The medical records of 50 dogs that exhibited generalized convulsive tonic-clonic (GCTC) status epilepticus (SE) were reviewed and compared with the records of 50 dogs that exhibited non-SE GCTC seizures. The mean age, bodyweight and gender of the patients in both groups were not significantly different. Dogs in the non-SE group were two times more likely to be an idiopathic epileptic than to have secondary epileptic seizures. The SE group was more likely to have abnormalities on cerebrospinal fluid analysis, but not more likely to have abnormalities detected on computed tomography, when compared with the non-SE group. SE was 1·57 times more likely if the cause for the seizures was secondary or reactive epilepsy rather than idiopathic or primary epilepsy. In conclusion, dogs that exhibit SE should be thoroughly investigated for secondary causes.