Have you ever noticed your Jack Russell shaking? It’s quite a peculiar sight. When you see your Jack Russell trembling, your first instinct might be to wrap them in a loving embrace, assuming they’re chilly. I recall the first time my Jack Russell started shaking, his entire body rippling with tremors. Without hesitation, I scooped him up for a comforting cuddle. However, his shakes remained unaffected.

Following an extensive search for answers, I finally uncovered the reasons behind this behaviour. Below I’ll share the most common causes and the other potential factors in hopes that it helps you understand – and potentially resolve – your Jack Russell’s shakes.

Jack Russell Terriers often shake as a way to release built-up energy. This breed is typically bursting with vitality. If they fail to burn this energy off, they may end up shaking or trembling in an attempt to expel it. This is the primary reason why they shake. However, it’s worth noting that there could also be other contributors to this behaviour.

We now understand the most common reason why a Jack Russell shakes. However, let’s also explore other possible causes.

Severe medical conditions (Rare)

Please don’t be alarmed by the possible medical reason your dog shakes. Likely, your dog doesn’t have any of the below conditions. However, there is always a tiny chance, so it is best to educate yourselves, and this way, you can check for signs and rule it out.


Jack Russells can suffer from Hypoglycemia. It’s when their blood sugar levels are of unexplained level. If this is the case, your dog will also show other signs of Hypoglycemia. Such as lack of coordination, muscle twitching, and weakness, and they can also get discolouration on the skin and gums. If your dog is shaking and has these other symptoms as well, then it’s a trip to the vet.

Wobbler Syndrome

Wobbler syndrome is a condition that affects the cervical spine, and the compression of the spinal cord can result in excessive shaking in dogs. But this is very rare for Jack Russells; however, it is something to be made aware of.


Myokymia is an involuntary, spontaneous spasm condition that affects the isolated muscles of a Jack Russell. It often affects one muscle, like the leg, neck, or even the eye. The condition is mainly due to lack of sleep, dehydration, fatigue, over-exercised and anxiety.

Addison’s Disease

Please don’t panic, as it’s scarce in dogs. However, it’s slightly more common in girl dogs. Addison’s disease is shaking or trembling and several other symptoms, like diarrhoea, vomiting, increased thirst, urination, and even unexplained weight loss.

If you think your dog has any of the medical conditions above. You must see a veterinary professional as soon as possible and get it diagnosed, treated or ruled out.

Common possibilities


Jack Russells are remarkably resilient small dogs, often masking their discomfort from us. However, if they are dealing with an overwhelming issue, it may result in uncontrollable shaking.

Old Age

Old dog laying on bed and text saying 16 years old
My Jack Russell Pippy at 16 years old

Jack Russells, unfortunately, grow old, and I know this too well, and it’s a sad fact that they aren’t around forever. But this can also be a possibility as to why they shake. It doesn’t mean they are sick or in pain or have a medical condition; it simply means they are old and frail.

Recommended Read: How Can You Tell How Old A Dog Is? (Home Checks)


  • Fear can make your dog shake
  • Anxiety can make your dog shake
  • Excitement can make your dog shake

Think about what is happening around your dog at the time of shaking. Has your Jack Russell just had a traumatic event? Perhaps they have been left at home alone for too long, or maybe the kids are overplaying with your dog and making your Jack Russell too excited. If so, then this could be the reason why.


If your Jack Russell is cold, they will shake like us humans, but let’s not forget they have two layers to their coats. It’s called double-coated. The undercoat is soft, dense and fluffy, and the topcoat can be long/short and straight, sometimes rough. A Jack Russell has three types of coats: smooth, broken, and rough. So if you are not cold and your lips aren’t blue, your Jack Russell will certainly not be cold.

Excessive energy – (The Most Common Reason)

The most common reason that Jack Russell’s shake is to expel excess energy. The temperament and personality of Jack Russell make this very common in them, and it doesn’t harm your Jack Russell in any way, shape or form. They are naturally hyper dogs, and they love to be active. They love to be out and about digging and searching.

How I resolved my Jack Russell from shaking

Jack Russell walking on the beach
Take your Jack Russell for a walk.

It was pretty simple, my JRT, named Pippy, needed to expel some extra energy, so the best way to do that was to take him for a walk. We had a nice long walk, and when we got back home, we chilled on the sofa, shake-free.


The reasons related to medical conditions mentioned above, which may seem alarming, actually have a rare occurrence in causing dogs to shake. Therefore, understanding your Jack Russell’s behaviour is pivotal to accurately identifying the cause of their shaking.

Remember that Jack Russells have two coats and don’t get cold unless it’s really freezing. One good way to help them is to take them for a walk or play with them. This will use up some of their energy.

I hope this helps and your dog stops shaking. Please update me on this. Good luck.


Read this for more information on the breed, Jack Russell Terrier Personality.

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