Top 10 Animals with Down Syndrome

You might have heard of plenty of stars and overachievers of our generation with down syndrome and becoming successful despite the symptoms of the genetic disorder.
Down syndrome is one of the most common genetic disorders among humans. One in every 1000 babies is affected by down syndrome.

But have you heard of animals being affected by down syndrome? Some specific animal species go through physical and mental symptoms that seem like they’re caused by down syndrome. When it comes to conclusively determining if they have down syndrome, well, let’s just say opinions are still divided on the topic.

Regardless, we’ve come up with a list of animals that are said to have down syndrome-like symptoms in them in the article below. We’ve also touched on the other side of the story, explaining why down syndrome is possibly a myth in animals.

What Exactly is Down Syndrome

Before we get down to the list, we’d like to explain what down syndrome is. Now, we realize that most of you would already know the disorder and be intimately familiar with its symptoms.

But for those of you who don’t, down syndrome is a genetic disorder that can cause hormone deficiencies, mental disabilities and some unique physical features.
You must know this because we’re about to unveil a list of animals that have suffered from symptoms or traits similar to these ones, which should make it easier for you to identify that they indeed have down syndrome or perhaps a condition related to the disorder.

10. Cats

An animal that shouldn’t be able to have down syndrome due to its genetic makeup but has been made popular on social media as an animal that can definitely suffer from the disorder is a cat.

Cats are probably one of the most domesticated animals in the world, so it should be no surprise that any deficiency or disability in them is highly documented and often displayed on social media.

From what we could find, some cat parents have documented the early death of their cat due to what they call down syndrome symptoms, which include unusual facial features due to hormone deficiencies and genetic mutations. Among these mutations are the existence of extra toes and feline dwarfism.

9. Mice

It’s been proven that mice can develop a genetic disorder that’s similar to down syndrome. This is because of forming an additional chromosome 16 that gives them down syndrome-like symptoms.

However, these symptoms haven’t ever been experienced in the wild, as wild mice inflicted with this disorder are known to die off during infancy.

8. White Tiger

White tigers are probably one of the animals you’d least expect to have down syndrome. But unfortunately, tigers are also known to show down syndrome-like symptoms. In fact, one of the most well-documented cases of a white tiger having down syndrome is the story of Keeny, the white tiger who had physical disabilities since birth.

Keeny was rescued and brought to the Creek Wildlife Reserve in the United States in 2002, where researchers noticed that the tiger had some unusual facial features, including wide-set eyes and a mouth that wouldn’t close completely. Over time Keeny became famous on social media as the white tiger with Down syndrome. Keeny, unfortunately, passed away in 2008 in the same reserve.

Here’s a video of Keeny and how he was popular as a white tiger with Down Syndrome.

7. Dogs

Probably one of the most domesticated animals alongside cats, dogs have been well-documented to struggle with down syndrome-like symptoms too. The most common symptom that these dogs display is an abnormally large tongue. However, this could also be the result of Macroglossia, a disorder found only in dogs and typically results in enlarged cells or muscle tension. This leads to some dogs having extraordinarily long tongues, which can cause them breathing problems and reduce their range of motion.

Other than that, dogs are known to suffer from predominantly mental disabilities like slow processing of events and aggressive reactions if they are indeed afflicted with down syndrome.

6. Giraffes

The defining attribute of Giraffes has to be their incredibly long neck, so you can imagine what kind of an uproar a dwarfed Giraffe would have caused when it first appeared on social media. As unrealistic as it sounds, dwarfed Giraffes do exist with necks that are slightly larger than those of humans.

These giraffes have been labeled to be suffering from down syndrome. However, there is no conclusive proof for that theory, as these giraffes could also be afflicted with skeletal dysplasia. A bone disorder that results in unusually molded bones in the spine, legs and arms.

5. Sloths

Sloths are probably the most chill animals in the animal kingdom as they’re satisfied with living out their lives hanging upside down from tree branches.

