316 DISEASES/DISORDERS
Expected Course and Prognosis
Long-term prognosis: varies, depending on the severity.
Minimal disease: prognosis good; tends to resolve spontaneously with no evidence of
scarring.
Mild to moderate disease: tends to eventually resolve spontaneously, usually with
residual scarring.
Severe disease: poor prognosis for long-term survival; dermatitis and myositis are
severe and lifelong; may lead to crippling lameness and/or recurrent aspiration pneu-
monia from megaesophagus.Associated Conditions
Vesicular cutaneous lupus erythematosus (idiopathic ulcerative dermatosis) of Shet-
land sheepdogs and collies: poorly understood disease; described in adult collies and
Shetland sheepdogs; characterized by well-demarcated serpiginous ulcers in the inter-
triginous areas of the groin and axillae; may occur alone or concurrently with der-
matomyositis; originally considered a subgroup of dermatomyositis; likely a variant
of lupus erythematosus.Pregnancy
Disease is inheritable; do not breed affected dogs.
Pregnancy exacerbates clinical symptoms.
Fig. 20.1.Dermatomyositis in a collie mix with lesions of alopecia, crusting, and scarring of the face.