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12 Reasons for a Dog’s Front Leg Shaking When Sitting

Have you noticed your dog’s front leg shakes when sitting? Front leg shaking can indicate behavioural or medical issues, so it’s not something to ignore.

In this article, we’ll discuss the most common reasons for a dog’s front leg shaking while sitting. We’ll also explore whether it’s normal for a dog’s leg to shake and when to contact a vet.

Is It Normal for a Dog’s Leg to Shake?

A dog’s legs can shake for a variety of reasons. While these reasons aren’t always serious, it’s still not normal for a dog’s leg to shake regularly.

There are three broad categories when it comes to reasons for leg shaking:

  • Behavioural. If the dog is scared or anxious, stress hormones are released into the body as part of the “flight or fight” response. These can cause the dog’s legs to tremble or shake.
  • Medical. Any condition affecting the nervous system may lead to front leg shaking. Pain is also a common reason for leg shaking.
  • Environmental. Shivering can also be caused by something in the dog’s environment, such as cold weather.

You should always contact a vet if you notice your dog’s front leg shaking – particularly if it happens regularly or for an extended period.

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Shaking, Twitching and Shivering – What’s The Difference?

When reading about canine health conditions, you’ll often see the words shaking, twitching and shivering used interchangeably. There are actually differences between them though:

  • Shaking is a continuous and repetitive movement. It’s involuntary and is often in response to pain or stress.
  • Twitching is an infrequent and sporadic movement of the limb. You’ll often see a dog twitching when dreaming, but it can also be caused by medical conditions.
  • Shivering is when the dog’s muscles tense up to generate heat during cold conditions.

13 Reasons for a Dog’s Front Leg to Shake When Sitting

12 Reasons for a Dog's Front Leg Shaking When Sitting

1. Pain

When a dog is in pain, there will often be higher levels of stress hormones and adrenaline in the blood.

These can cause the front limbs to shake – especially if the pain is localised to the leg or shoulder joint. The dog’s front leg may also shake when they put weight through it, which could be why you notice shaking when they are sitting (rather than lying down).

It can be hard to tell when a dog is in pain, as they naturally hide discomfort. Look for other possible symptoms, such as chewing at the area, limping, or changes in behaviour.

Always visit a vet if you suspect your dog is in pain. There are many potential causes, ranging from an acute injury, to diseases like distemper and arthritis.

2. Cold

An obvious reason for a dog’s leg shaking is that they are cold. Just like humans, dogs shake to generate body heat and stay warm.

Shivering due to cold temperatures usually won’t be localised to the front legs. However, this might be where the shivering is most obvious when your pet sits down.

3. Excitement

Some dogs tremble or shake with excitement when they think something fun is about to happen. For example, you might notice your dog’s leg shaking when it’s almost mealtime, or when you get home from work.

Shaking due to anticipation is most noticeable in the front legs, as dogs often sit when waiting. It should quickly stop once the dog calms down again.

Note: Any dog can shake with excitement, but it’s most common in puppies or adolescent dogs. 

4. Stress

Stress causes the dog to become tense and alert.  In some cases, this may lead to the dog shaking, due to elevated levels of adrenaline in the blood.

Aside from shaking, other symptoms of stress in dogs can include lip licking, yawning, whimpering, pacing, panting, and a tucked tail. For more examples, read our guide to stress in dogs.

While a certain level of stress is normal for dogs, you should always visit a vet if your pet is regularly shaking due to stress. Chronically high levels of adrenaline and cortisol can cause various health problems and affect your dog’s quality of life.

Note: There is a difference between shaking and shaking off. Dogs often give an exaggerated “shake off” when they are trying to relieve stress, but this is a deliberate behaviour. In contrast, shaking is continuous and involuntary.

5. Fear

Similarly to stress and pain, a fearful dog will experience increased adrenaline levels. This can cause the front legs (and other body parts) to shake.

There are many potential causes of fear in dogs. Common examples include loud noises (such as fireworks or thunder), other dogs, arguments in the household, or an unfamiliar environment.

6. Drop in Blood Sugar Levels (Hypoglycemia)

A dog’s body needs a continuous supply of glucose to meet its energy requirements. When sugar levels in the blood drop below the required amount, the dog experiences a condition called hypoglycemia.

Hypoglycemia can cause a range of symptoms. Aside from shaking, these can include a loss of appetite, lack of coordination, vomiting, and even seizures.

Always take your dog to the vet if you notice any of these symptoms. Hypoglycemia is a medical emergency that can be fatal if it isn’t treated properly.

7. Poisoning

Poisons cause different symptoms, depending on the type of poison and how much was consumed. Shaking is a common sign of poison though, including in the front legs.

Here are some examples of poisons that could potentially cause shaking in the front legs:

  • Caffeine
  • Mould
  • Xylitol
  • Chocolate
  • Garden pest control products
  • Macadamia nuts

You should take your dog to the vet immediately if you think they’ve eaten poison. Many poisons can be fatal if the dog doesn’t get quick treatment. Remember, just because something is safe for humans to eat, doesn’t mean it’s not highly poisonous to dogs.

