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Why Does My Kitten Run Sideways?

Kittens have to be one of the cutest creatures on earth. These tiny balls of fuzz with legs behave in the most charming and inexplicable ways. If kittens could talk, their first word would probably be ‘Awww’ because this is the word they hear from us the most.

However, certain kitten behaviors are not normal and can indicate that there is something wrong. Whether you’re a first-time cat owner or a veteran, there are certain behaviors kittens exhibit that are worth investigating. One of these behaviors is the sideways run.

Though kittens running sideways is seen as playful, it is in fact instinctual behavior. The act of running sideways is one of intimidation towards prey and is a way to bring all four sets of claws nearer to a perceived enemy for protection.

Kittens begin this running sideways behavior as soon as they begin to play with their littermates. Though running sideways day or night, is an instinctive action, it can also be a sign of vestibular disease or cerebellar hypoplasia (wobbly cat syndrome).

Fluffy tabby kitten playing with a toy mouse

The sideways run displayed by kittens is generally perfectly normal during play or in self-defense. This article provides you with full explanations of this behavior and how to tell if it’s normal or if you need to take your kitten to see a vet.

Kittens Run Sideways When They Are Playing

When kittens are playing, they often run sideways. Before they do this, they puff out the fur on their backs and tails, turn sideways, straighten their legs, and arch up their backs,

They will then either run or hop towards or away from whatever it is they are playing with. This could be a mirror, a toy, another kitten, cat, or a person.

Playful sideways running is sometimes called sidewinding or the sideways hop, and it is a very common behavior in kittens. Kittens will start doing the sideways hop from about five or six weeks of age when they are confident enough on their feet to start playing.

Kittens are often still uncoordinated, and they will crash into stationary objects, fall off beds, or even just fall over while they run and hop around.

It’s easy to know if your kitten’s sideways running is playful by the way they draw themselves up and turn to the side before running. Their tails will be pointing down but not tucked under their body.

Their ears may be pulled back but not flattened onto their heads, giving them a Batman-like expression. Their toes will be spread and their claws out.

You might not see this, but you will hear it if they are running over fabric or carpet. Their claws becoming stuck is often what causes them to fall over.

If they are running sideways because they are playful, they will not look worried or angry, and they will return to a neutral posture as soon as the game has finished.

Tabby kitten about to run sideways

Kittens Run Sideways When They Are Scared Or To Look Scary

If your kitten is frightened by another cat, dogs, noise, etc., they may also run sideways.

They will probably look very similar to when they are running sideways playfully, except that their tails can be vertically up, the hair on their backs standing up, and their ears flat on their heads.

They will also hiss and then run away after the initial sideways run response, or they will cower if there is no place to run away.

If your kitten is trying to intimidate another kitten (or something they consider prey) or is trying to look bigger in the face of a threat, they can also puff up their fur to make themselves look bigger as they run sideways.

The best way to tell the difference between playful, fearful, or intimidating sideways running is to identify what triggered the behavior and how the kittens act afterward (relaxed or nervous).

Kittens Can Run Sideways If They Have Vestibular Disease

Vestibular disease can cause kittens to run sideways. However, this sideways run will not involve deliberately turning and presenting their sides before running towards you or an object.

This sideways run will look more like they are stumbling to the side as they try to run straight. Additionally, kittens won’t arch their backs, and their hair won’t be standing on end.

Causes of vestibular disease

Vestibular disease causes incoordination. It affects the vestibular (balance) system of the inner ear and can result from infections, tumors, toxins, or certain medications.

Signs of Vestibular Disease in cats

Kittens with vestibular disease will often tilt their heads (they will run to this same side) and are very uncoordinated.

They may run sideways, in circles, fall over frequently, shake their heads, and display signs of nausea. Some kittens will also have nystagmus, in which the eyes flicker back and forth involuntarily.  

