Juvenile Epilepsy

The condition now known as juvenile epilepsy was first researched and identified as a probable inherited condition by the pioneer breeders in the UK. Puppies were observed with seizures and ataxia usually between five and 13 weeks of age. The condition was described initially by the Lagotto Romagnolo Club of Great Britain (LRCGB) as cerebellar anomaly. 

Inherited benign juvenile epilepsy resembles idiopathic childhood epilepsies with benign outcomes in human. Clinical and diagnostic evaluations of affected dogs including electromyography, electroencephalography, and other testing indicated that seizures in puppies begin at 5 to 9 weeks of age and usually resolve by 8 to 13 weeks. There are some adult-onset cases in the breed too. Dogs with the most severe seizures also have other neurologic signs such as generalized ataxia and hypermetria. Routine laboratory screenings of blood, urine, and cerebrospinal fluid did not reveal abnormalities. Electromyography, brainstem auditory-evoked potentials, and magnetic resonance imaging (MRI) remain normal in analysed dogs. However, most affected puppies and adult cases revealed epileptiform activity in the electroencephalogram (EEG). Histopathologic examination shows cerebellar lesions in two studied Lagottos. Pedigree analysis suggests an autosomal recessive mode of inheritance.

First clinical investigations were carried out in the late 1990s at Stone Lion clinic, London. As a result of the efforts by the LRCGB to publicise the existence of this hitherto unreported condition, investigations were subsequently performed in several countries, notably Finland, and a DNA-based test for carriage of the condition (renamed juvenile epilepsy) has been available since May 2008.

The study of the genetics of the juvenile epilepsy in Lagotto led to the causative gene being identified. If a dog carries one copy of the mutations it can transfer the gene defect to approximately 50% of its offspring. If the dog has two copies of the mutation it transfers the defect to all of its offspring. It is recommended that dogs that are homozygous for the Lagotto epilepsy mutation are withdrawn from breeding programs. Normal and carrier dogs can be used but it is advised to choose mutation-free partners for carriers.

The development of the test made it appear that the epilepsy may be (at least, in some cases) distinct from another inherited neurological problem affecting Lagotto of similar age but with slightly different clinical signs. In these cases, weakness, tremors, and an inability to control limbs are prominent features. These neurological deficits are sometimes more severe and accompanied by foreshortened muzzles. However, it should be noted that the parents of the UK-bred puppies showing these more severe signs were the result of two clinically normal (as pups and adults) being mated, both of which subsequently tested affected (homozygote) for the juvenile epilepsy mutation. Both syndromes are accompanied by changes in a part of the brain known as the cerebellum. This second disease is still known as cerebellar anomaly, cerebellar ataxia or cerebellar abiotrophy.

In June 2008 the LRCGB initiated a club scheme to eventually eradicate the mutant gene. Carrier dogs may only be mated to normal dogs, either tested or hereditary clear.

If you wish to have your dog tested for JE please contact the club.

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