Assertion: heart murmur's symptom | /r/CapableOf | become collapse of the hind legs
Facets:
Source sentences:
text: If the dog develops this “reverse PDA”, the heart murmur will disappear, and the symptoms will become severe and debilitating, including abnormal heartbeats, blueness or ‘cyanosis’ of the foot pads on the hind legs, collapse of the hind legs when the dog exercises, and weakness or lethargy.