8. Generalized Tremor Syndrome

Generalized tremor syndrome (GTS) is a mysterious condition that was first seen in small, white breeds (such as shih tzus or West Highland terriers). However, it has since been discovered that GTS can affect any breed, regardless of size or colour.

GTS is thought to be an autoimmune condition. It causes the dog to chronically shake, either in a specific body part (such as the front leg) or the whole body.

While GTS isn’t curable, the symptoms can be managed through the use of steroids. The condition usually becomes noticeable during adolescence, so you should always visit a vet if your pet starts to shake more as they emerge from the puppy stage.

9. Addison’s Disease

Addison’s disease is a serious condition that means the dog’s adrenal glands can’t produce enough stress hormones. It can sometimes cause leg shaking, along with a range of other symptoms.

In a healthy dog, cortisol and other hormones are produced whenever the dog is exposed to a stressful situation. These hormones allow the dog to respond to the situation, by activating the flight or fight response. But in dogs with Addison’s disease, there aren’t enough of these hormones produced for the dog to cope.

This means that even minor situations can cause serious health problems. In some cases, the dog may even die, as they can’t produce enough hormones to cope with a stressful situation.

Symptoms of Addison’s disease are often difficult to spot, as they mimic other conditions. Some of the most common include lethargy, loss of appetite, diarrhea, and vomiting. 

Addison’s disease can also cause hypoglycemia, which, as we mentioned earlier, can cause your dog’s limbs to shake.

If your vet suspects Addison’s disease, they’ll often perform various tests, along with a thorough examination of your pet’s medical history. Treatment is usually successful if the disease is properly diagnosed.

10. Cerebellar Hypoplasia (Puppies)

If you’ve noticed that your puppy’s front legs are shaking, then a condition called cerebellar hypoplasia could be the cause.

Cerebellar hypoplasia is a neurological condition that’s caused by the cerebellum not developing correctly. As this region of the brain is involved in movement and balance, a lack of development can cause the dog to become clumsy and have difficulty walking.

The first signs of cerebellar hypoplasia tend to become noticeable when the puppy is around two weeks old. As the puppy starts to explore their environment, they’ll appear clumsy and unsteady (even more than most puppies).

Cerebellar hypoplasia can also cause various other symptoms, including tremors and shaking of the front limbs. The dog may also fall over or find it difficult to judge distances.

While cerebellar hypoplasia is incurable, it doesn’t get worse over time. There are also many tips and techniques you can use to help your pet live a happy life, which your vet can help you with.

11. Hypomyelination (Puppies)

Another potential cause of a puppy’s front legs shaking is hypomyelination.

Hypomyelination is sometimes known as “shaking puppy syndrome.” It happens when the dog’s body can’t produce enough myelin, which is a fatty tissue that covers the nerves and ensures messages from the nervous system are carried correctly.

Symptoms of central nervous system (CNS) hypomyelination are first noticeable a few days after a puppy is born. Typically, CNS hypomyelination starts by causing body tremors and shaking, which get worse when the puppy is active.

The good news is that these symptoms usually resolve when the puppy reaches around 12 months old. 

Hypomyelination can also affect the peripheral nervous system, which causes symptoms such as weakness and lack of coordination. Unlike CNS hypomyelination, the symptoms don’t get better with age, although the dog is still likely to have a regular lifespan.

12. Canine Cognitive Dysfunction (Senior Dogs)

Canine cognitive dysfunction (CCD), which is sometimes called canine dementia, is a potential cause of front leg shaking in senior dogs.

The symptoms of CCD are initially mild, but gradually worsen over time. While CCD probably won’t cause shaking directly, it can increase anxiety, fear, stress, and confusion, which may lead to front leg shaking.

Other potential symptoms of canine cognitive dysfunction include:

  • Disorientation
  • Pacing
  • Changes to sleep routine (including waking and barking at night)
  • Difficulty learning new cues
  • Loss of house training
  • Excessive licking
  • Changes to behaviour

When Should You Contact a Vet?

You should always contact a vet if you notice ongoing front leg shaking. You should also seek veterinary advice if your dog’s leg shakes for an extended period of time, or if you notice any other signs of illness.

There is a huge range of potential reasons why your dog’s front leg might shake when they are sitting. It’s important to rule out medical causes first, as these can have the most serious consequences.

Once you know that leg shaking is not a medical problem, you can assess the dog’s environment to check whether something is making them anxious, stressed, or fearful.

Tip: Record a video of your dog’s leg shaking. This helps your vet understand exactly what’s happening and makes it easier to get an accurate diagnosis.


A dog’s front leg shaking can indicate a medical condition, such as pain, poisoning, hypoglycemia, and hypomyelination. But it can also signal a behavioural issue, such as anxiety or stress.

You should discuss leg shaking with your vet. While a shaking front leg isn’t always a sign of a serious condition, it’s important to rule out medical causes.

Do you have any questions about why a dog’s front leg shakes when sitting? Please let us know in the comments section below.


Richard Cross

Richard is a journalist who specialises in dog behavior. He's written hundreds of articles and books related to dogs, including for the Continental Kennel Club, Dog Fest (the UK's biggest dog festival) and various veterinary surgeries. When he's not spending time with Jess and Rudy (his beloved Labrador and Golden Retrievers), he enjoys reading, hiking and watching sports.
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