What causes down syndrome like signs in cats

Medically, cats are unable to have actual Down syndrome but there are some diseases and disorders that can mimic the physical characteristics that are often…

Medically, cats are unable to have actual Down syndrome but there are some diseases and disorders that can mimic the physical characteristics that are often seen in humans with Down syndrome.

What are the symptoms of ‘Down syndrome’ in cats

Although there is no such thing as a Down syndrome cat as cats can not actually have it, people associate the condition in cats with many of the following physical characteristics.

  • Wide-set eyes: eyes that are extremely far apart and usually upturned
  • Odd or abnormally shaped ears
  • Squished flat noses
  • Wide broad noses
  • Vision and hearing issues
  • Difficulty doing normal things like walking, eating, using the bathroom, or vocalizing

Why can’t cats have Down syndrome?

Down syndrome is a medical condition in humans where the person is born with an extra chromosome. Most humans are born with 23 pairs of chromosomes (46 total) and a person that has Down syndrome is born with 47 chromosomes total. This is also called trisomy and also includes other conditions like Edward syndrome and Patau syndrome.

Babies that are born with Down syndrome have an extra copy of chromosome 21.

Cats have 19 chromosome pairs (38 total chromosomes), which means they do not have chromosome 21 which is the marker for Down syndrome.

Since cats do not have the chromosome that would be a marker for Down syndrome, they can not technically have Down syndrome.

So what happend to Monty the cat?

If you are seeking to know if cats can have Down syndrome, you have most likely run across popular cats like Monty the cat or Grumpy the cat that people state look like they are cats with Down syndrome.

It is said that Monty actually does have a chromosomal abnormality and was born without a bridge bone which is why he has such a wide space between his eyes

Monty the cat

4 conditions that can cause Down syndrome-like symptoms in cats?

Although cats can not technically have Down syndrome there is such a thing as cats that are special needs.

Many times these cats suffer from other issues and conditions that mimic the physical signs of Down syndrome in cats.

1. Panleukopenia

Panleukopenia also known as Feline Distemper virus can cause some physical abnormalities in kittens that are infected in utero. The virus affects the neurological system, gastrointestinal system, and immune system.

The virus is highly contagious and has a high mortality rate but fortunately, it is rare because many cats are vaccinated against the virus.

Infected kittens may look physically normal but suffer from incomplete brain development as the virus attacks the cerebellum. While this is rare, kittens can be born with smaller than normal cerebellum, this is known as cerebellar hypoplasia.

Due to the incomplete formation of the kitten’s brain, they may lack proper functioning and not be able to do things that most kittens can like walking.

You can read more about feline panleukopenia here.

2. Cleft palate

A cleft palate is an abnormal opening in the roof of a cat’s mouth. It occurs when the two sides of the roof of the mouth fail to fuse during development.

In many cases, a cleft palate is a congenital disorder that is inherited but can also occur in utero if a pregnant cat is given teratogenic chemicals like griseofulvin.

Cats given too much Vitamin A or D can also cause cleft palate in kittens.

According to the Merck Veterinary Manual, the breeds that are most likely to suffer from cleft palate are

  • Norwegian forest cats
  • Persians
  • Ragdolls
  • Savannahs
  • Ocicats
  • Siamese

Kittens with cleft palates may have problems nursing and therefore be severely underweight or malnourished if the issue is not corrected surgically. Surgery is usually done around 12 weeks of age.

3. Hydrocephalus

Hydrocephalus is due to an increased volume of spinal fluid which causes an abnormal expansion of the head.

Kittens born with hydrocephalus may have large, round, dome-shaped heads, and neurological issues. To read more about hydrocephalus in cats here is a great article.

Causes of hydrocephalus in cats include

  • Genetic predisposition: some cats inherit hydrocephalus
  • FIP: Feline infectious peritonitis can cause many issues in the body including hydrocephalus
  • Vitamin A deficiency
  • Brain hemorrhage in newborn
  • Masses
  • Exposure to toxins in utero

4. Feline Dysautonomia

Feline dysautonomia is an extremely rare disease characterized by neurologic dysfunction in cats. It affects the autonomic nervous system which controls reflexes and other neurologic functions.

Signs include:

  • loss of appetite
  • dilated, unresponsive pupils
  • difficulty swallowing
  • droopy eyelids
  • third eyelid protrusion
  • unable to use the bathroom
  • slow heart rate
  • dehydration

How to care for a special needs cat

  • Assist them with everyday needs: A special needs cat may need more coddling than a cat that does not have special needs you may have to regularly help them eat, go to the bathroom, or groom themselves.
  • Have regular veterinary visits: Working with your vet to get the best possible care for your cat is critical
  • Protect them from potential hazards: if you have an area that could be dangerous to them like a pool make sure to keep them away from that area
  • Keep them inside: Cats with developmental issues will most likely not fare well being outside cats
  • Learn to communicate with them. If your cat is blind or deaf you may have to develop novel ways of communicating with them so they understand you


Hydrocephalus study in cats