Common Symptoms
Neonatal Encephalopathy with Seizures is an inherited neurologic disease known to dogs. Affected puppies are smaller than littermates at birth, have difficulty nursing after a few days of life, and often die by 1 week of age. By 3 weeks of age, surviving puppies present with neurologic symptoms including muscle weakness, tremors, inability to walk, wide-based stance and frequent falling. The disease quickly progresses to severe seizures that become non-responsive to treatment. Affected dogs typically die or are euthanized by 7 weeks of age.
Breed-Specific Information for the Toy Poodle
Toy Poodle is included as a breed susceptible to neonatal encephalopathy with seizures because of its close relatedness to the Standard Poodle breed, which is known to develop this disease due to Mutation of the ATF2 gene. The frequency of the causal mutation in the general Toy Poodle population is unknown.
Testing Tips
Genetic testing of the ATF2 gene in Toy Poodles will reliably determine whether a dog is a genetic Carrier of neonatal encephalopathy with seizures. Neonatal Encephalopathy with Seizures is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of inheriting one copy and being a carrier of the ATF2 gene mutation. Reliable genetic testing is important for determining breeding practices. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Toy Poodles that are not carriers of the mutation have no increased risk of having affected pups.
There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.
References
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Chen X, Johnson GS, Schnabel RD, Taylor JF, Johnson GC, Parker HG, Patterson EE, Katz ML, Awano T, Khan S, O'Brien DP. A neonatal encephalopathy with seizures in standard poodle dogs with a missense mutation in the canine ortholog of ATF2. Neurogenetics. 2008 Feb; 9(1):41-9.
[PubMed: 18074159]
