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Why Does My Cat Arch Her Back And Run Sideways?

If your cat has arched its back and ran sideways, if it’s your first time, it could look weird, and wondering why is this happening…

Why does my cat arch her back and run sideways?

A cat may arch its back and rin sideways when it is feeling a threat from someone, or an animal. However, this can also happen with playful kittens that are still learning their boundaries. If your cat is feeling threatened you will know because this is often paired with an aggressive hiss noise.

So, now you know. But, is this the same thing as the sideways hop? Do cats puff themselves up when they are playing? How do cats arch their back so high like this? Keep reading for these answers, and much more…

2 main reasons why your cat arches her back and run sideways:

As discussed earlier cats may arch their back in this way for a couple of reasons. Therefore, in this section I will expand on this and provide more detail of these two reasons:

01. Feel threatened

If your cat sees something as a threat, for example, a rival cat, next doors dog, a fox, it will arch its back and run sideways in this manner. This is a defensive mechanism to appear bigger than normal in the hope it will make their aggressor think twice and leave them be.

This is similar to how lizards puff up their throats when they feel threatened to fend off their predator and make themselves look more of a problem for them.

02. In a playful mood

Why does my cat arch her back and run sideways?

A cat jumping and arching its back.

If you have kittens or seen them play, you may have noticed how they arch their backs when playing. This is sometimes done for fun or false alarms as they get used to their surroundings. Sometimes kittens do not understand the boundaries of playing and fighting so they will need to be trained. But, most will learn in time.

Why do most cats arch their back?

In general, cats arch themselves as a way to stretch, angle themselves as they are decending from a hop, or appear larger as a defensive tactic to their predator. Therefore, this can be used in multiple ways to benefit them depending on the scenario.

So, if you see your cat arching their back in this manner it may not always be an aggressive or defensive manoeuvre. It can be deceiving though because to the ingrained eye it can look aggressive and frightening.

Is the “sideways hop” the same thing?

The sideways hop is similar to the sideways run but slightly different. This is because they both require an arched back, but the former has the cat hoping instead of running sideways. Some may argue they are the same, but when you observe it there are subtle differences.

So, if you have heard people talk about these sideways hops before and then observed your cat arch its back and rin sideways, you now know why, in my opinion, they are different.

What does it mean when a cat runs sideways?

When a cat sideways runs it can mean that it just wants to be playful. But, if you see the cat hissing (does it do it to everyone? click here) and arching its back it could suggest it is not playing and feeling defensive. It is quite a subtle difference. But, with experience, you will notice the difference.

Anytime a cat hisses in response to your action, whether that is running sideways, hoping, responding to being stroked, etc, then this will always a sign that the cat is not happy.

Why does my cat run with his back arched?

Cats will run with their back arched when they are acting devious, shocked, or feeling defensive. If it’s the latter you may also see its hair standing on end as well. This may make it easier for you to decipher which mood it is in.

The complicated thing about this is sometimes cats are just playing and nothing more. But, if it is serious its body language will clarify this. Sometimes the body language is clear, other times it is not.

Do cats puff up when playing?

Some cats do puff up while they are playing. This is usually their tail area and can be seen by kittens as well as adult cats. To tell if it is definitely playing you will need to observe its body language. For example, it could be playfully wiggling its tail.

So, if you have seen your cat puff up its tail and assumed it is in fighting mode, think again, it could literally be interested in playing with you at this time.

What is a puffed-up tail? A puffed-up cattail looked straight with the fur standing on end. Some say it resembles a pipe cleaner.

Why does my cat arch her back and run sideways when playing

A cat may arch its back and run sideways when it’s playing because it is simulating fighting. This is usually seen in younger cats, or kittens who are learning how to conduct themselves and are generally more playful than an established or senior cat.

So, if you have seen your cat acting like this and wondered why this is necessary when they are playing, you have an idea of why and what kind of cats are likely to act this way.

How can cats arch their back so high?

Cats can arch their backs so high because of the vertebrae bones they have. Firstly, they are loosely formed to give them maximum flexibility. Then they have nearly double vertebrae as us, humans, at 60, compared to 34. This allows them to arch at such a step angle.

If you have never heard of vertabreae before they are the circular looking bones that form in a line to make aspine. They are in most mammals. No doubt if yu have seen a skeleton model you have seen them without knowing.

So, if you have ever looked at a cat’s arched back and wondered how they got so high then this explanation should make it a bit clearer for you to understand.

How do you know if your cat is serious or just playing?

Why is my old cat acting like a kitten?

A cat jumping up after a toy.

To tell if your cat is arching its back as a form of defense or just playing you need to look out for its body language and noise it makes (what if it huffs? click here). For example, if its teeth are displayed, in a menacing way, and it’s hissing, then this is a clear sign it is not playing games.

However, If you do not see, or hear this, then this is an indication that the cat could be just playing around and means no harm, or does not feel threatened.

If you play rough with your cat, for example roughing up its fur, putting your hands around its mouth etx, sometimes thsi can esculate from playfulness to a similar but more serious defensive stance. This i different, this has escalated from playing into defensive aggression.

Lindsey Browlingdon