What this means
Shivering is muscle activity, not an illness in its own right. A dog may shake from cold, from fear or excitement, from pain, from tiredness after hard exercise, or because the body's chemistry has shifted. Some smaller breeds shake more readily and for no particular reason, so the useful comparison is with what is normal for that individual dog.
It is worth separating shivering from a seizure. A shivering dog stays conscious, responds to its name, can walk, and will do a familiar command if asked. During a seizure, awareness is lost, the muscles stiffen or jerk rhythmically, the dog may fall on its side and pass urine involuntarily, and afterwards be confused for a while. That is a different picture and a different level of urgency.
One combination deserves separate attention: shaking together with not eating. Shivering alone may be brief, but alongside a lost appetite it more often points at pain or at feeling generally unwell. If lethargy, vomiting or a tense belly join it, this is not something to wait on.
Possible causes
These are things that can cause this sign. It is not a diagnosis, and they are not equally likely for your dog.
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Cold, a wet coat or tiredness
After a walk in the rain, a bath or a long spell outdoors, shivering is how the body warms itself. It stops once the dog is warm and settled.
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Fear, tension or excitement
Thunder, fireworks, a journey or unfamiliar surroundings cause shaking along with hiding, pacing or climbing onto you. It passes as the dog settles.
About the condition: Anxiety -
Pain
Dogs show pain quietly, and shivering can be one of the few outward signs. Reluctance to move, an altered posture or avoiding being touched often go with it.
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A drop in blood sugar
In very small puppies and toy breeds, too long between meals can cause shaking, weakness and wobbliness. This needs urgent attention.
About the condition: Hypoglycemia (low blood sugar) -
Poisoning
Some household and garden substances, plants and human preparations cause shaking and muscle twitching. If there is any suspicion your dog swallowed something, this is urgent.
About the condition: Poisoning -
Overheating or a raised temperature
A raised body temperature can show as shivering alongside heavy panting and lethargy. On a hot day or after exercise, that needs assessing quickly.
About the condition: Overheating (heat stroke)
What else to watch for
These observations help your vet build the picture faster. Note down what you saw and when.
- Whether your dog stays conscious and responds to its name
- Whether it can walk and stand normally
- Whether it is eating and drinking as usual
- Whether the shaking stops once warm and settled
- Whether there is vomiting, laboured breathing or a tense belly
- Whether your dog could have swallowed something indoors or outside
When to book a routine visit
Book a visit if the shaking keeps returning, if it does not stop once your dog is warm and settled, or if appetite, getting up or willingness to move have changed with it. If it came on suddenly alongside lethargy or vomiting, be seen the same day.
Related conditions
Conditions whose entries mention this sign. The list is somewhere to read on, not a way to reach a diagnosis.
- Anxiety General health Anxiety is a state in which a dog feels tension and fear constantly or far too strongly, even when there is no real danger. It can be set off by being left alone, loud noises, new surroundings or strangers, and long-lasting anxiety wears down both the dog and the whole household. It helps to understand that this behaviour is not stubbornness or disobedience but a sign that the dog is struggling.
- Hypoglycemia (low blood sugar) Hormones and metabolism Hypoglycemia is a condition in which the level of glucose in the blood drops too low and the brain and muscles run short of energy. It can affect young puppies and small dogs, especially if they have gone a long time without food or are exhausted, as well as dogs with certain diseases. Hypoglycemia can quickly become life-threatening, so the dog needs a vet immediately.
- Epilepsy and seizures Nerves and muscles A seizure is a sudden disturbance of the brain's electrical activity that can make a dog twitch uncontrollably, fall over or briefly lose consciousness. When seizures keep coming back and no other clear cause is found, this is called epilepsy, but seizures can also be caused by poisoning, other illnesses or head injuries. A seizure can be life-threatening, so the dog needs a vet immediately.
- Arthritis Bones and joints Arthritis is inflammation of the joints in which the cartilage gradually wears down, leaving the joint stiff and painful. It can develop with age, after an injury or because of joints that did not form properly. Ongoing pain limits how freely and comfortably a dog moves, so changes are worth showing to a vet.
- Canine epileptoid cramping syndrome (Spike's disease) Nerves and muscles This is a condition in which a dog has episodes of muscle cramping: the muscles tighten involuntarily and walking becomes uncoordinated. Unlike in an epileptic seizure, the dog stays conscious throughout the episode. Because other illnesses can look similar, a vet decides whether this is the cause.
- Overheating (heat stroke) General health Overheating is a condition in which a dog's body temperature rises to a dangerous level because it can no longer cool itself down. Dogs barely sweat and cool themselves by panting, so heat in a closed car or exercise on a hot or humid day can overwhelm them quickly. Heat stroke damages the internal organs and is life-threatening, so the dog needs a vet immediately.
- Poisoning General health Poisoning happens when a dog swallows, breathes in or absorbs through its skin a substance that harms its body. Much of what is found in a home and garden is dangerous to a dog: rodent bait, antifreeze, chocolate, grapes and raisins, the sweetener xylitol, preparations meant for people. Even if the dog seems well, it needs a vet immediately.
Body systems: General health Hormones and metabolism Nerves and muscles Bones and joints