From Darlene Stewart- Chairperson National Beagle Club of America Health and Genetics Committee
Epilepsy is a very sensitive subject in beagles. It is time we have a very open discussion about this problem in our breed. Since a week before the Nationals until now I have received 5 confirmed reports of affected beagles and two more pending confirmation. These reports are NOT from one beagle, one line or one kennel. They are divided among many recognizable names. There is MAJOR problem building in our breed. The risks are everywhere, no one is safe. We have to initiate honest communication about our beagles to try and stop the tsunami that is coming. Investigate the background of your beagles, ask about parents, grandparents. Have they produced any epileptic beagles? What about sibling of your beagle, have they produced any affected? Are there any affected in direct pedigree? Is it late onset, early onset, controlled with meds, what tests were done? Ask the same questions of any potential breeding partners for your beagle.
Support those that choose to come forward and be proactive in the discussion, instead of often isolating them. Don’t make excuses for seizures. If no reason is found then assume it is genetic in origin. Don’t ignore it, please.
One question I would suggest that everyone ask themselves is: IF a puppy owner informs you that their dearly loved pet is having seizures, can you honestly tell them you have done everything possible to breed away from risk factors?
Recommended articles to review:
THE ROAD TO HELL -- http://www.ashgi.org/home-page/genetics-info/epilepsy-other-neurological-issues/epilepsy/the-road-to-hell
THE LONG WINDING ROAD -- http://www.ashgi.org/home-page/genetics-info/epilepsy-other-neurological-issues/epilepsy/the-long-winding-road
WHAT’S THE BIG DEAL -- http://www.canine-epilepsy.com/Whats.html
is on a cliff, do we pull it back or push it off…the choice is ours.
Author: Deb Wigal DVM and Ruth Darlene Stewart -reviewed/approved by National Beagle Club Health and Genetics Committee
WHAT WE KNOW
A seizure is caused by an abnormal nerve
signal that results in a muscle response. There are many types of seizures,
majority involve some loss of consciousness. If you stood behind the dog and
called its name, most would be unable to respond.
1) Generalized - these are the type most people think of when they hear the word seizure. The dog will lose consciousness and get rigid. They may paddle and sometimes appear to be chewing. Many will salivate, urinate and or defecate
2) Petit Mal - Signs of this form are brief. Generally, you will see a very brief loss of consciousness, loss of muscle tone and maybe a blank stare. Even though these seizures do not appear to be as severe, the underlying cause is the same as generalized.
3) Simple Focal Seizures - The muscle movements occur in one area of the body. You may see facial twitches or muscle jerking in one area like a leg or twitching of the side. Your beagle may be alert and aware during this type. But these can progress to generalized seizures.
4) Complex Focal Seizures - These seizures are associated with strange, repetitive behaviors. Lip smacking or fly biting are common examples. Some dogs get very aggressive or vocal while others may hide abnormally.
5) Cluster - this is a term used when an animal has multiple seizures within a 24 hour period of time. These are considered very serious and need veterinary attention immediately.
6) Status Epilepticus - This is a continuous seizure that lasts 15- 30 minutes or more or multiple seizures that occur so close together that no return to normal consciousness occurs. These can be life threatening so immediate veterinary attention is needed.
Seizures can be caused by anything that
disrupts normal brain circuitry. There
are two types.
1) Secondary - This is a seizure caused by a known toxin, metabolic disturbance or possibly a previous brain injury/trauma. Numerous types of testing are needed to rule these in or out. These tests include a complete chemistry panel and CBC, thyroid, urine and stool. These tests can identify hypoglycemia or a possible liver shunt. If negative then an EEG as well as a CT or MRI should be performed to look for a structural brain lesion, such as a mass. Regular x-rays can only show us the bones of the skull, but not the soft tissue of the brain itself
2) Idiopathic (Primary) - This diagnosis means that there is no known cause for the seizures. This conclusion is reached after a full array of tests have been completed and they are negative. Most of these seizures are considered inherited. Close inspection of the dog’s pedigree may reveal affected relatives. Unfortunately this is the most common type that is diagnosed. Usually once on anti-seizure medication the seizure activity is well controlled.
