The domestic cat, known scientifically as Felis catus, is a member of the Felidae family. The widespread curiosity about which animals a cat can breed with is a question about the fundamental boundaries of biology. Most cross-species pairings are impossible due to biological barriers that prevent the formation of viable, fertile offspring. These barriers exist to maintain the distinct identity of each species, and only a select few species share enough genetic compatibility to overcome them.
Genetic Requirements for Successful Breeding
The primary constraint on interspecies breeding is reproductive isolation, which prevents different species from successfully producing fertile progeny. This isolation occurs because the sexual reproductive cells, the gametes, from two different species are typically incompatible. When a sperm and egg from different species meet, they must successfully fuse to form a zygote.
The most significant physical barrier to this process is the mismatch in chromosome number and structure. Domestic cats possess 38 chromosomes, arranged in 19 pairs. For a successful pairing to occur, the chromosomes contributed by each parent must be able to pair up correctly during cell division, or meiosis, in the offspring.
If the two parent species have different chromosome counts, or if the structure of their chromosomes is too dissimilar, the resulting hybrid embryo will often fail to develop and be spontaneously aborted. Even if the hybrid survives to birth, the mismatched chromosomes cannot align properly during the formation of its own gametes. For instance, a hybrid cat with 37 chromosomes cannot divide its chromosomes evenly to create viable sperm or eggs.
This chromosomal incompatibility is the mechanism behind hybrid sterility, which functions as a natural barrier to gene flow between species. The inability to produce functional gametes means the hybrid cannot pass on its genetic material, effectively terminating the genetic line. This foundation is why breeding across genera or even families, such as between a cat and a dog, is biologically impossible.
Feline Hybrids and Compatible Wild Species
The only animals a domestic cat can successfully breed with are a select few species within the Felidae family. These are small wild cats that are closely related enough to share significant genetic and chromosomal compatibility. These successful pairings are almost always the result of human intervention and selective breeding. The key to these pairings is their close genetic relationship, meaning both species often share the same chromosome number of 38.
One well-known example is the Bengal cat, a hybrid of the domestic cat and the Asian Leopard Cat (Prionailurus bengalensis). Another popular hybrid is the Savannah cat, a cross between a domestic cat and the African Serval (Leptailurus serval). Other successful crosses have involved the Jungle Cat (Felis chaus) to create the Chausie, and the European Wildcat (Felis silvestris) and African Wildcat (Felis lybica), both of which are close relatives to the domestic cat.
The offspring of the initial cross between a domestic cat and a wild cat are known as the first filial generation, or F1. Haldane’s Rule often applies to these hybrids, stating that the heterogametic sex—the male, in the case of mammals—is the one that is sterile. F1 male hybrids, such as those from Bengal and Savannah lines, are almost always infertile, though the F1 females are typically fertile.
To perpetuate the breed and produce fertile males, breeders must repeatedly “backcross” the fertile F1 females to domestic cat males. This process dilutes the wild cat’s genetic contribution with each subsequent generation (F2, F3, F4, and so on), eventually leading to fertile male offspring, usually starting with the F4 generation. This multi-generational process is necessary to overcome the subtle genetic incompatibilities that still exist.
Why Cats Cannot Breed With Other Mammals
The genetic principles that permit successful hybridization among closely related wild cats simultaneously explain why breeding with non-feline mammals is impossible. The reproductive barriers between cats and other mammals, such as dogs, rabbits, or squirrels, are too great to be overcome. These species belong to different taxonomic orders, meaning their last common ancestor lived tens of millions of years ago.
The most straightforward barrier is the disparity in chromosome numbers. A domestic cat has 38 chromosomes, while a dog (Canis familiaris) has 78 chromosomes. A rabbit (Oryctolagus cuniculus) has 44 chromosomes, and the common gray squirrel (Sciurus carolinensis) has 40. The difference in the number and structure of chromosomes prevents the formation of a viable zygote, as the genetic material cannot combine to create a functional set of genetic instructions.
Any reports or myths of hybrids between cats and other species, like a “cabbit” or a “dog-cat,” are scientifically unfounded. These reported animals are almost always cases of misidentification, genetic mutation, or developmental abnormalities within a single species. For example, a cat with a short or missing tail may be misidentified as a cat-rabbit hybrid, when it is simply a cat with a genetic mutation, such as that seen in the Manx breed.
The superficial similarities in appearance or behavior between a cat and another mammal are meaningless in the context of reproductive biology. The machinery of reproduction, from the molecular structure of the gametes to the precise choreography of the chromosomes during cell division, is species-specific. The sheer evolutionary distance between a cat and any non-feline mammal ensures that any attempt at cross-breeding will result in immediate embryonic failure.