Can Cats Have Down Syndrome?

Cat that is grumpy and easily offended

We love our cats, and it’s only natural that we apply the same characteristics and emotions that we feel on a daily basis to our feline companions. But, can cats be born with human conditions like Down Syndrome or Autism, or are these medical conditions strictly limited to a cat’s human counterpart?

We’ve gone in-depth with our research to answer the question, “Can cats have Down Syndrome?” to be able to give you a clear and definitive answer. We’ll tell you everything you need to know about Down Syndrome and why cats can or can’t have this condition.

Understanding How Down Syndrome Occurs

In order to answer your question, we have to define what Down Syndrome is first, and we’ve broken this answer down to make it as simple and as clear as possible.

When all living things get pregnant and give birth, they pass down copies of their genetic material to their offspring, and this genetic material comes in pairs called chromosomes. Every plant and animal species on earth has its own specific number of chromosomes that come in pairs.

For example, humans have 23 pairs of chromosomes, alligators have 16 pairs, cherries have 16 pairs, and cats have 18. As species continue to reproduce and pass their genetic material on, the chromosome pairs don’t change, and they stay the same.

Each parent passes on one chromosome per matched pair, and this helps to ensure that their offspring get equal matching sets of chromosomes. Once in a while, something goes wrong when the parents pass the chromosomes down, and the offspring receives three chromosomes instead of the original two.

When the offspring gets three chromosomes instead of two, this typically creates some kind of genetic disorder, and it’s called trisomy. Specifically, in humans, when a trisomy happens with chromosome 21, you get the genetic disorder known as Down Syndrome.

Common Traits Associated with Down Syndrome

Now that you know how Down Syndrome can occur in people, we’ll go over some of the common traits that can present with this condition. Since cats can mimic some of these traits, it’s easy to see why people may assume that their cat has Down Syndrome.

People with Down Syndrome usually have several physical features that set them apart, and certain conditions cats get can mimic these same psychical features. For example, people with Down Syndrome can have larger tongues, slanted eyes, outer ears that are abnormal, small chin, one crease in their palms, and a short neck.

They also usually have poor muscle tone, and their growth may be stunted, and this leads to a shorter stature and possibly coordination problems. Additionally, people with Down Syndrome have an impaired mental ability, and this usually puts their IQ around 50 or that of a nine-year-old child.

There are also greater health risks, and they tend to develop slower than their peers. However, this can vary drastically from person to person, and no two people with Down Syndrome are alike.

Conditions That Can be Mistaken for Down Syndrome in Cats

For cats, there are several conditions that they can have that may lead you to believe that they have Down Syndrome. These include:

Cerebellar Hypoplasia

Cerebellar Hypoplasia is a condition where your cat’s cerebellum doesn’t develop as it should, and this can cause several issues with motor control. For example, your cat could have trouble walking or standing, have leg tremors, be generally clumsy, or tend to bob their head when they walk.

This condition can be from a birth defect, but it can also be caused by poisoning, bacterial infections, or malnutrition. There is no cure, but this condition usually doesn’t get work as your cat ages either, and it’s relatively easy to manage once you get a diagnosis.

Distal Polyneuropathy

If your cat has diabetes, they can develop Distal Polyneuropathy, and it’s a common type of nerve damage that presents in the cat’s feet as numbness or pain. If your cat has this condition, they’ll usually experience seizures, loss of motor control, tremors, paralysis, weakness, and an unsteady gait.

You can manage this condition with nutritional support and electrolyte therapy, and it may go away depending on what is the root cause. However, cats who have congenital polyneuropathy typically don’t live long, and you diagnose it through blood and urine tests.

Facial Deformities

Some cats can be born with facial deformities or a form of dwarfism that makes their faces look odd. For example, some cats are born with too small jawbones, missing nasal bridges, or other issues that make them look like they could have Down Syndrome.

However, facial deformities can be caused by genetic conditions as well as inbreeding or accidents. They don’t come from the cat having a form of Down Syndrome.

Feline Dysautonomia (Key-Gaskell Syndrome)

If your cat’s autonomic nervous system malfunctions and causes swelling in the gastrointestinal and urinary tracts as well as droopy eyes, your cat could have Feline Dysautonomia or Key-Gaskell Syndrome. Cats diagnosed with this condition can also have a dangerously slow heart rate, depression, weight loss, lack of appetite, and incontinence.

Your vet has to diagnose this condition, and there is no known cure for it. However, you can treat and manage the symptoms so your cat can live a relatively normal life.

Klinefelter Syndrome

Klinefelter Syndrome occurs in roughly 1 in every 3,000 male cats, and this syndrome is usually present in the rate male calico cat. Basically, any cat with this syndrome was born with an additional X chromosome, and it can cause slight behavioral changes as well as sterility.

However, there is usually only one behavioral change that people notice, and this is that their male cat tries to entice other male cats to mate with them. Otherwise, he should behave as a typical cat would.

