GSDIIIa DNA Testing Guide for Curly Coated Retrievers

The Curly Coated Retriever is one of the UK's oldest retrieving breeds, known for its intelligence, energy, and friendly nature. They make excellent companions for active families and thrive with plenty of exercise and engaging training. However, like many pedigree breeds, they face risks of hereditary conditions such as glycogen storage disease (GSDIIIa), a serious inherited disorder affecting glucose metabolism.

1. Understanding Glycogen Storage Disease (GSDIIIa) in Curly Coated Retrievers

Glycogen Storage Disease IIIa (GSDIIIa) is a genetic condition unique to Curly Coated Retrievers caused by a mutation that leads to a deficiency of the enzyme glucose-6-phosphate in the body. This enzyme is critical for producing glucose used as an energy source. Deficiency results in glycogen accumulation primarily in the liver and muscles, causing progressive damage.

Typical symptoms include chronically low blood sugar (hypoglycaemia), enlarged liver (hepatomegaly), muscle weakness, seizures, and failure to thrive. Sadly, puppies affected by GSDIIIa often face premature death without appropriate management. The disease is usually fatal in young dogs.

2. How GSDIIIa is Inherited

This disorder follows an autosomal recessive inheritance pattern. A dog must inherit two copies of the defective gene—one from each parent—to develop the disease. If only one mutated gene is inherited, the dog is a carrier but shows no symptoms.

This means responsible breeding requires knowing the genetic status of parent dogs to avoid passing the condition to puppies. Understanding test results helps breeders make informed decisions to prevent affected litters.

3. The DNA Testing Process for GSDIIIa

DNA testing is the definitive way to determine a Curly Coated Retriever's genetic status for GSDIIIa. Testing typically involves your vet collecting a simple buccal (cheek) swab or blood sample, which is then sent to an authorised UK laboratory for analysis.

The test results classify dogs as:

• Clear (normal): no copies of the mutated gene, and do not carry the disease.
• Carrier: one copy of the mutated gene, no clinical signs but can pass the gene on.
• Affected: two copies of the mutation and likely to develop the disease.

Testing both breeding partners is crucial to assess the risk to their offspring.

4. Breeding Recommendations to Prevent GSDIIIa

Breeders should aim to use dogs that test clear for GSDIIIa wherever possible and avoid breeding two carriers together, which risks producing affected puppies.

Responsible breeding strategies include:

• Pairing clear dogs with any partner, ensuring healthy litters.
• Breeding carriers only with clear dogs and testing all resulting puppies to identify carriers and affected pups.
• Excluding affected dogs from breeding programmes to stop spreading the disease.

Transparency in sharing test results supports the breed's health and helps prospective owners choose healthy puppies.

5. Recognising Symptoms of GSDIIIa in Dogs

Early detection may be challenging as signs can be subtle but watch for:

• Lethargy and weakness especially after exercise or fasting
• Episodes of low blood sugar including tremors or seizures
• Enlarged liver diagnosed by your vet through imaging
• Muscle wasting and difficulty with movement

If you notice any of these signs, consult your vet promptly for testing and diagnosis. Early diagnosis can help manage symptoms and improve quality of life, though the prognosis remains guarded.

6. Conclusion and Next Steps for Owners and Breeders

Glycogen storage disease (GSDIIIa) is a rare but serious genetic condition in Curly Coated Retrievers that requires awareness and responsible actions from breeders and owners alike. DNA testing offers a practical tool to safeguard the breed's health and avoid suffering in puppies.

• Discuss testing your dog for GSDIIIa with your vet if you are considering breeding or have concerns about symptoms.
• Ensure both prospective parents are tested before mating to understand risks to puppies.
• Adopt breeding practices that prioritise health by avoiding carrier-to-carrier matings and favouring clear dogs.

By following these guidelines, we can help ensure future generations of Curly Coated Retrievers remain healthy, happy members of families for years to come.