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Can Dogs Get Down Syndrome?
Updated on December 30, 2022
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Can Dogs Get Down Syndrome?
Updated on December 30, 2022
8 min read

Can Dogs Get Down Syndrome?

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Down Syndrome is a genetic disorder usually marked by specific physical characteristics (like a flattened face, poor muscle tone, etc.), potential intellectual impairment, and a heightened risk of certain health issues.

Some pet owners and dog enthusiasts have noted similar traits in special needs dogs. Just like human beings, dogs can inherit genetic disorders and other chromosomal conditions.

Some dogs may even possess physical or intellectual attributes that look like Down Syndrome. 

But can dogs get Down Syndrome like humans can? 

Quick answer: No

The number of chromosomes that humans have is different from the number of chromosomes dogs have. Humans have 23 sets of chromosomes, while dogs have 39. 

Down Syndrome occurs when there’s an extra copy of chromosome 21 in humans. In dogs, that duplication would likely have a different effect, given that the sets of chromosomes between dogs and humans don’t match up perfectly. 

In short, Down Syndrome, as we know it in human beings, there’s no scientific evidence to support its existence in dogs.3

While your dog can’t get Down Syndrome, there are other genetic disorders they can inherit that resemble it. Like any impairment or sickness, it will require special care.

In order to give your special needs dog a happy, healthy life, you need to take their genetic disorder seriously and have them checked right away.

Once you’re aware of any congenital defects or chromosomal abnormalities they may have, you can adjust their lifestyle, routines, and habits in order to best cater to their needs.

Can Dogs Get Down Syndrome? 2

What Is Down Syndrome?

Down Syndrome is a condition where a baby is born with an extra copy of chromosome 21.1

When cells divide as the baby develops, copies of chromosomes are made with each division. When abnormal cell division occurs, however, it can result in a full or partial copy of chromosomes.2

This extra copy affects how the baby develops and can pose challenges and health risks as they grow.

Some common traits that people with Down Syndrome often share are1,2:

  • Smaller (on average) body parts 
  • Loose joints
  • Short neck
  • Slower speech and delayed language
  • Memory problems (both short and long-term)
  • Higher risk for other health issues like Alzheimer’s and heart disease

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What Looks Like Down Syndrome In Dogs?

There are a few congenital conditions that resemble Down Syndrome in dogs, namely:

  • Pituitary dwarfism
  • Congenital hypothyroidism
  • Congenital hydrocephalus

Each of these conditions affects how your dog develops physically and intellectually and will determine whether or not they need special care.

Pituitary Dwarfism

Pituitary dwarfism is when the pars distalis, the part of the pituitary gland that handles the majority of hormone production, fails to develop, leading to slow growth and hormone deficiency.4

Because it affects how the pup develops, you may observe the following side effects as they grow up:

  • Short legs
  • Short jaw and/or underbite
  • Bulging eyes
  • Baldness or other skin problems
  • Skin issues
  • Tongue sticking out of the mouth
  • Larger head than normal
  • Growing at a different rate compared to others in the litter
  • Smaller than littermates
  • Teeth are slow to develop
  • Not as mentally sharp/responsive
  • Difficulty breathing
  • Poor cognitive function

This condition affects these breeds the most:

  • German Shepherds
  • Spitz
  • Miniature Pinschers
  • Karelian Bear Dogs
  • Dachshunds
  • Corgis
  • Basset Hounds

While it is a congenital disease, it can also be caused by tumors, infections, or cysts.

People often liken pituitary dwarfism to Down Syndrome in humans because of the similarities when it comes to physical traits and learning difficulties

This is, however, very different from what we recognize as Down Syndrome in humans, as this is an inherited endocrine condition and not a result of extra genetic material being abnormally copied. 

Congenital Hypothyroidism

Hypothyroidism is a condition where a dog’s thyroid gland is underactive. It’s a common condition that occurs in adulthood for many breeds.

However, congenital hypothyroidism is rarer. Instead of a thyroid gland that slowly stops performing as your dog grows, your pup is born with a gland that’s already underperforming from the beginning.

When your dog’s thyroid gland is impaired, it affects its ability to produce enough thyroid-stimulating hormone and regulate metabolism. 

This failure to create adequate thyroid hormone keeps your dog from growing at a normal rate and will affect its physical and intellectual development.

You may observe the following clinical signs in dogs with congenital hypothyroidism5:

  • Disproportionate growth
  • Bulging eyes
  • Poor appetite
  • Stomach/constipation problems
  • Teeth are slow to develop
  • Keeping their puppy coat
  • Tremors
  • Deformed or incomplete legs and smaller body
  • Goiter 

Like pituitary dwarfism, people tend to compare Congenital Hypothyroidism in dogs with Down Syndrome in humans because of the similarities in terms of physical and intellectual symptoms.

