What makes you have a seizure?


The brain consists of a network of nerve cells that are permanently active. Electric currents are directed back and forth between functional brain sections according to the respective functional processes. After an action has been carried out, the electrical command is interrupted or at least contained. There is a constant balance between the generation of excitation and the containment of an electrical current in the nerve cell network.

Sudden electrical discharges from many nerve cells without adequate control, which can occur in the brains of almost all animals, are the trigger for epileptic seizures. A seizure alone is not an epileptic disease that requires treatment. Only the recurring seizure activity needs to be taken seriously and further investigated.

What do epileptic seizures look like in dogs and cats?

The word epilepsy comes from the Greek and means "to be seized" or "to be overwhelmed". On the one hand, this describes the "rapture", a behavior of sensual absence, staring into the void and the unanswered speech. The animals can lose urine or start to salivate. The pupils are dilated and the eyes are wide open. These signs are an expression of a concentration of excitation in a delimitable part of the brain that controls attention and concentration and vegetative processes. The pupils are massively enlarged and the eyes are often torn wide. If the electrical excitation activates an area that is responsible for controlling muscle movements, individual muscles of the face or limbs may twitch. If the excitation spreads unchecked over the whole brain, a generalized seizure occurs. The entire body shows unrestrained muscle activity, which is either tonic, i.e. in tightly tensed muscle activity, or in rhythmic twitching of all limbs, the head and the facial muscles. The animals are not conscious and do not notice anything from their environment, from their seizure, or from their caregiver. As a rule, urine and feces are deposited and the animals salivate heavily. In the vast majority of cases, the brain is able to stop the seizure and the symptoms resolve on their own.

What happens before a seizure?

An epileptic seizure usually follows a certain dramaturgy. Before the nerve cells discharge so massively that an attack is triggered, normal brain function is disturbed, which is noticed by the animals concerned. The animals can be nervous, seek proximity to the owner, be anxious and change their habitual behavior. Episodes of absence may also show up.

What happens after a seizure?

After a seizure, the brain basically does what it would do with a faulty computer - switch it off and restart it. After a seizure, one or more hearing aids can be switched off. This manifests itself in disorientation, absence, even blindness and paralyzed limbs. Please make sure to give your dog or cat some time to recover after an attack. Many animals react aggressively, either during or after a seizure. Even the kindest animals can bite in such a situation - they are not themselves.

What is a "status epilepticus"?

A "status epilepticus" means seizure activity that does not stop by itself as usual. Without veterinary help, this is a life-threatening condition. The constant muscle contraction leads to an overload of the body. The waste products of the muscle metabolism can damage the kidney. A massive discharge of adrenaline initially increases blood pressure, leading to increased cardiac activity, which can ultimately lead to cardiac arrest. The brain itself is also permanently damaged in a status epilepticus, which in turn favors the development of new seizures.

Which diseases should be confused with an epileptic seizure?

Heart disease can mean that the brain does not get enough oxygen at times. This effect is known from dizziness after sitting in a crouch for a long time and suddenly getting up quickly. Here the blood suddenly sinks into these legs and is not in sufficient quantities in the brain. Such a "syncope" can lead to a loss of consciousness. During the recovery phase, the animals can row and kick with their limbs because they want to get up again but are not recovered enough to be able to do so. An important difference to an epileptic seizure is the lack of slow recovery after a seizure. After a heart attack, the animals are usually back to normal very quickly. Saliva, urine and feces are also not observed. Syncope often occurs after stress on the circulatory system, while epileptic seizures occur more often during rest and not infrequently during sleep.

Epilepsy-like movements with falling, rowing the limbs and vocalizations are also observed in an attack of dizziness (acute vestibular syndrome). Here there is a malfunction of the organ of equilibrium. The animals fall down and can only get up again with outside help. This attack often lasts for a long time. The animals tilt their heads and twitch their eyes, which is an important distinguishing feature.

Your animal neurologist will ask about these symptoms.

How to diagnose epilepsy in dogs and cats

Unfortunately, there is no test to prove epilepsy, but you have to rule out the possible causes that can trigger a seizure step by step. It is important to understand that although epileptic seizures occur in the brain, the actual triggering cause does not have to be in the brain.

Causes of Epileptic Seizures

An epileptic seizure occurs when the balance between electrical excitation and the containment of that excitation is shifted. This imbalance can be caused by something inside or outside the brain. Internal causes lie in diseases of other organs of the body, which lead to metabolic disorders in the animals. Liver diseases and vascular malformations of the liver (so-called portosystemic shunt) can flood the brain with endogenous toxins (ammonia) that would otherwise be broken down in the liver. This ammonia significantly disrupts brain function.

