Background
Ancient doggy love
Archaeologist and vet Luc Janssens studied the teeth of a prehistoric puppy and discovered the “very first evidence of an emotional bond between humans and canines.”
Wednesday 21 February 2018
It may not look like much, but these teeth are the first evidence of humans caring for dogs.

Hunters and gatherers living fourteen thousand years ago would primarily have seen dogs as useful creatures – at least, that’s what most archaeologists think: dogs would have guarded the camp, pulled sleighs and helped retrieve animals shot down by the hunters. But there was no evidence that people had the same emotional bond with their pets that we see nowadays.

Archaeologist and vet Luc Janssens discovered that a prehistoric pup that had been seriously ill several times was nursed by its owners. He examined the four-thousand-year-old teeth of a 24-week old puppy and realised that it had recovered from serious ill health three times, including a bout of canine distemper. It would never have survived without intensive nursing, says Janssens. “It’s the very first evidence of an emotional bond between humans and canines.”

His conclusion is that people must have tended the little creature. “So, we’re positing the theory that they helped it for emotional reasons. The puppy could not have had any use: it was young and had not been trained for anything. If it was ill, they could have just let it die. There were plenty of other puppies around.”

The bones were dug up over a century ago and have been in a museum for years: the pup’s remains were discovered by stonemasons in Bonn-Oberkassel back in 1914. The grave also contained the skeletons of a man of over forty and a woman of over twenty-five and several “works of art”, including an engraved bone.

Janssens, who read archaeology in Ghent after a career as a veterinary surgeon, came to Leiden to do research on the domestication of wolves. He had his doubts about the explanation for the teeth missing from the canine’s mouth, so he asked permission for another examination.

“Past studies reported that the dog’s teeth were missing because people had knocked them out with a rock to prevent serious injury if the dog bit anyone, but I found that hard to believe. I did a micro-CT scan and discovered that the teeth were missing for genetic reasons. There were no fractures to indicate they had been knocked out by rocks.”

He found something else, too: “I noticed enamel defects in contiguous teeth, a feature of dogs with morbillivirus, which causes canine distemper, a.k.a. hardpad disease. With the help of those teeth, we can see when the illness occurred, accurately to the week. Normally, only adult canines’ teeth are affected. When those teeth come through and replace the milk teeth, the virus prevents the production of enamel for a week.”

Accordingly, Janssens could tell that the dog had caught the virus when it was 19 weeks old. “We saw that it had been just as ill another two times: at 22 weeks and at 24 weeks. The pup recovered from the first two bouts but the third one must have been fatal, or else it was killed to be buried alongside the humans.”

The chances of the pup surviving naturally are “very, very slim”, he reports. “Most die in the first week. That’s when the dog is very ill and suffers from diarrhoea, vomiting and dehydration. In the second week, the virus attacks the respiratory system and they get bronchitis, a fever and still refuse to eat. The remainder usually dies at that point. Any exceptional dog that survives the illness often suffers from neurological disorders like epilepsy.”

In addition, the pup was not very strong to start with, according to Janssens, who could tell by the teeth that its immune system was not functioning properly. “The gum was inflamed so the underlying bone had rotted away. It’s a symptom of periodontitis, a kind of inflammation. Old dogs often have it, but this dog wasn’t even six months old and had a serious case.”

And there’s more: one of the teeth proved not to be the puppy’s. “That was another major discovery. I’m really proud of that. We’ve proved that one tooth came from an older, smaller, three-year-old dog. Only eight dogs of that age have been found, after a century of digs. It was added to the grave. Genetic examination is still to follow and will take a couple of years, but it might well be the puppy’s mummy or daddy.”

By Anoushka Kloosterman