Congenital Hydrocephalus

Hydrocephalus is a condition wherein a dog suffers from an excess of cerebrospinal fluid leaking into the skull. This causes the brain to swell, putting pressure on the skull that can damage sensitive brain tissues and cause physical, neurological, and behavioral problems.6

There are two types of hydrocephalus:

  • Congenital – The dog is born with the condition and has a dome-shaped skull with a soft spot on top when they are born. 
  • Acquired – Occurs most often with swelling or the development of brain tumors.

When your dog is born with hydrocephalus, you may observe the following symptoms as they grow:

  • Downward-gazing/bulging eyes
  • Lack of response to stimuli, leading to difficulty training
  • Spasms and spastic walking
  • Seizures
  • Erratic, abnormal behavior (constant barking, tripping over self, walking in circles)
  • Lack of coordination
  • Smaller in size compared to littermates
  • Blindness or poor eyesight
  • Other physical abnormalities 

Hydrocephalus usually affects smaller, toy-sized dogs, like:

  • Boston Terriers
  • Chihuahuas
  • English Bulldogs
  • Manchester Terriers
  • Pekingese
  • Toy French Poodles
  • Yorkshire Terriers

Both the physical and intellectual developmental problems that come with congenital hydrocephalus can resemble Down Syndrome in humans, too, making people draw comparisons between the two.

How To Take Care Of Special Needs Dogs

Caring for a special needs dog requires extra patience, effort, and energy. When you find out that your pup has a congenital disorder and will need extra assistance throughout its life, here’s what you need to do: 

Get Your Vet’s Opinion Right Away

Get your vet's opinion as soon as you suspect your dog may have developmental problems. 

Your vet will observe your dog, note any developmental issues (whether physical or intellectual), and possibly run further tests to confirm a diagnosis. 

These tests can range from blood tests to thyroid tests to physical exams to see any abnormalities your dog may be suffering from.  

Genetic testing may also give you a better understanding of your dog and its ancestry, and even what else it may be suffering from (if anything).  

Impaired dogs may suffer from more than one congenital issue so getting a comprehensive diagnosis from your veterinarian will best prepare you for caring for your pup and whatever they may need.

Your vet can also inform you of what your dog may need, either diet-wise or even about their life expectancy, since some congenital defects can affect their lifespan. 

Maintain Good Diet And Exercise

Like any dog, your pup needs to be in good shape to live its best, most comfortable, and most rewarding life. This is true even for healthy dogs.

This is why you need to maintain a good diet and make sure your dog still gets ample exercise.

Impaired dogs may require special diets. Their conditions can affect the kind of food they can eat—your vet should be able to guide you around what kind of diet they need, whether it’s low-sodium or eliminating certain foods altogether.

Exercise is also crucial, so be sure to set aside time for walks and play. If your dog has any physical limitations because of their condition, take that into account. They may take more time to acclimate to regular exercise and may not even be as quick as other dogs on their feet.

Most importantly, be patient. Your dog is adjusting just as you are

Build A Routine

Dogs suffering from chromosomal abnormalities may be more inclined to anxiety, depending on their condition. 

This is why establishing a routine may help ease their worries and relieve them of any additional stress

When they know what they can expect and have a schedule laid out that they can rely on, you don’t need to worry about them panicking. Knowing when it’s time to eat, sleep, and take a walk will keep them calm, and neither of you will have to deal with anything unexpected.

Constancy and patterns can contribute to a calm environment which can minimize any erratic behavior and anxiety. 

Healthy dogs under distress can already be a handful, so make sure you can ease your special needs dog into a routine to make them feel comfortable. 

Find A Support Group

Don’t think you have to deal with this alone if you don’t have to. 

Both you and your dog can use a support group of like-minded people who may be going through the same thing

Other pet owners of affected dogs may have valuable advice for you or can even offer you a listening ear when you’re overwhelmed. They may have experience that you can rely on so you can make your dog as comfortable as possible. 

Socialization is also good for dogs, so if they can play with others, it’d be good to have them interact in a safe, calm environment.

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Updated on December 30, 2022
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6 sources cited
Updated on December 30, 2022
  1. Facts about Down Syndrome.” Center for Disease Control and Prevention.
  2. Down Syndrome.” Mayo Clinic. 
  3. Can Dogs Get Down Syndrome?” Wag Walking. 
  4. Juvenile-onset Panhypopituitarism in Dogs (Pituitary dwarfism).” MSD Veterinary Manual.  
  5. Hypothyroidism in dogs.” DVM 360.
  6. Hydrocephalus in toy breed puppies.” VCA Animal Hospitals.
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