Yes. My cavalier died of heart attack, it was so quick and so distressing.

Yep, sadly they do.

yes but none of mine did yet.

1) "The HFA alleges that workers are required to kill up to 1,100 hogs an hour, and end up taking their frustration out on the animals. Eisnitz interviewed one worker, who had worked in ten slaughterhouses, about pig production. He told her: “Hogs get stressed out pretty easy. If you prod them too much, they have heart attacks. If you get a hog in the chute that's had the shit prodded out of him and has a heart attack or refuses to move, you take a meat hook and hook it into his bunghole (anus). You try to do this by clipping the hipbone. Then you drag him backwards. You're dragging these hogs alive, and a lot of times the meat hook rips out of the bunghole. I've seen hams — thighs — completely ripped open. I've also seen intestines come out. If the hog collapses near the front of the chute, you shove the meat hook into his cheek and drag him forward.”" Source and further information: http://en.wikipedia.org/wiki/Slaughterhouse 2) "Results of a study show that stem cell therapy can be used effectively to treat heart attacks in pigs. In just two months, stem cells harvested from another pig’s bone marrow and injected into the animal’s damaged heart restored heart function and repaired damaged heart muscle by 50 percent to 75 percent." Source and further information: http://stemcell.taragana.net/archive/stem-cell-therapy-successfully-treats-heart-attack-in-animals-patients-enrolled-for-phase-1-clinical-trial/ 3) "Adult clones in sudden death shock Pig fatalities highlight cloning dangers. New fears have been raised about the health of cloned animals after three cloned adult pigs dropped dead from heart attacks. The pigs were created using a variation on the technique that made Dolly the sheep. A Taiwan-based team rammed a whole adult cell into a fertilized egg that was emptied of its own genetic material1. Of four piglets born, one died within days. The remaining three have now collapsed and expired of heart failure at less than six months of age, team leader Jerry Yang of the University of Connecticut in Storrs revealed this week. "It was totally shocking," says Yang. He has dubbed the fatalities 'adult clone sudden death syndrome'." Source and further information: http://www.gene.ch/genet/2003/Sep/msg00015.html 4) "A chimpanzee who was tranquilized after arriving at a Texas animal refuge died of a heart attack, according to a necropsy report, and not from suffocation as a refuge veterinarian said." "The report said the heart attack was associated with pre-existing heart disease, pulmonary congestion and tissue swelling associated with handling. The necropsy did not address tranquilizers in Kermit's body." Source and further information: http://www.columbusdispatch.com/live/contentbe/dispatch/2006/03/23/20060323-B1-04.html 5) "It is usually possible to help dogs with mitral valve failure adjust to the problem and most will live a long time with the aid of medications and good overall care. The ventricle enlarges but this does not pose a threat of rupture. Heart attack, as it occurs in humans, is a very rare event in dogs. However, there will eventually be heart failure that will no longer respond to medications and nursing care. It may be years before that happens, though." Source and further information: http://www.vetinfo.com/dogheart.html