Have you ever wondered what the letter & number abbreviations (such as F1B) mean when you have seen, for example, on an advert for a dog or puppy?
I will explain each meaning to you so when your are looking for your next dog/puppy, or are thinking of breeding and are not sure what category your puppies fall under, you will know exactly what is part of the dogs/puppy’s genetic background.
There is so much ‘designer’ dog breeding nowadays and you will often see these dogs listed as F1, F2, F3 etc. The F refers to the specific generation of the cross-bred dog/puppy belongs to.
When two different breeds are crossed it is called outcrossing. The generations of their offspring are known as the filial generations, which have two varieties of one gene, each inherited from their mother (dam) and father (sire).
Crossbred dogs and designer dogs are often referred to as F1, F2, or F3, or even F1b or F2b generations. It is the terminology that we can make a distinction between the different generations of hybrid dog breeds.
This naming standard applies for designer dog breeds, hybrids and mixes, but it is also commonly, and scientifically, applied to cats, cattle, plants, and most living organisms (even cells).
Below is an explanation of each of the generations:
P generation
This refers to 100% purebred dogs.
F1 generation
Two purebred dogs (two different breeds) are mated and the puppies of this mating will be 50% purebred – 50% purebred. Half of each puppy is the mother’s breed, and the other half is the father’s breed. For example, a Puggle is bred by one parent being a purebred Pug and one parent being a purebred Beagle. So in conclusion, F1 technically means 50/50.
F1B generation
Dogs classed as F1B are the result from the mating of an F1 parent and a P parent, so are classed as F1 backcrossed dogs. This is used to strengthen traits found in the P parent’s breed. F1B is 75% purebred – 25% purebred. For example, a breeder who breeds F1B Jug’s and wants stronger traits of Jack Russell Terrier would breed one parent who is purebred Jack Russell and one parent who is a F1 Jack Russell x Pug mix.
F2 generation
F2 generation is the mating of two F1 hybrids. So one parent is 50/50 and the other parent is 50/50, both mixes of the same breeds. For example, an F2 labradoodle’s mother is an F1 labradoodle and the father is also an F1 labradoodle.
F2B generation
These are second-generation backcrossed dogs. Each F2b dog is the offset of an F1 parent and an F1 backcrossed (F1b) parent. For example, an F2B Cavapom has one parent who is 50/50 Cavalier King Charles Spaniel x Pomeranian mix and the other parent is 75/25 Cavalier King Charles Spaniel x Pomeranian mix.
F3 generation
F3 generation puppies result from the mating of two F2 hybrid parents. So for example, the puppies grandparents on both the mother and fathers side are F1, the dogs parents are both F2, making the puppies F3.
Multi Generation
This is when an F3 or higher-generation hybrid dog is mated with an F3 or higher-generation hybrid dog. For example, a multi generation Lasalier might have one parent who is an F3 Lhasalier and one parent who is an F5 Lhasalier.
In the below example, the parents are:
Pedigree + F1 = F1B puppies
This puppy is F1B Lhasa Apso x Shih Tzu:
This is the puppy’s father who is is a pedigree Lhasa Apso.
This is the Puppies Mother who is F1 Lhasa Apso x Shih Tzu.
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