LAFORA
EPILEPSY IN BEAGLES
Lafora
disease
is a recessive genetic trait inherited late onset progressive
myoclonic
epilepsy. Myoclonus (jerking) is a feature of the disease which
characteristically can be induced by flashing lights), sudden sounds
and
movement especially that close to the dog's head. Generally, the
clinical signs
appear at 5-6 years of age or later. It progresses, gradually
causing
neurological changes over many years. They include mainly
myoclonus/jerking
(sudden involuntary muscle jerking or twitching typical for epilepsy)
and the
frequency of seizures increases over time and the uncontrolled jerking
and
twitching is followed by other neurological symptoms such as ataxia,
twinkling,
blindness or dementia. During seizures, the convulsions are commonly
accompanied by muscle rigidity, vocal utterance, salivation, urination
or loss
of consciousness. The epileptic seizures can arise in spontaneous
unpredictable
fashion or can be induced by light flashes, sudden sounds or movements,
particularly
close to the dog´s head.
It has been discovered in pedigree miniature wire-haired
dachshunds. Other breeds
suffering from this disease belong can be Basset Hounds, Miniature and
Standard
Poodles, Pointers, Welsh Corgis or Beagles. This form of epilepsy is
incurable
and fatal. The therapy is currently limited to treatment of seizures;
suitable
diet and medication help to keep the seizures under control.
A
NHLRC1-gene mutation is responsible for Lafora´s epilepsy in
beagles und
miniature wire-haired dachshunds. The gene dysfunction leads to
aggregation and
accumulation of polysaccharides and formation of glycogen particles
(named
Lafora bodies). Simply, the NHLRC1-gene takes part in
protection of
tissue against carbohydrate accumulation. The protective power is lost
due to
this mutation. The Lafora bodies are gradually growing in the central
nervous
system where they have neurotoxic effect. Besides the brain tissue the
Lafora
bodies are found in muscles, skin, liver and heart. Lafora disease is
actually
a glycogen metabolism disorder that demonstrates itself as progressive
myoclonus epilepsy.
Mutation that causes Lafroa epilepsy is inherited as an autosomal recessive trait. That means the disease affects dogs with P/P (positive / positive) genotype only. The dogs with P/N (positive /negative) genotype are clinically without any symptom. They are genetically considered carriers of the disease (heterozygotes). In offspring of two heterozygous animals following genotype distribution can be expected: 25 % N/N (healthy non-carriers), 25 % P/P (affected), and 50 % N/P (healthy carriers).
Genetic testing that enables to determine the dog´s genotype is
generally
recommended. It can help the breeder to select potential breeding pair
to
ensure that the risk of producing affected puppies is very low and
this disease
will be gradually eliminated from the breed.
Here is a link to one lab that does test for Lafora. Genomia
TREATMENT
OPTIONS
Research
has shown that benefits may be obtained by a dietary change for you
dog. These
changes may include a change to a food with a low glycemic index.
Starchy
and sugary treats are suspected of aggravating the condition Various
medications or combination of medications use in treating the epilepsy
are phenobarbital, potassium bromide or, levetiracetam
(Keppra). Since sunlight is a known trigger for the seizures and
some dog
owners use doggy sunglasses (Doggles) when they have their family pet
outdoors
for walking and other exercise activities. Also, you may
need to be
more aware of the flashing lights in home environment that might
trigger
seizures. One example would be lights which emanate from the
television
during some programs are video games.
ADDITIONAL
RESOURCES
You
Tube videos of affected
beagles:
https://www.youtube.com/watch?v=dgKTKV2CdGo
https://www.youtube.com/watch?v=JzysRR3hP-M&t=27s
https://www.youtube.com/watch?v=mg_m8WmWWvc&t=28s
https://www.youtube.com/watch?v=t7LYu9uX1yY
Informational
Websites:
http://www.veterinary-neurologist.co.uk/Laforas_disease/
https://wagwalking.com/condition/lafora-disease
http://www.canineepilepsy.co.uk/lafora-disease-research.html