Na2 ethylenediaminetetraacetic acid retention enema in dogs. Biochemical and histological response.

1. The use of Na2 EDTA in a per rectal lavage may facilitate cell harvesting for colonic cytology. So the effect of a Na2 EDTA 0.5% retention enema on serum electrolytes, kidney function tests and blood clotting mechanism as well as its direct effect on colonic mucosa, was evaluated in dogs. 2. The results were compared to a control study with a normal saline enema. 3. Blood samples and colonic biopsies were obtained at four time points. 4. A statistically significant decrease in serum calcium levels reaching a maximum 2 day post experiment, and increase in serum phosphorous and prolongation of prothrombin time at 2 hr post-experiment, were noted. 5. The perturbations were still within normal physiological limits for dogs, and no clinical manifestations of either hypocalcemia nor bleeding tendency occurred. 6. All other parameters evaluated did not change significantly at the examined time points. 7. Light microscopy examination of the colonic mucosa in the experimental group was not different from that of the control study. 8. Na2 EDTA may be used in retention enemas without significant clinical side effects.