X-linked severe combined immunodeficiency (corgi type) is an inherited disease affecting Cardigan Welsh corgis. Affected dogs are unable to produce a protein important for proper immune function, predisposing them to severe recurrent or chronic bacterial, viral and fungal infections. Affected dogs often present with symptoms of disease around 6 to 8 weeks of age including failure to thrive, poor growth, weight loss, lethargy, diarrhea, vomiting and lack of palpable lymph nodes. Affected dogs may also present with active respiratory, skin, eye or ear infections. Affected dogs die within 4 months of age.