For determining the variations of haematological parameters and of serum CK and LDH activities induced by digoxin intoxication in dogs, 24 healthy dogs were used in this study and were randomly divided into 2 equal group: in the group 1 (acute intoxication) dogs received an unique i.v. injection of 0.15 mg/kg digoxin, haematological parameters were determined one day before the treatment and during the 4 consecutive days after the injection while serum enzyme activities were measured at 12, 24, 48 and 72 hours after. In the group 2 (sub acute intoxication), animals received 3 intravenous digoxin injections on day 1 (50 mu g/kg 2 times then 25 mu g/kg), then they were treated by 25 mu g/kg digoxin i.v. once a day for 6 consecutive days. Haematological and biochemical parameters were assessed one day before and on Days 1, 3, 5, 7, 9, 11 and 15 after the first injection. Whereas haematological parameters remained relatively constant according to time and to the digoxin administration schedule, both digoxin treatments have induced significant increases of serum CK and LDH activities. During acute intoxication, CK variations were particularly intense whereas LDH activities were transiently altered (between 12 and 24 hours). By contrast, LDH activities gradually and significantly increased from the Day 5 to the Day 11 in the group 2 and CK activities were only significantly elevated on Day 11: LDH may be a more sensitive marker than CK in the situation of sub acute poisoning.