An epidemiologic study of households exposed to canine systemic lupus erythematosus.

To determine whether exposure to canine lupus is a risk for human lupus, we studied 83 members of 23 households exposed to 19 dogs with high titer antinuclear antibodies and compared these contact households to 50 members of 18 control households matched for dog age, sex, and primary veterinarian. No differences were found between contacts and controls in titer of antinuclear, antiDNA, antiRNA, and antilymphocyte antibodies, frequency of positive rheumatoid factor, or elevated serum immunoglobulins. Further analysis of subgroups by age, sex, and intensity of dog exposure did not reveal any serologic differences between contacts and controls. No cases of lupus were identified in either group. Three contact households and no controls reported a family history (remote from the household) of lupus. This study did not detect any clinical or serologic effect of human household exposure to dogs with high titer antinuclear antibodies.