Rapid drop in blood sugar levels can be caused by tumorous changes in the pancreas (insulinoma).

Deviations in the blood level from body salts such as calcium and potassium, which occur in kidney or adrenal diseases, as well as in diseases of the parathyroid gland, can also lead to seizures. These causes, and many more, lead to what is known as secondary epilepsy, a form that is not primarily due to a brain disease.

Poisoning as a cause of seizures in dogs and cats

Our pets' immediate environment is rich in toxins that can disturb the balance of nerve function and trigger seizures. From toothpaste and chewing gum to antifreeze, to pesticides in fields, or in slug pellets and insecticides from your own garden can cause seizures. In the case of seizures caused by intoxication, one speaks of reactive epilepsy.

A list of poisons can be found here: under construction

Structural brain diseases as a cause of epileptic seizures

Changes in the normal structure of the brain and its functional components can cause epileptic seizures. Depending on the age of the animals, different brain changes come into question. Young animals often have a deformity of the brain. Virus infections and other bacterial or parasitic pathogens can affect the brain. Young adult animals can develop inflammation of the brain, which occurs without an infection as a result of overreactions of the immune system (immune-mediated encephalitis). Severe traumatic brain injury can leave brain injuries and “scars” in the brain tissue.

Bleeding and cerebral infarction cause seizures in older animals. The most important cause in animals of advanced age is brain tumors.

Rare triggers of epileptic seizures

Rare, usually congenital metabolic disorders of the brain cells can lead to the degeneration of neurons. These are often tied to specific races.

Idiopathic epilepsy in dogs and cats

If all causes of secondary or reactive epilepsy are excluded, the diagnosis “primary” or “idiopathic epilepsy” is made. This assumes damage to individual nerve cells that do not react to the normal signals of a containment of electrical activity, or are independently active and independently trigger and spread electrical impulses. In some breeds of dogs, this form of epilepsy can be inherited.

Diagnosis of epileptic disease

First step of clarification: Medical history (anamnesis)

An intensive discussion must clarify how the epileptic seizures are clinically presented, at what intervals they occur, and how long they last. Triggering factors in the past or the present must be systematically explored. Last but not least, it must be certain that it is actually an epileptic attack and not a disturbance of the balance - the heart activity. Or another illness is present. Videos of the episodes are of great help here.

Second step of the investigation: the neurological examination.

If the triggering factor for epilepsy lies in the brain itself, the function of other systems of the nervous system is often damaged. Vision, eye movement, gait, or the reflexes of the head senses can be restricted and thus be a first indication of a functional or structural change in the brain.

Third step of the investigation: blood tests

A blood test can provide the most important information about organ damage and other disorders of the body's metabolism. In addition to the standard tests, the function of the liver (ammonia test) must be checked from a blood sample immediately after collection. If there is any indication of deviations from the normal values, an ultrasound examination of the liver blood vessels is indicated.

Investigations for infectious agents in the blood can provide an indication of an infection, whether these are actually involved in a brain infection must be further clarified.

Fourth step of the investigation: Magnetic resonance tomography (MRI) of the head

The imaging examination of the brain enables the representation of malformations, tumors, bleeding and infarctions, as well as most of the inflammations that can affect brain function.

In various examination sequences, changes in the brain can be reliably detected and characterized more precisely, piece by piece. General anesthesia is required for this examination.

How is epilepsy treated?

In secondary epilepsy, the underlying cause must be eliminated. If a brain tumor is removed, epilepsy usually no longer occurs. If your animal has primary epilepsy, drugs must dampen the electrical activity in the brain. THESE MUST BE TAKEN FOR LIFE AND MAY NOT BE DISCONNECTED BY YOURSELF! Your specialist animal neurologist will provide you with information on precise anti-epileptic medication therapy that is tailored to your animal.

Can you treat epilepsy with alternative healing methods?

Epilepsy is not one of the indications for alternative therapy.

What can I do if my animal does not respond to medication or if it loses its effect?

As with humans, the goal of anti-epileptic therapy is to ensure that your animal does not have seizures more than once a month. Although complete freedom from seizures always occurs again, this is not the goal of therapy.

Around 75% of the animals respond excellently to an anti-epileptic drug and can lead a relatively unrestricted, normal life. Of the remaining 25%, around 75% can be easily adjusted with a second drug.

A small percentage of the animals may become resistant to therapy at the beginning or during the course of treatment. That means, despite optimal therapy, the animal has many seizures. This condition is a challenge for your veterinarian and requires unconventional therapy strategies.

For further reading

The book “Die idiopathische Epilepsie des Hundes” from Enke Verlag is recommended to interested pet owners. A book for veterinarians that contains a lot of understandable information for pet owners.