Genetic basis of DAMS in English Springer Spaniels - is caused by a recessive mutation in the EHBP1L1 gene. The gene EHBP1L1 plays a critical role in intracellular trafficking and cellular function. The mutation causes dysfunction in red blood cell development (dyserythropoiesis) and progressive muscle disease (myopathy).
Pathophysiology - The disease typically presents with early onset anemia, muscle atrophy notably affecting temporal and pelvic muscles, regurgitation due to megaesophagus, and cardiomyopathy in some cases. Blood tests show microcytosis, inappropriate metarubricytosis (presence of immature red blood cells in circulation), and erythrocyte abnormalities. Muscle biopsies reveal features consistent with centronuclear myopathy — centralized muscle nuclei, fibrosis, and fatty infiltration. Megaesophagus leads to difficulty swallowing and regurgitation, increasing risk for aspiration pneumonia
Complications - Progressive muscle wasting with significant mobility impairment. Severe anemia leading to poor oxygen transport and fatigue. Megaesophagus-related complications such as aspiration pneumonia. Cardiomyopathy causing heart failure in some dogs.
Clinical Presentation - Symptoms often appear shortly after birth or early in life, with affected dogs being less active, showing progressive weakness, difficulty eating, and muscle wasting. Severity varies, but the condition leads to significant quality-of-life impact and often euthanasia occurs between 1 and 7 years of age. Cardiomyopathy may be present but was not universally observed.
Inheritance - DAMS is inherited in an autosomal recessive pattern, meaning affected dogs have two copies of the mutant gene, while carriers (with one copy) are asymptomatic. Testing has confirmed the mutation segregates within families and the breed
Why This Matters to Breeders and Vets - Early diagnosis through genetic testing enables breeders to avoid at-risk matings and reduces the prevalence of the disease. Veterinary management can focus on supportive therapies and complication prevention. Identification of this mutation in English Springer Spaniels helps understand similar human congenital conditions.