The relationship between people and dogs likely developed much earlier than originally thought. Researchers recently examined the contents of a grave discovered more than a century ago. They found that a dog in that 14,000-year-old grave had been sick for a long time and taken care of.

The grave was discovered by chance in 1914 by a group of workers not far from Bonn, Germany. It included the remains of a man, a woman and two dogs.

Researchers recently examined the dogs and found that the youngest was about 7 months old when it died. They were able to determine that it was suffering from the morbilli virus or canine distemper, which it likely contracted when it was about 3 or 4 months old. The scientists believe it's unlikely the puppy would've survived that long without help from its human companions.

"Without adequate care, a dog with a serious case of distemper will die in less than three weeks," said Leiden University Ph.D. candidate and veterinarian Luc Janssens, who led the research. Janssens points out that the puppy was critically ill, yet survived for another eight weeks, which would only be possible if it had been well taken care of.

"That would mean keeping it warm and clean and giving it food and water, even though, while it was sick, the dog would not have been of any practical use as a working animal. This, together with the fact that the dogs were buried with people who we may assume were their owners, suggests that there was a unique relationship of care between humans and dogs as long as 14,000 years ago."

Janssens and his team were able to make the distemper diagnosis by examining the remains of the dog's teeth.

The teeth of the younger dog from the grave, with traces of the morbilli virus (canine distemper). The teeth of the younger dog from the grave, with traces of canine distemper. (Photo: Pütz Martin, Jürgen Vogel, Ralf Schmitz /LVR-LandesMuseum Bonn)

The researchers also point out that because the puppy was too young to have had any practical use for hunting, the humans likely had a bond with the animal.

"We suggest that at least some Late Pleistocene humans regarded dogs not just materialistically, but may have developed emotional and caring bonds for their dogs, as reflected by the survival of this dog, quite possibly through human care," they said in the abstract, which was published in the Journal of Archaeological Science.

According to the researchers, this is the oldest known grave where humans and dogs were buried together. It's also among the earliest evidence of dog domestication.

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.