Serum complement level in dogs with neoplastic disease.

The hemolytic reactivity of complement obtained from 119 dogs with and without cancer has been determined. Dogs with cancer were divided retrospectively, into 2 groups--dogs with lymphosarcoma (37) and dogs with malignant neoplasms other than lymphosarcoma (31). Normal dogs (21) served as a control group. Also, for comparison, complement reactivity was determined on sera from a 4th group composed of a limited number (30) of dogs with serious systemic illnesses other than neoplasia. There was no significant difference among means for hemolytic complement reactivity of the 4 groups. However, when the dispersion of hemolytic complement values within each group of abnormal dogs was compared with that of normal dogs by variance ratio testing, it was found that all abnormal groups had highly significant greater variances than did normal dogs.