ELI5: Explain Like I'm 5

Canine transmissible venereal tumor

Okay kiddo, so you know how dogs can get sick sometimes, just like people? Well, there's a type of sickness that they can get that's called canine transmissible venereal tumor, or CTVT for short.

It's a type of cancer that affects dogs, which means that some of the cells in their body start growing really fast and in a way that's not normal. But what makes CTVT different from other types of cancer is that it can actually be passed from one dog to another through...well, let's just say through a part of their body that's used for making puppies.

That might sound a little strange, but basically what happens is that an infected dog will have some of the cancer cells in that area, and when they mate with another dog, they can pass those cells on to the other dog. Then, those cells can start growing inside the new dog too, and they might make the dog sick.

So, why does this happen? Well, sometimes when cells in a dog's body start growing abnormally, it can be because of changes in their genes, which are like the instructions that tell their body how to work. And with CTVT, scientists think that the cancer cells might have originally come from one dog whose genes had changed in a way that made the cells grow out of control. Then, every time the cancer cells were passed from one dog to another, they kept growing and copying themselves in the new dog's body.

Now, the good news is that CTVT can actually be treated pretty well, especially if it's caught early. Dogs can get chemotherapy, which is a special kind of medicine that can help stop the cancer cells from growing. And once the cancer is gone, the dog will usually be back to their happy, healthy self in no time!