How to Tell if Your Cat is a Runt?

How to Tell if Your Cat is a Runt

In some litters, there is one kitten that is weak and small. This little kitten is often considered the runt cat. Newborn kittens are fragile and even more so with runts. Because of its size and weakness, a runt might have a hard life initially.

What is a Runt?

A true runt is an animal born with unusually low birth weight. Almost every newborn kitten has a pretty normal weight, but a runt’s birth weight is significantly below the normal birth weight range. In most cases, the lack of growth in runts has to do with their placement in the uterus. Runts are usually situated farthest from the source of nourishment, resulting in a lower birth weight compared to other kittens.

Because of a runt’s smaller size, pet owners have to assist and monitor a runt after birth to ensure that it gets the food and nutrients it needs to grow and thrive. Its size also often finds it fighting with their siblings at feeding time, which sometimes necessitates bottle-feeding.

Even when runt cats grow up, they may be physically not as strong as other cats. However, this does not make them any less than the other cats. Runts with proper nourishment can grow happy and healthy.

How to identify a runt?

When you put all the kittens together, the runt can be identified by its size compared to its siblings. Aside from that, there are other indicators that tell if your cat is a runt.

Small Size

Runts have the lowest birth weight in the litter. They are usually malnourished and may have difficulty in opening their eyes. Because of their size, they do not have easy access to their mother cats for feeding and crucial body warmth.


Runts have difficulty moving compared to other kittens that can roam around. They often stay still in one corner. Since they are small and weak, they cannot always stand up for themselves. When they are not well attended, they will have a hard time surviving.

Disability or deformity

Some of the runts may also suffer from disability or deformity. They may have crooked legs, less number of paws, deformity in eyes or any other underdeveloped organ. They may not be able to run or walk properly and limp.

Inability to have food or suck milk

You can also identify a runt if your cat is facing difficulty while having food or sucking milk. A runt cat is often not strong enough to grasp and suckle the mother cat’s nipple. Their larger littermates also often shove them out of the path for food, leaving them hungry and dying.

How to care for runt cats?

Fading kitten is a syndrome which is a concern with any newborn, especially with runts. Weight gain must be monitored closely. It is important to monitor the feeding of the runt and help it onto a teat. If the queen is rejecting it, or it has a hard time sucking milk, you can provide kitten milk formula. 

Feed your kitten quality food at the recommended serving size. Do not assume it needs more to catch up with the bigger ones. Aside from feeding, the runt kitten will also need petting and cuddling, as well as assistance in toileting. The mother cat licks the bottoms of kittens to stimulate urination. If it is not performing that duty, you will have to fill in with a clean, moist rag.

If a runt is not gaining weight, a veterinary check is necessary. In addition to low birth weight, runts also may suffer with other developmental issues such as weak bones, underdeveloped organs and heart issues.


To tell if your cat is a runt, compare its size with its littermates. You can also observe signs of weakness. There could also be deformity and disability. Also, if there is one cat that the mother cat rejects, it is usually the runt. Litter runts are sometimes rejected by their mothers because they believe they have low odds of survival and staying healthy.

In general, runts that survive to 6 to 8 weeks of age will go on to develop similarly to their littermates. If you believe your cat is a runt, take care of it. With proper nourishment and care, they can survive. 

Image: / Prystai