“Left-over cells” in dogs — and humans — might lead to incurable diseases.

A study on dogs at the University of Missouri might show whether microchimerism in dogs leads to cancer, multiple sclerosis, autoimmune diseases, arthritis and more. Whether the same is true for humans remains to be seen.

Microchimerism is when cells from a newborn remain in a mother’s body, and although foreign, continue to live and thrive. Doctor Sinthil Kumar at the University of Missouri School of Veterinary Medicine says studies on dogs, which live comparatively shorter lives than humans, could provide answers more quickly.

“We take blood from female dogs who had a litter,” Kumar says. “We follow up on trial dogs, which makes it easy, because the owners keep very good records, and we follow up on how many litters the dogs have had, how long they live.”

He says the testing looks for male DNA in the female body, which happens after a female gives birth to a male.

“In order to link something, we need more studies,” he says. The cells are “found in brain, lungs, liver, heart … everywhere. We don’t know the biology of how it works in the long term. We are a long time from seeing if there’s a correlation.”

Females do not reject the cells, Kumar says, in fact, “they are well tolerated in the mother.”

“We are trying to see if the presence of this chromosome means anything or if it’s a marker; whether we can say this is definitely the problem,” Kumar says. “We are trying to pursue the studies … to get some information … at least in a couple of years. To see if these cells exist in female dogs. We will try then to extend the studies in humans to see if the cells are present.”

He says the goal is eventually to carry these studies over to humans, to see how microchimerism affects the human body, but that it takes nearly 70 years for certain diseases to show up in humans, compared to about 14 years in dogs. Kumar says dogs represent an excellent model of many ailments in people, so working with dogs allows studies that further clarify the role of microchimerism in human health and disease.

He says there is no obvious link from microchimerism to cancer at this point, whether that’s good or bad.

AUDIO: Jessica Machetta reports (1:21)