Sometimes the trembling, shaking or shivering in a dog happens on its own, and other times the shaking is accompanied by other signs.
The aim of this article is to summarise the reasons for dogs shaking or trembling and to help you understand more about what’s happening with your pet.
Why do dogs shake, shiver or tremble?
Shaking, shivering and trembling do not happen randomly. They are signs that are caused by something that may not be obvious. The broad causes include:
Cold: It’s a natural physiological response for the body to shiver when cold. The rapid, small, muscle movements generate heat, warming the body up again. If this is the cause, your dog will stop shivering when they are in a normally warm room. To prevent recurrence, you need to take steps to prevent hypothermia in your pet (e.g. keep them in a warmer room, or use insulated clothing to keep them warmer).
Fever: Most of us have experienced feeling shivery when we have a high temperature, and sometimes dogs may react in the same way. If your dog has a fever, they will usually show other signs of illness, such as a lack of appetite and dullness.
General disease: A long list of possible diseases can cause an animal to start shaking. In such cases, the shivering animal will generally have other signs of illness, or the shivering will be so severe and continuous that you should take them to the vet. When you do this, part of the work of the vet is likely to be investigations to rule out a wide range of underlying conditions. Diseases that are known specifically to cause shivering include Addison's disease (hypoadrenocorticism), kidney disease, diabetes mellitus and pancreatitis.
Poisoning: A number of poisons can affect the body by causing trembling or shaking, along with other signs. It’s important to check for the possibility that your shivering dog may have been exposed to some sort of poison, whether from eating, from physical contact or even from inhaling something. Again, there will normally be other signs of unwellness and so a pet with suspected poisoning is likely to need to go see a vet. If there are enough clues to suggest that toxicity of some kind may be involved, your vet may need to contact your local animal poison control for more information.
Neurological or muscular disease: Muscle function is controlled by the basic communication system of brain to spinal cord to nerves to muscles, with neurotransmitters carrying the nerve impulses from section to section. Any disease that interferes with these systems can cause shivering and muscle weakness. A pet with this type of problem is likely to develop shivering that is sufficiently severe and continuous that a visit to the vet is obviously necessary.
Seizure disorders: Like humans, dogs can suffer from diseases that cause partial seizures, which can present as trembling, shivering or shaking. In such cases, the shivering is likely to happen intermittently, with the dog appearing normal in between episodes. If you suspect this may be the case in your pet, you need to visit a veterinarian to discuss it in more detail.
Pain: Animals suffering from different types of pain can shiver as a reaction. Examples include arthritis, spinal pain and abdominal discomfort. Dogs cannot communicate pain to us verbally, so it can be difficult to sort out this type of diagnostic challenge. Sometimes vets will examine an animal, looking for a particular focus of pain (e.g. by moving a joint and seeing if a dog reacts). In other cases, a vet may put a dog onto pain relief, to see if this stops the shivering.
Old age: As dogs get older, they shiver or shake more than younger dogs, for various reasons. If your elderly dog shivers, it’s always important to have them checked by a vet so that you are sure there is no underlying cause that needs treatment. If no cause is identified, your dog could suffer from essential tremor (ET), also called benign tremor, familial tremor or idiopathic tremor. This is a benign condition where, for unknown reasons, there are involuntary rhythmic contractions and relaxations (shivering or twitching) of certain muscle groups. In dogs, this does not need to be treated, but understanding that this is a harmless, pain-free condition of an elderly pet can make it easier for people to accept it.
Is it a sign of muscle weakness or injury?
If an animal suffers from an accident of any kind (e.g. a fall, a sprain, a road accident or a dog fight), they will often shiver afterwards, for a combination of reasons, including excitement, fear, shock and pain. This shivering may settle down rapidly. If it does not, you should take them to the vet. This is, of course, a separate issue to any other injuries they may have sustained, which may mean a visit to the vet in any case.
Or excitement, fear, anxiety or learned behaviour?
There are a number of physiological conditions (i.e. not disease) that can cause dogs to shiver, tremble and shake.
Excitement: Trembling is a normal reaction to excitement in many situations. I know that my own dog shivers with anticipation as we approach her favourite place to go for a walk. If your dog only shivers at times when they are excited, this is nothing to worry about.
Fear and anxiety: Dogs that are fearful or nervous often shiver. I know some dogs that start to tremble when their owners drive past their local veterinary clinic.
Learned behaviour: When some dogs are outside on a cold day, wanting to come inside, they may use shivering to persuade their owner to let them in. This can be proven by noting that if they are observed, but not aware that they are being observed, they won’t shiver. But as soon as they see their owners watching them, they begin to shiver violently. Some dogs learn in other situations that if they shiver, they get attention and treats, so they may learn to shiver simply to be rewarded, even when nothing’s wrong.
What other signs should I be watching for?
Whenever any animal shows any unusual signs like trembling or shivering, it makes sense to observe them generally more closely than usual. Monitor their behaviour, make sure that they are eating and drinking normally, and keep note if you notice anything at all unusual. In particular, check for unusual signs such as difficulty breathing, coughing, increased thirst, vomiting or diarrhoea.
When to see a vet
If, at any time, you are worried about your dog trembling, shivering or shaking, then you should take them to a vet to be checked carefully.
If your shivering dog fits into one of the categories above (e.g. excited, nervous, anxious, fearful, learned behaviour, or even an elderly dog shivering occasionally), then there’s no need to rush to a vet – you can discuss this as part of their general annual health check or at your next visit to the vet for another reason.
If, from reading above, you suspect your dog may be shivering for a more serious underlying reason, then a visit to the vet makes sense. Remember to take a video of your pet shaking, so that you can show the vet exactly what has been happening. Also, keep a written record so you can explain the time scale clearly to the vet.
Treatment of shaking in dogs
Some types of shaking do not require treatment: simply knowing that the cause is benign is sufficient. However, if there is a more serious cause, then treatment may be needed, ranging from pain relief, to anti-seizure medication, to specific treatment for an underlying disease.
How to prevent shaking in dogs
There are so many possible causes of shivering and shaking in dogs that it’s impossible to make specific recommendations for how to prevent this. The only easily preventable cause of shivering is cold: make sure that your dog does not become over chilled at any time. Check that their nighttime accommodation is sufficiently heated, and perhaps get them used to wearing an insulating jacket if there are times when they are likely to be exposed to the cold (e.g. going for a walk on a bitterly cold day).
