Why do Chihuahuas shake? Common causes and when to see a vet

Chihuahuas are known for trembling, and owners often wonder whether it is normal. Most of the time there is a simple explanation. Sometimes, though, shaking is a sign that a dog is unwell or in pain, so it helps to know the difference.

Common, everyday reasons Chihuahuas shake

They are cold

The Royal Kennel Club's breed standard gives a Chihuahua's weight as up to 2.7 kg (6 lb). A body that small loses heat quickly, especially in smooth-coated dogs, so many Chihuahuas shiver in weather that larger dogs barely notice. A warm bed away from draughts, and a well-fitting dog coat for winter walks, often stops the shivering.

They are excited

Some Chihuahuas tremble when they are happy and expecting something good, like a walk, a meal or a family member coming home. This kind of shaking stops when they calm down.

They are anxious or frightened

Fear and worry are common causes of shaking. Loud noises such as fireworks, unfamiliar people or dogs, car journeys and vet visits can all set it off. Other signs of anxiety include a tucked tail, ears pulled back, lip licking, yawning, trying to hide and avoiding eye contact.

They have learned it gets attention

If shaking has often been followed by a cuddle or a treat, some dogs may shake more around people. Only assume this once you have ruled out cold, fear, pain and illness.

When shaking can mean illness or pain

Shaking can also be a sign of a health problem. Contact a vet if the shaking is new, doesn't stop, or comes with other signs. Possible causes include:

• Pain, for example from a sore back or joints, dental disease or an injury. Dogs in pain may also be reluctant to move, hide, or cry when touched.
• Low blood sugar (hypoglycaemia), especially in very small or young puppies that have missed meals. Signs can include weakness, wobbliness and sleepiness.
• Poisoning, for example from chocolate, xylitol (a sweetener found in some sugar-free foods), certain human medicines, or slug and rodent baits.
• Nausea or a stomach upset, often with drooling, lip licking, vomiting or diarrhoea.
• Fever or infection.
• Neurological problems, including seizures. A seizure may involve stiffness, paddling legs, drooling, loss of awareness or loss of bladder control.
• Ageing. Some older dogs develop trembling in the back legs, which can be linked to weakness or joint pain.

Call a vet straight away if your dog:

• may have eaten something poisonous;
• is weak, wobbly, collapses or has a seizure;
• is shaking and vomiting, has diarrhoea, or won't eat;
• seems to be in pain;
• is a young puppy that is shaking and seems weak or very sleepy.

If it is out of hours, call your vet's emergency number. Don't give human painkillers or other medicines unless a vet tells you to: some are toxic to dogs.

How to help a shaking Chihuahua

1. Check for an obvious cause. Are they cold, excited, or reacting to something frightening?
2. Warm them up with a blanket, a cosy bed out of draughts, or a coat outdoors.
3. Comfort a worried dog calmly, and move away from whatever is scaring them if you can. Comforting a frightened dog doesn't reward the fear.
4. Never punish shaking. Telling a dog off makes fear worse and can hide signs of pain.
5. Build confidence gradually with gentle, positive introductions to new people, places and sounds, and reward-based training.
6. Keep a note of when the shaking happens and how long it lasts. A short video can be very helpful for your vet.

If anxiety is causing frequent shaking, talk to your vet first to rule out pain or illness. They can refer you to a qualified behaviourist if needed.