Do Cats with These Conditions Have a Form of Down Syndrome?

Since Down Syndrome occurs when the 21st pair of chromosomes has a trisomy and cats only have 18 pairs, cats can’t technically have Down Syndrome. But, can they have a feline version of this condition when a trisomy occurs in another pair of chromosomes?

According to Professor Leslie Lyons of the University of Missouri School of Veterinary Medicine and Surgery, the answer is still no, your cat can’t have a version of Down Syndrome. This is because the genes that make up the 21st pair of chromosomes on a person are called C2 in your cat.

C2 is much larger than chromosome 21, and it has a significant number of genes that chromosome 21 isn’t large enough to have. So, if an abnormality like a trisomy occurred in C2, there were be far too many complications for that embryo to survive because it’s too big for your cat’s body to sustain it.

The only documented trisomy that rarely occurs in cats is when a male cat has calico coloring, and the cat is born being sterile. This happens when the cat has three sex chromosomes instead of the traditional pair of sex chromosomes, and it’s referred to as Klinefelter Syndrome.

Understanding the Technicalities

There are several terms and technicalities floating around concerning cats and Down Syndrome. It can lead people to believe that Feline Down Syndrome is a thing when it’s not.

1. Cats and Humans Have Different Chromosomes

As we mentioned earlier, cats only have 19 pairs of chromosomes while humans have 23, and it’s an extra chromosome at pair 21 that causes Down Syndrome in humans. This simply isn’t possible for cats because they have fewer chromosomal pairs with 38 individual chromosomes.

It isn’t physically possible for them to have the extra chromosome at pair 21 because it doesn’t exist. Also, the chromosome structure that your find in cats is significantly different than the chromosome structure that you find humans.

2. Behavioral Oddities Don’t Automatically Mean That Your Cat Has Down Syndrome

A lot of the time, people compare their cat’s behavior to other cats, and they may notice that their cat sits weird, meows weird, is clumsy, or has trouble balancing as they walk or stand around. Many people see this and automatically think that there is something medically wrong with their cat and they assume it has a condition like Down Syndrome.

However, these odd behavioral traits can simply be your cat’s personality or traits. Also, a lot of the time dysfunctional behavior is a key indicator that there is something going on with your cat in a medical sense, and this can range from a simple urinary tract infection to something more severe.

3. Misdiagnoses are Common

If your vet misdiagnosis your cat with Down Syndrome, it could be because your veterinarian isn’t aware of other genetic conditions or mutations that could cause your cat to look or act as it does. Most of the time, irregular facial features are the cause of a Down Syndrome misdiagnosis, and it’s one of the common signs that the cat owners use to claim that this is what is wrong with their cat.

Just like their vet, they may not realize that there are other genetic mutations like Klinefelter Syndrome that can trigger a facial deformity or irregular features. As there is no significant evidence to prove that Feline Down Syndrome exists, your vet should always do their research before misdiagnosing your cat with this condition.

4. Inbreeding Causes Facial Irregularities or Deformities

Breeders may attempt to breed two litter mates together to keep desirable traits, and inbreeding is common for cats if they’re left to their own devices. However, when two cats with the same genetic structure produce offspring, that offspring’s chances of having irregular facial features doubles.

This risk includes passing on diseases, health problems, or recessive traits that may be undesirable to the offspring, and this risk drops down to half when the cats breed outside of their family lines.

Celebrity Cats Thought to Have Down Syndrome (and What They Really Have)

There are several popular cats on the internet and social media that are widely thought to have Down Syndrome. Their facial irregularities cause people to think this incorrectly, and there are explanations for all of them.

  • Grumpy Cat – In 2012, a photo of Grumpy Cat (Tardar Sauce) was posted showing her irregular face, and it quickly went viral and gained massive popularity. Videos show her having a slightly odd wobble when she walks, and she tends to sit a bit odd, but this is widely considered to be from a form of dwarfism.
  • Lil Bub – In 2011, Lil Bub was born with a variety of abnormalities including an extra toe on each foot, bulging eyes, no teeth, a significantly shorter lower jaw, and her tongue hangs out. She has an extreme form of dwarfism that causes most of these issues, and it gives her a very unique look.
  • MontyMonty has a genetic abnormality that caused him to be born without a nasal bridge, and this gives him unique facial features. Additionally, he also has some special needs that require ongoing care like going to the bathroom in his sleep.

Bottom Line

So, can cats have Down Syndrome? The answer is no. Feline Down Syndrome does not exist, even though there are some people that claim it does, and it is often used as an unofficial diagnosis for other genetic abnormalities or facial irregularities. However, cats can have other genetic disorders that can mimic the physical traits that are common with Down Syndrome in humans.

It’s always a good idea to talk to your vet if you think something is wrong with your cat because they’ll be able to find the root cause of your cat’s physical or behavioral abnormalities. If you find the cause, you’ll be able to manage it and help your cat live a long and happy life.