Hi Sir or Madam,
Diazepam and valium are indeed the same drug. The human formulation is the same as the drug given to dogs. I can not advise you to give any prescription drug to your dog. If your dog has been prescribed valium by your vet, then your dog should be able to take the same dosage of diazepam with no problems. You can read about precautions, dosages and usage information here:
You can read about clomipramine here:
Seizures can be caused by a large number of different things including no known reason which are called idiopathic. You can read about seizures here:
Given the number of different causes for seizures it is unlikely that the medcation is to blame. I hope this information is helpful to you.