Seizures & Your Pet
by Linda Mar Veterinary Hospital
Definition
Seizures have specific characteristics according to if they are generalized or partial.
Generalized Seizures
There is whole body involvement with some or all of the following signs: loss of consciousness (the pet is unaware of its surroundings and doesn't respond to its name when called), loss of control of the legs (collapse or involuntary twitching or jerking of the legs), loss of control of the head (clamping motions of jaw), and loss of control of bladder and rectum (urination and/or defecation).
Partial seizures
There is partial body involvement with either involuntary head or leg movements or sometimes, abrupt behavioral changes. The seizure itself is often followed by a period of disorientation that may last a few minutes to several hours. Other episodes that can look like seizures are fainting spells associated with heart disease and/or arryhthmias or sleep disorders.
Causes
Causes of seizures can originate from the brain (intracranial) or outside the brain (extracranial).
Intracranial causes
- Epilepsy (recurring seizures in a young to middle aged dog or cat after other causes have been ruled out), trauma, migrating parasites, viral infections, bacterial infections, immune-mediated diseases, tumors
Extracranial causes
- Low blood sugar levels (hypoglycemia); common in small breed puppies, poorly regulated diabetic cats, and dogs with pancreatic tumors (insulinomas)
- Low calcium levels (hypocalcemia); can occur in small breed pregnant dogs or shortly after birthing, or hyperthyroid cats that recently have undergone surgery
- Toxicities with organ dysfunction: liver, kidney
- Ingested toxins: snail bait (metaldehyde), antifreeze (ethylene glycol), lead, insecticides, rodenticides (strychnine, bromethalin),
Diagnosis
Complete blood panel including chemistries can rule out most extracranial causes. If these are normal, the problem is most likely originating from the brain. The brain, unfortunately, is inaccessible to easily performed tests.
Other tests
Tests to assess brain function and structure are often invasive, costly, require special equipment and must be done under general anesthesia. These procedures include: CSF taps (sample of the cerebral spinal fluid) to evaluate for inflammation or infection; EEG (electroencephalogram) to assess brain wave activity; magnetic resonance imaging (MRI) and computed tomography (CT) scans are used to check for masses such as tumors, abscesses or other lesions.
Because of the difficulty involved with completely assessing the brain, the diagnosis of epilepsy is often based on normal blood results, an animal's age, breed, and a recurrent pattern of seizures. Depending on the frequency and/or intensity of the seizures, your veterinarian may recommend medical treatment to control them. While the goal of treatment is to abolish seizures completely, this may not be feasible. But often the frequency and intensity can be lessened to allow the pet to have a good quality of life. Treatment is usually life long.
Treatment
If seizures are associated with a specific cause (hypoglycemia, hypocalcemia), this is addressed.
If epilepsy is diagnosed, treatment options include:
Monitoring without treatment--If the seizures happen infrequently (1-6 times a year) and aren't long lasting, some owners opt for their animals "to live with it" rather than giving daily medication. Ideally, you should keep track of the frequency and duration of your animal's seizures, and your veterinarian should be contacted if the frequency, duration and/or intensity of the seizures increases.
Medications--Regardless of the type of medication chosen to control your pet's seizures, it is important you stay in close contact with your veterinarian with the goal of minimizing the seizures. These drugs can be used at a low doses initially, but increasing the dose and/or adding on other drugs may be necessary if seizures persist. Any changes in drug dosages and/or frequencies of administration should only be done on the advice of your veterinarian.
- Phenobarbital --This may be obtained from your veterinarian or through an outside pharmacy. It must be given 2 times daily; the dosage is adjusted according to if the seizures are controlled. This medication will cause increased thirst, increased urine output, hunger, and sometimes weight gain. Drowsiness is common when first starting the medication. Since it is metabolized by the liver, elevation in liver enzymes is common. Care must be taken when other drugs are given to a patient on phenobarbital, since negative drug - drug interactions can occur.
- Potassium Bromide -- This medication can be obtained only through some, but not all, outside pharmacies. It is given 1-2 times daily in the form of a compounded liquid or pill. The dosage and frequency is adjusted according to if the seizures are controlled. When given once daily, it is usually given in the evening. Since the liquid is bitter tasting, it is recommended to give it with food. This medication will occasionally cause drowsiness when first started.
- Valium (diazepam) -- This medication can be obtained through any outside pharmacy. This drug alone usually can not effectively manage seizure patients for long term control. Given as needed, it is useful for short term control of seizures when it is given immediately orally when a pet is recovering from a seizure. This is to prevent yet another seizure from occurring ("clustering"). A few dogs will have such intense seizures that they may necessitate administration of injectable valium (given rectally via syringe), given by the owners at home.
Management
If no seizures have occurred for a year or more, sometimes the drug doses are decreased. This should only be done after consulting with your veterinarian.
If seizures persist, the medication must be continued, and the dosage is often increased or combined with another medication. This should only be done after consulting with your veterinarian
Drug blood levels and panels and monitoring
Doing general blood panels, especially to evaluate liver enzymes while on phenobarbital treatment, and electrolytes when on potassium bromide treatment, are important in monitoring your pet's overall health. These are recommended at least yearly. These can be done at any time in relation to time of administration of the drugs.
Measurements of drug levels of phenobarbital and potassium bromide are usually done within 6-8 weeks of starting these medications. It is recommended to test levels yearly and following a change in dosing.
These are timed tests so that it is important when scheduling appointments for measurement of drug levels, it is correlated with when the medication was administered.
Phenobarbital levels are done within 10-12 hours post pilling and potassium bromide levels are checked just prior to the time when the pet normally receives the medication. There are no blood levels done to evaluate valium levels.
When your pet does have a seizure, stay calm and provide a quiet environment (dim the lights and avoid loud noises). Do not put your fingers in its mouth. Note the duration and intensity of the seizure and contact your veterinarian.
If you have questions regarding this disease and its treatment, do not hesitate to contact your veterinarian.
The above is general veterinary information. Do not begin any course of treatment without consulting your regular veterinarian. All animals should be examined at least once every 12 months.
About the Author
Linda Mar Veterinary Hospital and its cat-only affiliate, Coastal Cat Clinic, are small animal practices located in Pacifica, California. To find a veterinarian or to learn more about the vet clinic and our staff, visit:[http://lindamarvet.com/]
