Cont Ed Prac Vet 20 , 459-469.
- Little C J L (1996) A clinicians approach to the investigation of otitis externa. In Practice 18 , 9-16.
- Little C J L (1996) Medical treatment of otitis externa in the dog and cat. In Practice 18 , 66-71.
- Foley R H (1991) Parasitic mites of dogs and cats. Comp Cont Ed Prac Vet 13 , 783-801.
- Smith E K (1988) How to detect common skin mites through skin scrapings. Vet Med 83 , 165-170.
- Powell M B, Weisbroth S H, Roth L & Wilhelmsen C (1980) Reaginic hypersensitivity in Otodectes cynotis infestation in cats and mode of mite feeding. Am J Vet Res 41 , 877.
- Herwick P P (1978) Lesions caused by canine ear mites. Arch Dermetol 114 , 130.
- Rose W P (1976) Otitis externa - otoacariasis. Vet Med Sm Anim Clin 73 , 427.
Other sources of information
- Morrelo K A & Mason I S (1995) Handbook of Small Animal Dermatology. Pergamon Press. pp 259-267 (Concise for quick reference).
- Muller G H et al(1995) Muller and Kirk's Small Animal Dermatology. 5th edn. Philadelphia: W B Saunders. pp 970-987 (Detailed dermatology text book for in-depth reading).
- Merchant S & Griffin C (1994) The 1994 Ear Care Symposium, Otitis Externa, the 21 Most Commonly Asked Questions. Veterinary Learning Systems Co Inc. (Practical advice on treatment).
- Griffin C E, Kwochka K W & MacDonald J M (1993) Current Veterinary Dermatology - TheScience and Art of Therapy. St Louis: Mosby Year Book. pp 245-262 (Well presented dermatology text book with good treatment plans).
- McKeever P J (1993) In: Manual of Small Animal Dermatology. P H Locke, R G Harvey & I S Mason (eds). Cheltenham: BSAVA. pp131-140 (Concise for quick reference).
- Paradis M (1989) Ivermectin in small animal dermatology. In: Kirk R W Current Veterinary Therapy X - Small Animal Practice.Philadelphia: W B Saunders.