Treating Vestibular Disease

You can treat vestibular disease by treating the cause: the infection, the tumor, the toxic response. Vestibular disease will not go away on its own, and if left untreated, it can cause permanent damage.

Take your kitten to the veterinary clinic if you suspect they have a vestibular problem.

You will have to watch your kitten to ensure that they don’t hurt themself. They may also require extra attention because of the distress associated with their loss of balance and coordination.

kitten with its back up and tail puffed

Kittens Can Run Sideways If They Have Cerebellar Hypoplasia

Cerebellar hypoplasia can cause kittens to run sideways. As with vestibular disease, the sideways run of a kitten with cerebellar hypoplasia will look quite different from a behavioral sideways run.

Kittens with cerebellar hypoplasia will probably start running normally for one or two steps, then their movements will lose coordination, and their back ends may swing out to the side.

Cerebellar hypoplasia is a condition in which a cat’s cerebellum is underdeveloped. The cerebellum is the part of the brain which controls movement and motor coordination. Cats with this disease are often referred to as wobbly cats because of the way that they move.

Causes of Cerebellar Hypoplasia

Cerebellar hypoplasia is a congenital disorder; this means that kittens are born with it.

The development of the kitten cerebellum can be stunted or stopped if the kittens experience certain traumas in utero, if the mother is malnourished while pregnant, if the mother contracts the parvovirus while pregnant, or if the mother contracts feline panleukopenia virus while pregnant.

Severity of Cerebellar Hypoplasia

Not all the kittens in the litter will develop cerebellar hypoplasia. The severity of the disease in the kittens who do have it depends on when during the pregnancy the causal virus was contracted by the mother or the damage to the kitten occurred.

Cerebellar hypoplasia can be mild or severe, but it is not progressive. In some instances, it may even look like it improves as the kitten gets older, but this is actually due to the cat adapting and compensating for the uncontrolled movements.

In severe cases, cats have difficulty walking and will probably not even attempt to run. It can be heart-wrenching to watch. Severe cases will also struggle to control their head movements and may need to be stabilized by their owners when they drink or eat.

In mild cases, the kittens may look completely normal, but as they develop and grow, you might notice they are slower to reach milestones and are less confident in their movements.

Treating Cerebellar Hypoplasia

This is an incurable disease, but it is possible for afflicted kittens to lead a full life. They are generally quite happy and adapt well to their wobbly life with the right care.

Sometimes this condition can cause a build-up of cerebral spinal fluid, which can cause pain or discomfort as it puts pressure on the spinal nerves, but you can treat this secondary condition relatively easily with the help of your vet.

If you think your kitten has cerebellar hypoplasia, take them to the vet for a formal diagnosis and general assessment. You will have to research how to care for a wobbly cat as they do need extra attention and help, but they are still loving and wonderful pets.  

Ginger cat at the vets for a checkup

Do Adult Cats Run Sideways?

Cats continue their sideways running behaviors into adulthood, although they may not do it as often. They will also usually be more coordinated while running sideways because their body control and spatial awareness have improved.

Adult cats can develop vestibular disease and start running sideways. As always, take your cat to the vet if you notice symptoms or have any concerns for their health.

Cerebellar hypoplasia is not a condition that will suddenly afflict an adult cat. It is something that develops in kittens in the womb and is not curable: if you have a wobbly kitten, they will grow into a wobbly adult cat.


Kittens can run and jump sideways for several reasons. The behavioral reasons are playfulness, out of fright, and to appear intimidating. Presenting their sides and running makes these tiny felines look bigger and (in their minds) scarier.

It is adorable when your little fuzzball hops and runs sideways with their back arched, and you can elicit this playful behavior quite easily.

There are occasionally medical reasons for a sideways running kitten, including vestibular disease (which affects their balance) and cerebellar hypoplasia (an incurable neurological condition.)

Sideways runs caused by medical conditions usually look different from behavioral sideways runs so it is possible to tell when your kitten is acting normally and when it is time to take them to the vet.

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