Yes, a litter of kittens may have multiple fathers. This means that each kitten will be mothered by the same cat, but two or more of the kittens may have different fathers. Sometimes this is apparent in a litter because the kittens look vastly different. When a litter has more than one father, it is called superfecundation.
The litter that my cats came from was made up of 5 kittens. Their appearance varied greatly. The litter included one tortoiseshell cat, one long-hair grey cat, one long-hair orange and white cat, one short-hair black and white cat, and one short-hair orange and white cat. We adopted the long-hair orange and white and the short-hair black and white. The differences in these siblings are very significant physically, although they also have many similarities. I suspect that our pair had different fathers, but the only way to confirm superfecundation is through fraternal DNA testing.
How Does It Happen?
Female cats go through heat cycles when they are ready to conceive. They only ovulate when a male cat mates with them. Ovulation may take some time to occur after a female first mates, leaving time for mating with other males.
Superfecundation doesn’t happen all the time because a dominant male cat will often mate with the female in heat and then prevent other male cats from mating with her. When cats are bred by owners they owners make sure that a female only mates with one male to ensure he is the father.
Is It Safe?
There is no health risk to the mother or kittens due to superfecundation (multiple fathers in a litter.) It is natural in mammals that carry litters of babies, including dogs!