What this means
During a seizure a dog may collapse, jerk its legs, clench its jaws, drool heavily and pass urine or stool without meaning to. It is not aware of what is happening and does not respond to its name. Before a seizure some dogs seem restless, hide or cling to their owner, and afterwards they are dazed, unsteady, may be briefly unable to see or may walk in circles.
It is important not to put a hand near the dog's mouth, because it may bite without meaning to, and to clear objects around it that it could hurt itself on. If you can, note when the seizure began and how long it lasted, as these details matter a great deal to a vet. If it is safe, film it: a video helps tell a seizure from other conditions.
There are many causes. Some arise in the brain, while others are a problem of the whole body, for example low blood sugar or a liver disorder that lets substances build up in the blood and affect the brain. Certain breeds have a tendency to inherited forms of seizure. The cause can only be found by a vet, often after tests.
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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Epilepsy
A long-term brain disorder that causes repeated seizures with no other clear cause. The first seizures often appear in young or middle-aged dogs.
About the condition: Epilepsy and seizures -
Low blood sugar
When the blood lacks sugar, the brain does not get its energy, so a dog may stagger, tremble or seize. Small puppies and dogs of small breeds are especially vulnerable.
About the condition: Hypoglycemia (low blood sugar) -
A blood vessel abnormality of the liver
When blood bypasses the liver, substances that affect the brain build up in it. The dog may seem dazed or stunted in growth, and seizures sometimes follow a meal.
About the condition: Liver shunt (portosystemic shunt) -
Fluid build-up in the brain
Too much fluid in the cavities of the brain presses on it. It is seen more often in small-breed puppies with a domed skull.
About the condition: Hydrocephalus -
An inherited nerve cell disease
A rare inherited disorder of brain cells that gradually changes a dog's behaviour and movement. Poor coordination or vision is seen along with seizures.
About the condition: Neuronal ceroid lipofuscinosis
What else to watch for
These observations help your vet build the picture faster. Note down what you saw and when.
- When the seizure began, how long it lasted and how your dog acted before and after
- Whether there was loss of awareness, drooling or passing urine
- Whether seizures repeat and how often
- Whether your dog could have swallowed a poison or had a blow to the head
- Whether your dog staggers, cannot see or walks in circles afterwards
- Whether your dog recovers to its usual self
When to book a routine visit
Even if the seizure passed quickly and your dog seems normal, contact a vet the same or the next day, especially if it is a first seizure or they are repeating. If a seizure goes on, repeats without a break or your dog does not recover, go straight away.
Related conditions
Conditions whose entries mention this sign. The list is somewhere to read on, not a way to reach a diagnosis.
- 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.
- 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.
- Liver shunt (portosystemic shunt) Digestion and liver A liver shunt is an abnormal blood vessel that carries blood from the intestines around the liver instead of through it. As a result, the liver cannot clear the toxic substances coming from the gut, and they enter the general circulation, affecting the brain and the whole body. A shunt can be present from birth or develop later because of other liver disease.
- Hydrocephalus Nerves and muscles Hydrocephalus is a condition in which too much cerebrospinal fluid builds up in and around the brain and presses on the brain tissue. It can be present from birth and show up in puppies, or develop later when inflammation, an injury or a tumour blocks the fluid from draining. The pressure on the brain can affect a dog's behaviour, movement, sight and ability to learn.
- Neuronal ceroid lipofuscinosis Nerves and muscles This is a group of inherited diseases in which cells cannot break down certain waste substances, so these build up in the nerve cells of the brain and eyes and gradually damage them. The disease is progressive, so over time changes in the dog's behaviour, sight and movement become more marked. Genetic tests exist for some of its forms.
- 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: Nerves and muscles Hormones and metabolism Digestion and liver General health