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EAR DISEASES OF THE DOG AND CAT
General clinical examination
Further investigations
Progress
Examination detected no abnormality.
The scrapings taken proved negative for Sarcoptes scabiei and Demodex canis. Cytology of a pustule from the glabrous part of the abdomen revealed degenerate neutrophils with intracellular and extracellular cocci. Ear cytology detected Malassezia.
Fifteenday review appointment: The superfi cial pyoderma was resolving and there were no new papules or pustules. The pruritus was still very intense. It was recommended continued treatment and another review in 15 days.
Dermatological clinical examination The lesions present were: alopecia, erythe ma, papules, pustules, epidermal collarettes, crusts, hyperpigmentation, hyperkeratosis and lichenification. These lesions were found mainly on the face, pinnae, cubital fossae, axillae, interdigital spaces and the entire ven tral aspect of the trunk (Figs. 1, 2 and 3). The pinnae displayed intense erythema and lesions caused by the chronic nature of the condition (hyperkeratosis, lichenification). Otos copic inspection revealed bilateral erythemato ceruminous otitis. The pruritus was so intense that the animal scratched itself even on the consulting table.
Differential diagnosis Based on the animal’s highly intense pruritus, the distribution of the lesions, and the pre sence of erythematoceruminous otitis, the first things to consider were allergic disease (atopic dermatitis, food allergy, FAD) and sar coptic mange. Differential diagnosis also had to include pruritic superficial pyoderma, sec ondary to demodicosis or otherwise. A diag nosis of sarcoptic mange was considered less likely than allergic disease, because the two dogs living with the patient had no pru ritus or skin lesions, and nor did the owners.
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Food allergy-associated bilateral otitis externa in a dog
CASE STUDIES
By then, the lesions of superficial pyo derma had disappeared, but the pruritus and associated lesions persisted. The ear ery thema had subsided greatly. It was continued the oral antibiotic treatment and ear drops for just another 15 days, and the rest of the treatment as before. At the same time, it was
Diagnosis Probable allergic condition (atopic dermatitis, food allergy).
Treatment It was began treatment for the superficial pyoderma with: Cefalexin: 25 mg/kg b.i.d., treatment not to stop until veterinary review in 15 days. Essential fatty acids: 3 capsules s.i.d. for 2 months. Twiceweekly baths with antiseptic, anti seborrhoeic shampoo, to be massaged into the affected areas, left in contact for 10 minutes, then rinsed, followed by dry ing in the sun and/or with towels.
Figure 1. Alopecia, erythema, hyperkeratosis and lichenification around the eyes, on the muzzle and on the pinna.
Figure 2. Generalised lesions: alopecia, erythema and hyperpigmentation.
Figure 3. Marked erythema on the pinnae.
Figure 4. Chronic otitis. Photograph courtesy of Dr Cristeta Fraile.
And for the otitis: Ear cleanser. Both ears cleaned before starting eardrop treatment. Gentamicin, betamethasone and clotri mazole: 6 drops in each ear canal, twice daily, with vigorous massage after each application.
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