Dogs find human yawns contagious, suggesting they have a rudimentary capacity for empathy, British scientists said on Wednesday.

Although yawning is widespread in many animals, contagious yawning — a yawn triggered by seeing others yawning — has previously only been shown to occur in humans and chimpanzees.

It turns out, however, that man's best friend is highly sensitive to catching human yawns, with 72 percent of 29 dogs tested yawning after observing a person doing so.

"Dogs have a very special capacity to read human communication. They respond when we point and when we signal," Dr Senju told BBC News.

The researchers explained that along with floppy ears and big soppy-eyes, humans have selected dogs to be obedient and docile. The results from this study suggest the capacity for empathy towards humans is another trait selected in dogs during domestication.

Dr Senju thinks that these traits would have been useful to humans when they began to live side-by-side with canines approximately 15,000 years ago.

Researchers at the University of Minnesota's Stroke Research Center looked at 4,435 people, aged 30 to 75 years, who were participating in ongoing national government health research from the National Health and Nutrition Examination Study.

They found that over a 20-year period, those who had never owned a cat had a 40 percent greater risk of death due to heart attack and a 30 percent higher risk of death due to any sort of cardiovascular disease than previous or current cat owners. Researchers found no such protective effects for dog owners.

"Maybe cat owners tend not to have high-stress personalities, or they are just the type of people that are not highly affected by anxiety or high-stress situations," Qureshi said.

"I have heard an owner with a chronic, debilitating illness say that her cat gives her a reason to get up each day," said Marla McGeorge, veterinarian at The Cat Doctor in Portland, Ore.

Here's what the researchers say they did: They took skin cells from Turkish Angora female cats and used a virus to insert the genetic instructions for making red fluorescent protein. Then they put the gene-altered nuclei into eggs for cloning. The cloned embryos were implanted back into the donor cats, which effectively became the surrogate mothers for their own clones.

Four kittens were born by Caesarian section, but one of them died during the procedure, according to the Korea Times. The fact that the kittens' skin cells glowed under ultraviolet light served as evidence that they were really gene-altered clones.

Assuming that the results are confirmed, Kong's cats would join mice and pigs in the glow-in-the-dark clone menagerie. The implication is that if you can pass along the easy-to-recognize coding for fluorescent markers through cloning, you could eventually pass along more complex genetic coding.

Theoretically, you could add in the coding for an endangered species, producing cloned hybrids to boost the gene pool for Sumatran tigers, Iberian lynxes and the like. You might even stick in the coding to give other creatures human diseases, so that they can be studied without raising the level of ethical concern that comes with human experimentation. (I realize that there's a different set of ethical concerns about such trangenic experiments, however.)