Jack Russell Terrier on the bed

Why do Jack Russell’s shake?

Is your Jack Russell shaking now? It’s a funny old sight. However, seeing your Jack Russell shake kind of makes you want to hug them as you automatically think they could be cold. I remember when mine first started shaking; it was like a constant tremor throughout my dog’s body, and I instantly picked him up and started to cuddle him. It didn’t stop him from shaking with no effect, so I got a blanket and popped it around him; again, this didn’t stop the shakes. After a lengthy investigation, I found the reason why, or should I say the reasons why. Here I will tell you the most common cause and the other potential ones and how I resolved my dog shakes.

Jack Russell’s shake to expel excess energy that has built up. Since the Jack Russell breed has high energy levels, they need to make sure it is burnt off, and if they don’t, they tend to try to expel it by shaking or trembling. Expelling excess energy is the most common reason why they shake. However, there are a few other possibilities to consider.

Now we know the most common reason for a Jack Russell shakes; let’s also go through the other possibilities.

Serious 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 an unexplained level. Your dog will also show other signs of Hypoglycemia if this is the case. Such as lack of coordination, muscle twitching, 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 vets.

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 is an involuntary, spontaneous spasm condition that affects isolated muscles of a Jack Russell. It often affects one muscle, like the leg muscle, neck or even the eye muscle. 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 not only shaking or trembling but also several other symptoms alongside it, like diarrhoea, vomiting, increased thirst, increased 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 very tough little dogs, and they tend to hide their pain as much as they can from us. However, if the problem they are experiencing is too much, it can cause them to shake uncontrollably

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; its simple means that they are just 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 shaking time. 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 and making your Jack Russell 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 coat. It’s called double coated. The undercoat is soft, dense and fluffy, and the topcoat can be long/short and straight, sometimes rough. There are three types of coats on a Jack Russell: 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 Russells 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 quite 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.


Some of the reasons are pretty frightening above concerning the medical conditions; however, they are of extremely low percentage why dogs shake. Understanding your Jack Russell is crucial to diagnose the cause of why they shake. Remember, Jack Russell’s have double-layered coats and often don’t get cold unless freezing weather. The best thing to do is take them for a walk or give them some dedicated playtime to burn some of that energy off. Good luck. I hope I have settled your nerves and also resolved your dog shakes. Be brilliant if you could let me know, and I would very much appreciate it.


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

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