I have a 4 yr old boxer. She was diagnosed with epilepsy when she was 1 1/2. She is currently being treated with pheonobarital. She is having break thru seizures and they are getting more frequent and lasting longer. Her vet keeps uping her dosage but that does not seem to help. She is currently taking 240 mg a day. My fear is she is going to max out on her medication quickly and we will not be able to do anything else for her. Does anyone know how high her dosage can go before it no longer works?