This means that all dogs, regardless of breed or size, can interbreed with any other breed and produce fertile and viable offspring. A species is defined as a group of plants or animals that is similar in appearance and behavior, and capable of interbreeding and producing viable and fertile offspring. All of them belong to the same species: Canis familiaris domesticus. There are almost 800 known dog breeds today and hundreds of millions of dogs in the world. As most people know, designer dog breeds, such as the doodles, are not pure breeds, but they are instead the offspring of two or more different breeds of dog. This is referred to as “breeding true,” or a “true-breeding” animal. These animals produce offspring that appear similar to the parent animals. In animal breeding, a pure breed includes animals that are all similar in appearance, behavior, function, origin, and genetics. In dog breeding, these “F” designations refer to the specific generation of cross-bred offspring that an individual dog or litter belongs to.
In the world of designer dog breeding, especially in those doodle breeds where it’s all about the low-shedding coat, you will often see the F1, F2, or F3. What exactly do these terms mean, and what do they have to do with goldendoodles, Labradoodles, and cockadoodles? (Okay, that last one is not a designer breed, but cockapoo people should really consider switching to this one.) Anyone remotely interested in a doodle breed has almost certainly seen the mysterious F1, F2, F3, and multi-generational designations associated with some dogs or litters.