Canine Epilepsy: What It Is, What It Isn’t and What to Do About It First published in Double Helix Network News, Summer 2002 by C.A. Sharp Lonny woke up to the bed shaking. Having grown up in California, his first groggy thought was, "Earthquake!" He sat up, heart pounding and awake enough to remember he lived in Kansas now. But the bed continued to shake. Oso, his best buddy and beautiful black tri Aussie lay moaning beside him. Something smelled. Lonny spoke to Oso to reassure him as he fumbled for the bedside light. It flashed on. Beside him Oso convulsed in a seizure. His eyes were glazed, his body stiff. Oso’s legs flailed and his jaws snapped at nothing. Urine and feces stained the bedspread. Lonny's heart thudded in his chest and his eyes blurred with tears. What was happening to his wonderful dog? He scrambled out of bed. Oso lay near the opposite edge, in danger falling off and striking a dresser. Lonny pulled on the bedspread to move Oso into the middle of the mattress. He wanted so badly to hold Oso and comfort him, but didn’t dare touch him because of the blindly snapping jaws. Unable to do anything else, Lonny spoke softly to his friend until Oso's seizure stopped. Neither Lonny nor Oso are real, however there are too many Australian Shepherds like Oso and too many people like Lonny who must regularly deal with the horror of watching a beloved dog suffer repeated epileptic seizures. In the 1980s, epilepsy was only occasionally noted in the breed, but today it is one of the Aussie’s most frequent inherited diseases. It is easy to misdiagnose. Treatment is available, but not without side effects or the risk that the disease will not respond. Not only are the genetics of it so far unknown, but most affected dogs will not develop the disease until adulthood making it difficult to breed away from. It scares breeders so much that too many of them refuse to acknowledge it and may even lie about whether it has occurred in their lines, further complicating efforts to reduce its frequency. Inherited epilepsy, also called "primary" or "idiopathic" epilepsy, has long been recognized as a canine disease. It is seen in both purebred and mix-breed dogs, but some breeds, like the Aussie, have a much higher incidence than that seen in dogs as a whole. This is the result of the inbreeding inherent in the development and maintenance of any purebred population. The founders of any given breed will have only a subset of the genes—good and bad—present in the canine species. Selection over generations for desired traits will limit that gene pool further and not all the genes retained will be for desirable traits. If, at some point in a breed’s history a particular sire or line of dogs becomes predominant, inherited problems may start to arise seemingly out of nowhere. Attempts to concentrate the desirable genes of the select individuals, can inadvertently bring together whatever undesirable genes are present. Inherited epilepsy is often called "idiopathic," which means of unknown cause. The terminology is no longer accurate but was developed at a time when no one realized that genes could cause the disease. Primary epilepsy is perhaps a better term because it indicated that the epilepsy is not caused by some other factor. Epilepsy is a seizure disorder. Both epilepsy and individual seizures can be caused by a variety of things: Head injury, toxic exposure, infections, fever, body chemistry imbalances and brain disease, to name a few. When a dog has a seizure, the veterinarian’s task is to identify and treat the cause. A detailed history will be taken to determine whether anything has happened to the dog that might cause seizures or whether it might be suffering from some other disease. The vet will ask about what the dog has done recently, where it has been, what medications it is taking, whether it showed signs of illness other than the seizure. If the dog was not presented in a seizure state, as is often the case, the vet will ask for a detailed description of the seizures—what the dog did before, during and after, how often the seizures occur and how severe they are. Tests will be run to make sure blood counts and body chemistry are normal. If an injury is suspected, x-rays may be taken. An MRI might be done to see whether there is any damage or disease in the brain. If a cause is found, the dog will be treated for that problem. If permanent brain damage has not been done, treatment of the causative injury or disease will eliminate the seizures. If there is brain damage, the seizures may continue and require ongoing treatment. Such a dog would have secondary epilepsy—epilepsy brought about by an identified cause. If a dog has inherited epilepsy, all tests will be negative. At this time there is no positive test for this disease. It is a diagnosis of exclusion—the ruling-out of all other reasonable possibilities. Dogs with inherited epilepsy will continue to have seizures at intervals. The intervals may be as long as weeks to months or as short as once or several times in a single day. The dog cannot be cured. It will probably have seizures for the rest of its life. The seizures may cause cumulative damage to the affected area of the brain. And seizures sometimes kill. Because of the risk of cumulative damage from repeated seizures, medication may be necessary. There are drugs that help control seizures and any dog that is seizing more frequently than once a month probably should be medicated. Fortunately the medications are inexpensive, but they do have serious side effects. The vet must determine which drug or combination of drugs is best for a particular dog. In many cases, the vet will start with a larger dose to get the seizures under control. Then, over time, the medication will be adjusted to a minimum effective dose. Even medicated, epileptic dogs will continue to seize. The point of treatment is to keep it from happening too often. Medications may need to be adjusted from time to time, and every epileptic dog should be seen by a vet on a regular basis to monitor the epilepsy as well as drug side effects. Not every dog will respond to medication. Some may respond for a while, then cease to do so. Seizures often develop a pattern, not just in frequency but in what triggers them. Owners of epileptic dogs should keep a seizure log, noting the date, time, circumstances and severity of the seizure for their own information as well as their vet’s. Some dogs will seize at night while sleeping, others may have a seizure when engaged in particular (often exciting) activities. Knowing when your dog is likely to seize can help you prevent him from injuring himself during a seizure. When a seizure starts, other animals and children should be removed from the immediate area. Remove anything nearby that might be damaged or harm the dog if he strikes against it. Speak to the dog in soothing, calm tones. Do not touch the dog or put your hands in or around the dog’s mouth as it might accidentally bite you. Seizing dogs may react to any touch by snapping and can cause severe injury. Most dogs will be woozy and disoriented after a seizure. This may last a couple hours