Our precious pooches can carry one of many strangest diseases known to exist—a sexually transmitted type of cancer that’s jumped from host to host for thousands of years. Now, a large group of researchers says they’ve unpacked the evolutionary history of this disease, all the way back to the first dogs through which it arose. And it’s even weirder than anticipated.
Most cancers—the mutated, uncontrollable, and harmful development of a body’s cells—are unique. Sure, for those who and someone else both has a specific type of breast cancer, those cells will behave in similar methods. However, your cancer cells belong to you alone, and they’ll be noticeably different from the cancer cells of another individual. You also can’t actually infect someone together with your cancer, mostly as a result of our immune system can usually acknowledge and destroy foreign human cells.
That stated, there have been rare examples of cancer transmission in people. These have largely happened to folks with poor immune systems which obtained organ transplants from a donor with cancer, or from mother to child within the womb. However, they’re short-lived, remoted cases, with cancer never spreading additional to others.
However, some cancers in some animals have been able to take on an infectious life on their own, having “learned” the way to escape their original hosts and spread freely throughout the population as a bacteria or virus does. One of these immortal rogue agents is called the canine transmissible venereal tumor, or CTVT. And as the name indicates, it’s sexually transmitted.