The term convulsions refers to involuntary, sudden, jerky muscle contractions involving a set of muscles or the entire body. We will tell you about convulsions in dogs.
Classically we speak of “convulsive seizures”. Not every seizure is synonymous with “epilepsy”. It is also important to differentiate seizure and syncope.
Seizures are triggered when there is too much electrical activity in the brain; in fact, the brain contains many cells, called “neurons” which have basic electrical activity that can be evaluated and measured (especially in humans) by carrying out an electroencephalogram (ECG). This electrical activity generally controls by the body through the intermediary of numerous brain messengers called “neurotransmitters”: some are excitatory, others are inhibitory. It is a rupture of this electrical balance which will be at the origin of an increase in cerebral electrical activity and the triggering of convulsive seizures.
When an electrical focus triggers at a site in the brain, two things can happen:
- a spread of electrical activity “step by step” that can be called, very pictorially, a “brush fire” effect
- a propagation of the electrical activity at a distance, concerning a group of neurons of the other cerebral hemisphere (“mirror” effect) because of “link neurons” (kind of electrical connection wires).
Causes of seizures in dogs
We will distinguish 3 major families of pathologies that can lead to convulsive seizures:
- lesional intracranial causes: we note the presence of a lesion in the brain, that is to say an anomaly of structure, of conformation of the brain tissue. It can be head trauma, birth defects (hydrocephalus for example), tumor, inflammation (encephalitis secondary to infection or not), cerebrovascular accidents (blocked or ruptured cerebral blood vessels causing hemorrhage ), …
- extra-cranial causes: in these cases, we note the presence of a general blood disorder which secondarily disrupts cerebral functioning. It may be hypoglycemia in lactating bitch, intoxication, heart disease (differentiate from syncope) or respiratory disease, advanced liver or kidney disease, etc.
- l’épilepsie primaire (encore appelée épilepsie essentielle ou idiopathique) : dans ce cas, les animaux présentent des crises convulsives mais n’ont aucune lésion cérébrale ni aucune maladie générale extra-crânienne.
Symptômes
En fonction du nombre, de la localisation et de la vitesse de propagation des foyers électriques qui se déclenchent de façon anarchique dans le cerveau, les symptômes seront plus ou moins marqués.
There may be generalized “tonic-clonic” seizures with loss of consciousness, rolled up eyes, pedaling, muscle contractions of the whole body, salivation, urination, defecation, vocalizations (screaming, barking). This type of seizure is quite rapid (a few seconds to a few minutes in general) and the animal comes back to itself over several minutes or several hours (after the seizure, it may have difficulty moving and recognizing its environment; it may also sometimes start to drink or eat heavily).
In other cases, the convulsive seizure can be more discreet, partial, with, for example, just salivation, the isolated contraction of a single group of muscles (limbs, face) or even hallucinations (animal that “gobbles”). »Invisible flies,…).
And, in some cases, the crisis can isolate. In others, the crises can follow one another and succeed one another at short intervals of time.
It is rare that an animal dies during a seizure: this can nevertheless happen if the seizures are repeated in an anarchic way.
Diagnostic
Depending on the clinical suspicion, various additional examinations may be considered.
Before any additional examination, you will discuss with your veterinarian the evolution of the symptoms. And you will also discuss the medical file of your animal (age, breed, pathological history, current medications, lifestyle, etc). It is also essential to carry out a general clinical examination of the animal as well as a neurological examination in order to better target the additional examinations to carry out:
- A medical scan of the brain using a CT scan or magnetic resonance imaging (MRI) to assess brain damage (this test is often combined with a puncture of cerebrospinal fluid).
- Various blood tests to explore extra-cranial causes.
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Treatment of seizures in dogs
The treatment is, of course, dependent on the origin of the seizures.
If a cause has been identified, it is important to take care of it (if possible) with specific treatment. For this purpose, your veterinarian may resort to medical treatments (antibiotics, anti-inflammatory drugs, corticosteroids, chemotherapy). Surgical, radiotherapy or a combination of these three types of treatment.
In essential epilepsy or lesional intracranial diseases, the use of anti-epileptic treatments is sometimes essential to manage convulsive seizures. Several molecules are, to date, accessible in veterinary medicine, with their advantages and disadvantages. It is recommended, in first intention to use only one molecule. Your veterinarian will choose the one most suited to the pathology highlighted; clinical and blood checks are essential to adjust drug doses. The treatment is sometimes to administer for life.
If the convulsions in your dog start at your home, it is essential to check that the animal is “safe”. The animal should not near a staircase, a balcony, etc. It is important to leave him calm, without stimulating him: you can possibly talk to him to calm him down. It, however, formally contraindicates to put your fingers in its mouth to stick out its tongue. And, it will not swallow it but it may, on the other hand, involuntarily bite you in a violent way. In some cases, when the seizures follow one another, your veterinarian may prescribe an anti-convulsant medication to be administered into the anus in the event of a seizure. In all cases, the onset of a convulsive crisis warrants a consultation with a veterinarian.
Sometimes it can interesting to film the seizure with a camcorder or smartphone. It can help your vet to make a diagnosis if, when you bring your pet to the vet clinic. And, the seizure is over.
Prognosis
The prognosis also depends on the cause of the seizures.
It is, in general, good when essential epilepsy will diagnoses, treats and controls quickly: the animal can live quite normally. In some cases, it is possible to wean the animal off anti-epileptic drugs. This should only be done under veterinary advice.
In other cases, the prognosis is much darker. The cause may be incurable (malformations, tumor, etc.) or the response to anti-convulsant treatment ineffective despite the combination of several drugs.
Conclusion
The evidence of convulsions should take seriously in dogs. It is important to take into account epidemiological (age, race, etc.). And clinical criteria in order to offer suitable additional examinations to determine the cause of these convulsive attacks. Seizures are not always synonymous with epilepsy. It is important to quickly manage these convulsive seizures in order to prevent them from growing in importance. Your veterinarian will offer you the appropriate care for your animal.