Systemic autoimmune disease and concurrent nematode infection in a dog.

Systemic lupus erythematosus was diagnosed in a dog with concurrent nematode infection. The clinical signs of disease were unusually severe and included multiple neurologic deficits, polyarthritis, and weight loss. The dog was thrombocytopenic, and serotest results included positive lupus erythematosus test, positive rheumatoid factor test, positive antinuclear antibody test, hypergammaglobulinemia, and high platelet-associated IgG concentration. After treatment of hookworm, whipworm, and heartworm infections concurrently with corticosteroid and empiric treatment, the dog's condition improved. However, 10 days later, cyclophosphamide administration was necessary for continued immunosuppression. The dog was euthanatized because of progressive deterioration and development of canine coronavirus diarrhea. Serotest data generated from the dog's serum obtained at the time of referral suggested that autoantibodies and circulating immune complexes may have included IgE isotypes.