Here is some info I found:
Lionheads and Seizures
My exploration into this question has revealed that Idiopathic Epilepsy is a problem in certain bloodlines of Dwarf rabbits in Europe and to a lessor extent in Dwarf Rabbits in England. Since the Spring issue of the English Lionhead Club Newsletter includes a statement that it is now time for the breeders in England to “STOP crossing to other breeds to introduce additional colors”, it is logical to assume the Dwarf Rabbit has been used in breeding Lionheads in England.
The repeated stories of seizures in Lionheads in the United States fit the description of Idiopathic Epilepsy.
They can not be attributed to injury or poison.
They do not result in the direct death of the rabbit.
They most often onset with no warning and manifest in grand mall form.
The rabbit recovers from the seizure to just have another days, weeks or even months latter.
The stories are varied but all fit the framework of Idiopathic Epilepsy. A young Lionhead has his first seizure when 8 weeks old at weaning. One doe seized when she was placed with a buck for breeding. I also just had a nice buck have a horrible seizure after a servicing a doe. (He had successfully been used before). Another young Lionhead (about 5 months old) had it’s first seizure when being groomed for a show.
Most often owners simply say they were in the rabbitry doing chores when suddenly the Lionhead was thrashing in it’s cage. The rabbits all recover and are able to resume normal activity. Nothing in any of the reports would make me think of poisoning or injury. (Some breeders think this is wry neck – it is not. WRY NECK DOES NOT COME ON SUDDENLY LAST MINUTES AND CLEAR UP)
The susceptibility for generating an epileptic seizure varies within the individual. Some may have a lower threshold for epileptic seizures and are therefore more likely to develop this condition. Though this a genetic condition it can take time to manifest. Often seizures are be triggered by external stimulation.
TREATMENT
There is no true cure as this condition is genetically encoded in the rabbit’s makeup. We can offer support. Since over all seizures are uncommon in rabbits, it can be difficult to find extensive information on treatment or a Veterinarian who has the knowledge to help a rabbit owner deal wit this problem.
If you find yourself with a Lionhead pet who has seizures there are some things the owner can so. Control of the environment can be important as often bright light and over handling will induce a seizure. Seizures can be triggered by external stimulation.
If you find yourself confronted by a Lionhead who is haveing a seizure, often simply placing the rabbit in a SMALL cage enclosure that is dark, cool and quiet is all that is needed. Remember it is always wise to contact your veteranary for support and information.
If the seizure should last for any length of time it is important to get veterinary help at RIGHT AWAY. The act of seizing can raise the body temperature to dangerous levels. Remember when handling a seizing Lionhead they no longer have any idea of where they are or who you are. Support of the back is very important if you must lift the rabbit to move it to a safe place.
If you do find yourself with an Epileptic Lionhead this information may be of help to your veterinarian. To stop seizures, diazepam (1-2 mg/kg IV, IM) or midazolam (1-2 mg/kg IV, IM) should be given immediately.
WE MUST NOT HIDE THE PROBLEM.
This breed is very young and we can beat this thing if we all work together. Let potential buyers know. If a propective buyer should decide the breed is what they want that should be fine with all of us. We love our breed and we are willing to tackle and solve this problem, but not everyone else is. People who are buying Lionheads need to know. They need to be aware that this is a potential problem so they will be prepared if it should happen to their Lionhead.