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2021 World Record for Highest Amount of Kittens Born in a Litter

Kristin Hitchcock

On average, cats have about four kittens per litter. There are many factors going into this, including the size, breed, and health of the mother cat.

For instance, healthier cats tend to have more kittens – likely because more fertilized eggs were able to develop completely.

However, the world’s largest litter was recorded back in 1970, when a Burmese/Siamese mix had a litter of 19 kittens. Four of the kittens were stillborn, but they were still added to the total. This queen (a name for an unspayed female of breeding age) still holds the world record for the largest litter of kittens.

All of the surviving kittens were male except one, strangely enough.

Most cats will not have litters this big, though – not even close. There are many factors that affect how many kittens your average house cat has in a litter. But even if everything works out perfectly, most cats will never have more than 12 kittens in a litter.

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Factors Affect Cat Litter Sizes

two kittens cats litter box
Image credit: galsand, Shutterstock

Many factors that affect litter sizes are out of our hands. We can’t change our cat’s genetics, for instance. However, there are some factors that we can control.

  • Genetics – There is likely a genetic component to litter sizes. Cats tend to have similar litter sizes as their mother – given that there aren’t any other major factors involved. However, the science is a bit unclear on how large this genetic factor is. There have not been any controlled scientific studies on the matter, making it difficult to make any sure conclusions. Certain breeds do seem to have rather small or rather large litters. Therefore, there is some effect on genetics and litter size. If your cat is pedigreed, you may be able to determine their litter size with some accuracy, as you’ll have access to this genetic factor. With that said, some argue that litter size isn’t necessarily related to genetics directly – but size.
  • Size – Bigger cats usually have larger litters. This isn’t odd by any means. Larger dogs tend to have larger litters as well. Larger animals having larger litters seem to be an overarching theme for most mammal species. Generally speaking, size is related closely to genetics. Many argue that genetics don’t actually play a role in litter size, but a cat’s size (which is tied to genetics) does. Cat breeds that are bigger often have larger litter sizes than cats that are smaller. For instance, Burmese and Maine Coon cats are both recorded as having slightly larger litters (4.3 kittens per litter). Longhair and Exotic Shorthair cats only have 2.7 kittens per litter on average.
  • Diseases – Certain illnesses can affect a cat’s litter size. Theoretically speaking, the same number of eggs would be released and fertilized even if the cat was sick. However, fewer fetuses would develop correctly and make it to the actual birth. If the fetuses stopped developing early in the cat’s pregnancy, her body would likely reabsorb them. In these cases, most owners don’t even know that it has occurred. Some kittens can continue to develop while other kittens are absorbed. It is not an all-or-nothing process. It is nearly impossible to know how many kittens your cat actually started with since fetuses can be absorbed before they are even large enough to show up on an ultrasound. Alternatively, kittens lost later in pregnancy are often miscarried or stillborn. Feline infectious peritonitis, feline panleukopenia virus, and feline distemper all affect unborn kitten’s wellbeing. These latter two diseases do the most damage and can result in abortions and miscarriages. If the queen is infected late in pregnancy, the kittens’ brain development can be affected.
  • Nutrition – Nutrition is also exceedingly important. Breeding females should be eating a nutritious kitten, or all life stages food. Just like any animal, if the queen isn’t healthy, her kittens likely aren’t going to be healthy either. A cat that is malnourished may be unable to carry all of her kittens to term, which will result in smaller litter sizes. Many of the kittens may be unable to survive long after birth as well, especially if the mother’s milk is affected.
  • Age – There are some that claim age is related to litter size, though we were unable to find any scientific evidence to back this up. The general claim is that younger and older cats will have smaller litters. Middle-aged cats will often have the largest number of kittens. However, this factor seems to have a lesser effect than the others. A middle-aged, sick queen is not going to have a very big litter, for instance.

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Does Litter Size Matter?

Cat litter box_Lilia Solonari_Shutterstock
Image Credit: Lilia Solonari, Shutterstock

In many cases, cat owners often want their cats to have more kittens. After all, who doesn’t want more balls of fluff running around?

However, litter size is important in other ways too.

For instance, studies have found that certain white blood cell counts are raised in kittens from small litters. Typically, white blood cell counts will be higher when your body is fighting an infection. Based on this knowledge, it is hinted that kittens from smaller litters are more likely to get sick.

The research on this is in its very early stages, though. The study was also conducted on feral-type kittens living in outdoor conditions. Therefore, they are likely to be exposed to more illnesses than your average domestic kittens.

Furthermore, the increase in illness could be why there were fewer kittens in that litter, to begin with.

There is a strong correlation between litter size and temperament, though. Kittens need littermates during the first few months of their life to develop properly. In single-kitten litters, these littermates are obviously not available.

Research found that mothers of single-kitten litters often play more with the kitten. Still, the kitten receives less social interaction overall than kittens with littermates.

Due to this lack of social behavior, the kittens have increased levels of aggression when they grow older.

Generally speaking, the research appears to suggest that more kittens are often better. This fact is true whether you’re looking at the health of the kittens or their later temperament.

However, huge numbers of kittens can be harder for the mother to take care of, as you might imagine. Cats with extremely large litters often need a little help from their owners.

kitten in a litter box
Image Credit: Africa Studio, Shutterstock

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Final Thoughts

The largest litter size ever recorded was a litter of 19 kittens. A Burmese/Siamese mix gave birth to this litter all the way back in 1970, and no cat has had more kittens since then. There are many reports of 15-kitten litters, but none that reach close to 19.

Because this queen was a Burmese, her size likely played a role in this huge litter. However, most Burmese, Maine coons, and similarly sized cats don’t have anywhere near 19 kittens. In fact, the average is closer to four.

There are many factors that affect how many kittens are in a litter. Size and genetics likely play a role. The queen’s overall health is also important. Proper nutrition helps ensure that all the kittens get what they need to thrive. Illnesses can have a negative impact on litter size – some can even affect the development of the kittens.

In the end, moderately sized litters are often best for cats.


Featured Image Credit: Mr.Piya Meena, Shutterstock

Kristin Hitchcock

Kristin is passionate about helping pet parents create a fulfilling life with their pets by informing them on the latest scientific research and helping them choose the best products for their pets. She currently resides in Tennessee with four dogs, three cats, two fish, and a lizard, though she has dreams of owning chickens one-day!