My sisters dog seemed very healthy but from the age of about 5 onwards would suffer periodic virtual paralysis of her back legs. This would only last around a day or so. She didn't appear to be in any pain and I didn't over walk her though she loved running for the ball. The last day I took her out she seemed tired and didn't run very much so I took her back early. That evening she just dropped dead with no warning. We don't know what caused it as the vet said post mortems can cost a lot and even then we might still not know. Now my question is could the back leg paralysis have been the cause or a symptom of other health conditions such as a heart attack, a stroke, or a brain haemorage please. She was 7 and a half when she died and didn't have any other health conditions. This has been haunting me for ages now so I hope someone can help me please.