Chapter 58 Diseases of the Pinna
The pinna is a mobile structure designed to localize and collect sound waves and transmit them to the tympanic membrane. The pinna has vastly different breed conformations in the dog, while in the cat; there is very little breed variation. The auricular cartilage expands to form the pinna, with the skin of the concave portion of the pinna tightly adherent to this cartilage. The cartilage of the pinna becomes funnel shaped at the opening of the external ear canal.
Table 58-1 DERMATOSES OF THE PINNA
Affected Site(s) | Disease | Clinical Lesions Found on Pinna |
---|---|---|
Pinna only | ||
Canine eosinophilic pinnal folliculitis | Erythema, papules, crusts | |
Ear margin seborrhea | Scale, fissures | |
Fly bite dermatitis | Ulcers, crusts, erythema, alopecia | |
Proliferative thrombovascular necrosis of the ear pinnae | Ulcers, scale, hyperpigmentation | |
Pinna and other body areas | ||
Actinic keratoses | Erythema, hyperkeratosis, crusts, hyperpigmented plaques | |
Arteriovenous fistula | Edema | |
Atopic dermatitis | Erythema | |
Canine demodicosis | Erythema, papules, scale, alopecia, crusts | |
Canine sarcoptic mange | Erythema, papules, crusts, scale, alopecia, excoriations | |
Contact dermatitis | Erythema, macules, papules, erosions, ulcers | |
Cutaneous adverse food reaction | Erythema | |
Dermatomyositis | Alopecia, erythema, scale, crusts, ulcers, scars | |
Dermatophytosis | Erythema, alopecia, papules, pustules, crusts | |
Discoid lupus erythematosus | Alopecia, crusts, ulcers | |
Feline demodicosis | Erythema, papules, scale, alopecia, crusts | |
Feline sarcoptic mange | Erythema, papules, crusts, scale, alopecia, excoriations | |
Frostbite | Ulcers, necrosis | |
Hereditary lupoid dermatosis of German short-haired pointers | Scale, crusts | |
Juvenile cellulitis | Papules, pustules, crusts | |
Malassezia pachydermatis | Erythema, alopecia, scale, crusts, hyperpigmentation lichenification | |
Melanoderma and alopecia in Yorkshire terriers | Alopecia, hyperpigmentation | |
Pattern baldness | Alopecia, hyperpigmentation | |
Pemphigus erythematosus | Erythema, scale, papules, pustules, alopecia, crusts | |
Pemphigus foliaceus | Erythema, scale, papules, pustules, alopecia, crusts | |
Psoriasiform-lichenoid dermatosis of springer spaniels | Erythema, hyperpigmentation, plaques, papules | |
Sebaceous adenitis | Papules, alopecia, scale, follicular casts | |
Systemic lupus erythematosus | Alopecia, crusts, ulcers | |
Vasculitis | Erythema, alopecia, ulcers, crusts, necrosis | |
Zinc-responsive dermatosis | Erythema, scale, crust, hyperkeratotic plaques |
INFECTIOUS DISEASES
Dermatophytosis (also see Chapter 42)
Diagnosis
Treatment
Clinical Signs
Diagnosis
Parasitic Diseases
Sarcoptic Mange (also see Chapter 44)
Clinical Signs
Diagnosis
Pinnal pedal scratch reflex (vigorously rubbing the tip of one ear flap on the base of the ear with a response of a scratching movement of the ipsilateral hind leg) for the diagnosis of sarcoptic mange in the dog was found to have a sensitivity and specificity of 81.8% and 93.8%, respectively.