However, these cute and fluffy creatures have been known to have down syndrome. Their symptoms are primarily of a physical nature, as sloths with alleged down syndrome often develop abnormal physical traits like extra toes or claws.

4. Koala Bears

Native to Australia, Koala Bears are another species known to have down syndrome, even though it’s never been conclusively proven. But, some males in the species have been known to develop physical disabilities and facial abnormalities like wide eyes and disfigured mouths.

These are common symptoms that people have correlated with down syndrome. Other than that, there haven’t been any documented cases of Koalas having mental problems related to down syndrome symptoms. Hence, it’s pretty inconclusive if Koalas can be afflicted with the disorder.

This video reveals some fun facts about koala bears. Check it out!

3. Lions

Can you believe it? Even the king of animals is not safe from being afflicted with down syndrome-like symptoms. However, it is worth mentioning that symptoms in lions are relatively unpronounced and don’t manifest themselves quite like some of the other animals in this list.

For example, an abnormally short mane is one symptom observed in lions who seem to be suffering from a down syndrome-like disorder. When thought about in terms of physical disabilities isn’t something extreme enough to be attributed to down syndrome.

2. Elephants

Elephants seem like pretty imposing animals, but they are incredibly soft and cushy on the inside and possess a playful affinity towards humans. These animals are suspected to be able to have down syndrome as well.

Notice we used the word “suspected” because the only known symptom of down syndrome ever observed in elephants is the abrupt loss of balance even after they’ve grown out of their childhood phase. A symptom could be caused by several hereditary disorders, not just down syndrome.

1. Bears

The last entry on this list is a bear, one of nature’s most imposing creatures. Bears can develop genetic mutations such as an abnormally large snout, tongue or wide eyes that are often compared to down syndrome symptoms. But like most of the animals on this list, there is no conclusive proof that bears possess down syndrome, as bears can have plenty of diseases that temporarily affect their facial features.

An example of a disease affecting their physical features is encephalitis, which can also cause head tilting and muscle tremors.

Why Down Syndrome in Animals is Largely Considered a Myth

Down syndrome is tricky to diagnose some humans with, let alone animals. It’s also genetically impossible for some animals to have down syndrome, including some of the animals we’ve mentioned in the list above.

But to understand fully why that is the case, we’ll first need to look at how down syndrome develops from a scientific standpoint. As we all know, the body of a living thing is made up of a certain number of chromosome pairs.

Now, the primary reason for down syndrome developing in humans is the duplication of chromosome 21 which results in an extra copy of the chromosome in the cells.
The existence of this extra genetic material can cause genetic mutations and a variety of mental and physical disabilities in humans. The reason why this can’t occur in some animals like, for example, cats is that they only possess a total of 19 chromosome pairs which means they can’t have a duplicate chromosome 21.

On top of that, the genetic makeup of animals is quite different to that of humans, so even if they did have an extra copy of chromosome 21 in their cells, there’s no reason to believe that it would have the same effect as in humans. Thus, we’d consider the existence of down syndrome in animals an inconclusive yes, due to the similarity of their symptoms but also because their genetic makeup is entirely different to ours.


By this point, you should’ve probably realized that many of the animals on the list don’t have down syndrome but another disorder that’s quite similar to down syndrome in its physical symptoms. However, nature works funnily, and there could be a possibility that each of the animals we’ve mentioned in the list is susceptible to having down syndrome.

The truth is, we can’t rule out anything without more scientific evidence to support our claim. Regardless, there is one universal truth about down syndrome that you can’t deny, and it can be defeated. And by that, we don’t mean curing it, but fighting against it and defeating it. Something that’s been proven by the millions of humans who’ve overcome the disorder and have amazed the world with their skills and abilities.

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Nadine Oraby

My name is Nadine; I am a passionate writer and a pet lover. People usually call me by the nickname “Joy” because they think that I am a positive and joyful person who is a child at heart. My love for animals triggered me to create this blog. Articles are written by vets, pet experts, and me. Thanks for visiting. Your friend, Nadine!

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