CHAPTER 20 DERMATOMYOSITIS, CANINE FAMILIAL 315
Pentoxifylline: 10–20 mg/kg with food PO BID to TID: proposed to increase microvas-
cular blood flow and tissue oxygenation by lowering blood viscosity, inhibit platelet
aggregation, increase RBC deformability, and reduce serum fibrinogen levels; benefi-
cial in some dogs.Cyclosporine, modified: 5–10 mg/kg PO q24h as an intitial dose and then tapered;
reserved for severe cases with an active inflammatory component.
Precautions/Interactions
Pentoxifylline should not be used in dogs that are sensitive to methylxanthine deriva-
tives (e.g., theophylline).
Pentoxifylline can cause gastric irritation; animals with prolonged clotting times and
those receiving anticoagulant therapy should be monitored carefully.
Glucocorticoids: discuss possible side effects with the owner.
Cyclosporine: monitor serum chemistry for potential side effects.
COMMENTS
Discuss the hereditary nature of the disease.
Note that affected dogs should not be bred.
Inform owner that the disease is not curable, although spontaneous resolution can
occur.
Discuss prognosis and possible complications, especially in severely affected dogs.
Advise that medications may not help.
Client Education
Prevention/avoidance.
Minimize trauma and exposure to sunlight.
Spay intact females to prevent estrus, parturition, and lactation (all precipitating
causes of active dermatomyositis).
Do not breed affected animals.
Possible Complications
Secondary pyoderma.
Mild to moderate disease: residual foci of alopecia, hypopigmentation, and hyperpig-
mentation in areas of previously active skin lesions; occurs most frequently on the
bridge of the nose and around the eyes.Severe disease: extensive scarring; trouble chewing, drinking, and swallowing if the
masticatory and esophageal muscles are involved; megaesophagus may develop, pre-
disposing the dog to aspiration pneumonia.Generalized myositis: growth may be stunted.