or a few days. Make sure the dog has a quiet place to rest and discourage other animals or children from bothering the dog until it is feeling normal again. If you do not feel that the dog is recovering properly, contact your vet. The vet should be contacted as soon as possible after a seizure to report the circumstances. A visit may or may not be necessary at that point, but if the dog has a second seizure it should definitely go to the vet for exam and testing. Living with epilepsy is distressing. There are groups available to help. (See references at end of article). Sometimes talking with other people who are dealing with the same problem you are is a big help. They’ve been there and they know exactly what you are going through. They may also be able to offer you tips that will help make your life and your dog’s easier as you deal with the disease. Epilepsy presents one set of problems to a dog owner and another to a breeder. It is a terrible disease and not something any breeder wants to produce, but avoiding it can be difficult. We don’t know exactly how it is passed from one generation to the next. Dogs may not develop the disease until they are old enough that they may already have offspring. Failure by some to disclose information can make it impossible for others with related dogs to take effective steps to limit risk of producing epileptic dogs. While primary epilepsy is now recognized as inherited, the mode of inheritance is not yet known. It is possible that there are several genetically distinct types of epilepsy, though any one breed will likely have only a single type. In Australian Shepherds, it is clearly not dominant or one would see it following clear lines from parent to offspring generation after generation. A sex-linked condition would result in many more affected males than females, which is not the case. This leaves either recessive or polygenic modes of inheritance. In either case, a healthy parent can produce affected offspring and both parents must be carriers. Because this disease is so devastating to the owner as well as the affected dog and because it can sometimes kill, the author strongly discourages the continued use for breeding of any dog that is a first-step relative of an epileptic dog. This would include parents, siblings and offspring. More distant relatives will need to be bred with care because they have a potential for carrying epilepsy genes. The closer they are related to the affected dog, the greater the risk. Relatives of epileptic dogs are also at risk for having epilepsy themselves. If such a dog is intended for breeding, one should not do so until it is at least three or four years old. Most affected dogs will begin to have seizures around two years of age. Aussies as young as 8 months old have been diagnosed with inherited epilepsy. Dogs over four years of age will sometimes develop the disease, but this is relatively rare. [NOTE: In Aussies, baby puppies do not exhibit signs of primary epilepsy. If a young puppy is having seizures there is some other cause.] If this disease is to be controlled in our breed, people need to start coming out of the closet and admitting it happened. And when they do, the rest of us need to start being supportive of these people instead of shunning them and their dogs. The more open information is exchanged among breeders, the better chance breeders will have to avoid breeding two high-risk dogs together. Knowing the mode of inheritance and being able to positively identify carriers would be a great boon for breeders. But discovering the mode of inheritance and developing a screening test requires research. Research requires data on affected dogs and their near relatives. There is research currently underway on canine epilepsy in a variety of breeds. So far, the only project to come close to identifying genes is one being conducted at the University of California, Davis, on the Belgian sheep dog breeds. In those breeds (which are considered a single breed with coat and color varieties in most countries outside the US) at least three genes are involved, one of which is of major impact. Research continues in an effort to locate those genes and develop a DNA screening test. But this work may not apply to Aussies, since they are at best distantly related to the Belgian breeds. For Australian Shepherds, the mode of inheritance remains a mystery. There are currently two research projects that are looking at the disease in the breed. One is conducted by VetGen, LLP, a commercial laboratory working in association with the University of Michigan. The other is at the University of Missouri. Both need DNA samples from family groups including both affected and non-affected individuals. A "family" includes at a minimum affected dog(s), plus parents and siblings. (See "Resources" below for how to contact these studies.) Unfortunately, neither project has enough data to move forward, largely due to lack of cooperation on the part of breeders. The owner of an epileptic dog is often not only willing but anxious to do anything possible to prevent this happening to others, but the owner rarely owns his dog’s entire family. Those who have the parents and siblings of the dog must also assist. Without such cooperation, the research and any hope for a screening test is stalled. Researchers at Florida State University who are investigating epilepsy in Standard Poodles wrote in an article about their project, "All the scientists in the world cannot find the genes that are responsible for diseases in dogs without the information possessed by owners and breeders." With a DNA screening test, especially a direct gene test, breeders would know which dogs will develop the disease so they will not be bred. Knowing which are carriers will prevent any two carriers from being bred together, much as we avoid breeding merles together because we don’t want to produce blind and deaf pups. Preference can be given to dogs that are not carriers and the frequency of the genes for epilepsy gradually reduced without sacrificing the good qualities possessed by carrier dogs. A day may come when there are no more Osos and the Lonnys of the world will no longer have to kneel beside their stricken dogs waiting for the seizure to end. But before we can get there, breeders need to make the control of epilepsy a major priority, supporting the owners of affected dogs and working with vets and researchers toward genetic control of the disease. References: Canine Epilepsy Network, University if Missouri, Columbia www.canine-epilepsy.com General information as well as information on their epilepsy study, links, how to submit data and a discussion forum. You can also contact Research Coordinator Liz Hansen at hansenl@Missouri.edu or 573-884-3712. Canine Epilepsy Resource Center www.canine-epilepsy.com offers resources. Articles, links to related sites and the Epil-K9 discussion list. K-9 Epilepsy Discussion List www.schips-r-it.com/k9epi.html VetGen, LLP For current information on VetGen’s epilepsy research go to www.vetgen.com/epilepsy.html or contact Research Coordinator Cheryl Hogue at healthydog@vetgen.com or 800-483-8436