AGE OF ONSET OF EPILEPSY
Most dogs will start to seizure somewhere between 18 months and 5 years of age (classic onset) although in beagles seizures have been known to occur as early as 3 months (early onset) and as late as 9 years (late onset). In beagles late onset seizures appear to be about as common as the classical form.Comments from Anita M. Oberbauer, Ph.D.-Professor and Department Chair ---Department of Animal Science, UC Davis (http://animalscience.ucdavis.edu/faculty/oberbauer/) concerning the three age groups noted in beagles:
“That does indeed sound like three distinct syndromes. And syndrome is likely the best adjective to describe it. We are finding in other breeds that epilepsy is highly polygenic and while it does track to particular lines, it is less than predictable. Furthermore, we have identified regions in that are associated with epilepsy in some breeds but not at all applicable in others yet there are some that do appear to be informative across breeds. Anecdotally when breeders do purposely breed away from so called "hot" (high risk) sires, the incidence does decline. That is what I would advise your breed to do in the absence of any concerted study or validated testing scheme. As an aside, I do not know of any screening test that has successfully identified physiological/measurable manifestations in advance of actual seizures. “
A treatment plan should be developed between an owner and their veterinarian. Obviously, if a dog has secondary seizures, correction of the underlying cause (if possible) can reduce the frequency of or even eliminate the seizures. Dogs with infrequent seizures may require no treatment and may just need to be monitored while others may require one or more anticonvulsant medications to control their seizures. Dogs with cluster seizures are challenging to control. Phenobarbital has traditionally been the drug of choice for treating seizures. There are, however, several new and promising drugs becoming more widely available for dogs.
WHAT WE DON’T KNOW
Unfortunately the one thing we do not know is the way idiopathic epilepsy is inherited. There are a number of possibilities as to its genetics, but until more specific research is done there is no way to say for sure as to which mechanism it follows. Judy Musladin and Ada Lueke wrote in the “New Beagle “that the inheritance can be followed as single recessive in the great majority of pedigrees we have studied”.
Research in other breeds has shown a potential genetic pattern although that pattern maybe polygenic in nature varying among breeds. A quote from the Canine Epilepsy Network “Epilepsy has been proven to be hereditary in several breeds and it is suspected in numerous other breeds. Right now, we don't know exactly how epilepsy is inherited in dogs. It may well be that there are different modes of inheritance and different genes involved in various breeds and families. Preliminary results from the Canine Epilepsy Project suggest that there are two or more genes involved in some of these families.”
A 2003 paper noted that in Vizslas “We conclude that IE in Vizslas appears to be primarily a partial onset seizure disorder that may be inherited as an autosomal recessive trait.” (http://www.ncbi.nlm.nih.gov/pubmed/12774973)
The best thought is that Primary Epilepsy is inherited in some manner and all efforts to breed away from affected individuals should be undertaken by intensive pedigree analysis.
The other thing we really don’t know is why different dogs have different types of or different frequencies to their seizures. We also don’t know why different dogs respond better to treatment than others. These questions may be answered one day if the genetics of this issue are ever determined.
FOR THE FUTURE
Breeding decisions in regards to epilepsy are difficult. The muddy, genetic waters makes it very
difficult to make blanket statements regarding breeding affected dogs. Every breeder makes their own decision on
which dogs to pair together based on many different factors influenced by their
priorities in their breeding program.
Breeders must balance breed type and health and what one can live with
may be a serious problem for another.
Particularly problematic is the dog that develops seizures later in
life, after they have made their contribution to the genetics of the breed. Opinions run high when serious health issues
arise and it is difficult to keep from throwing the baby out with the bathwater. Breeders need to remain open and honest about
health issues in their lines so that everyone can make an educated decision
that best fits their breeding program.
Breeders can make a positive impact on research of major health
concerns by donating DNA blood samples to the CHIC/OFA DNA Repository (http://www.caninehealthinfo.org/dnabank.html). In addition, donate as many samples directly
to researchers interested in epilepsy and the genetics of the disease. As of October 31, 2013 only 11 samples of
affected beagles or beagles with affected relatives have been received by the
Canine Epilepsy Research according to the stats provided by Dr. Ned Patterson
and Dr. Gary Johnson. (http://www.canine-epilepsy.net/index.html) Samples from affected dogs and their relatives
are critical, as are samples from normal dogs with no history of seizures in
their pedigree. Further research along
with samples and funding may lead us to a cause of seizures and perhaps,
ultimately, to a genetic test that can help breeders make educated breeding
decisions to eliminate this issue from our wonderful breed. If you have an affected beagle or a relative
of an affected beagle please submit pedigrees and DNA samples to this worthy
Ideally as a reputable breeders : If your bitch produces an epileptic puppy inform all owners of siblings, and the stud owner. If your stud produces an epileptic puppy, inform all that have bred to him in past and inform those breeding to him in the future. Please submit a pedigree for the record to the Chairperson of the NBC Health and Genetics committee. All information is held in confidence unless you give written permission for it to be open to public. As guardian of our breed, we need to come forward and take this subject out of the closet. Be honest-share knowledge and let’s take the next step to improve our breed.
For more information and review of article written by Ada Lueke for beagle breeders please visit.. Additional Information on Epilepsy.