Definition and classification of epilepsy in dogs and cats: basic physiological knowledge of epilepsy (absolutely understandable series) IVETF definition of epilepsy; seizure, epileptic seizure, reactive seizure, epilepsy, persistent epilepsy, cluster epilepsy; IVETF of epilepsy Classification: focal epilepsy and generalized epilepsy; idiopathic epilepsy and structural epilepsy.

Diagnosis of epilepsy in dogs and cats: The importance of medical history investigation: Diagnosis process: Like vomiting, epileptic seizures are only symptoms! The most common causes of reactive seizures and the tests that may be needed; investigation of structural epilepsy; diagnostic criteria for idiopathic epilepsy.

Diagnosis: blood routine, biochemistry, coagulopathy combination Examination and urinalysis should be performed in epileptic animals. Suspected liver disease can be assessed through clinical phenomena, symptoms, or biochemical indicators (eg, hypoalbuminemia, low cholesterol, low urea nitrogen, hypoglycemia, abnormal liver enzymes), bile acid or free ammonia levels to assess whether liver problems are causing epilepsy. . If the animal is receiving antiepileptic drugs, serum drug levels of AEDs should be measured more than is necessary for diazepam.

Blood pressure testing and blood oxygen testing are encouraged, especially if you have recently experienced severe epilepsy or respiratory distress. Imaging and cerebrospinal fluid examination are also recommended in animals with no cause of epilepsy, unless the animal has obvious metabolic problems or epilepsy caused by toxicants. MRI is the imaging modality of choice, but CT is also useful diagnostically. Many forebrain injuries are visible on CT, even if there are only minimal changes. If there is no evidence of increased intracranial pressure (eg, severe midline metastasis, pituitary prolapse, infarcted hydrocephalus) or intermediate tumor lesions on imaging, CSF collection can be performed.

Pathological findings: Physical examination and histopathology rarely reveal the cause of epilepsy. Prolonged epilepsy of any cause, regardless of the cause, can lead to edema and neuronal necrosis, especially in the hippocampus and temporal lobes.

Treatment: The first goal of treatment is to prevent epileptic seizures and prevent future epileptic seizures. The condition of the sick animal should be observed after the administration of each rapid antiepileptic drug. If serum biochemistry reveals an underlying metabolic problem such as hypoglycemia or hypocalcemia, correct it immediately. If the sick animal has sustained convulsions or has at least two convulsions within 24 hours, the dose of anti-epileptic drugs should be increased. If the cause of epilepsy is caused by poisoning or metabolic disease, the dose should be gradually reduced after a few weeks to maintain anti-epileptic drugs. Animals with intracranial structural abnormalities, idiopathic epilepsy, or unresolved metabolic disease require continued maintenance doses of antiepileptic drugs unless the underlying cause is determined to be resolved.

Selection of drugs:

Emergency: If the sick animal is in a state of epilepsy, if the animal is not using anti-epileptic drugs, intravenously inject 0.5mg/kg diazepam, if the animal is using p450 inducer For example, phenobarbital, the dosage of diazepam is 1mg/kg. In order to avoid being unable to find a vein to give the drug immediately, the drug is sometimes administered rectally, but the dose is twice that of the intravenous drug. Midazolam may be chosen instead of diazepam. Dogs with slow or partial responses to diazepam can be controlled with anti-epileptic drugs. Besides diazepam, phenobarbital is the next option and can be given intravenously. Propofol or other fast-acting antiepileptic drugs can be used first when phenobarbital has not yet taken effect. Recently, new anti-epileptic drugs like levetiracetam can be administered intravenously and are a safe choice for dogs and cats.

The following is a short list of some first aid medications.

Stabilizing mechanism: GABA receptor agonist (liver metabolism). Side Effects: Sedation, excitement, liver disease (occurring in cats after oral administration). Dosage 0.5ml/kg (1mg/kg when phenobarbital is used) intravenously administered as one dose; CRI 0.2~2mg/kg/h (classic initial dose 0.2~0.5/kg/h); refers Intestinal (double for intravenous injection). When the animal's ion imbalance has not been corrected, diazepam CRI and injection must be used to maintain the body's sedation and prevent the next occurrence of epilepsy. The continuous intravenous infusion of diazepam is the last thing that needs to be stopped.

Midazolam, mechanism: GABA receptor agonist (hepatic metabolism). Dosage: 0.1~0.3mg/kg, IV, IM, SQ.

Phenobarbital, mechanism: GABA receptor agonist half-life (hepatic metabolism) of 24 to 72 hours. Side Effects: Polyuria, polydipsia, polyphagia, behavioral changes, liver disease (especially at blood levels >35-40 mcg/mL), bone marrow cachexia (usually present within 1 month of initial treatment), skin Disease, mobility impairment, low thyroid hormone. Cardiovascular depression and hypotension may occur if doses are given intravenously. Dosage: Start with 12 to 16 mg/kg. After administration of remaining drug for more than 24 hours, give a single intravenous dose of 6 mg/kg in relatively stable animals. It takes 20 minutes for the medication to be most effective, so other medications may be needed to control the epilepsy while the seizure is occurring. If you encounter intractable epilepsy, the maximum daily dose is 30mg/kg/d, but only 16mg/kg can be used each time.

Other drug options, propofol mechanism: short Potent anesthetic (hepatic and systemic particulate metabolism). Side Effects: Sedation, cardiorespiratory depression, hypotension, formation of Heinz bodies (continuous in cats). Dosage: 2 to 8 mg/kg in one dose; CRI 0.1 to 0.6 mg/kg/min.

For pentobarbital, use 1 to 3 mg/kg in one dose, followed by repeated doses or 3 to 10 mg/kg/h CRI. Although pentobarbital can reduce the severity of convulsions, some authors remain skeptical of its ability to suppress the activity of neurons involved in epilepsy.

Pentobarbital is not recommended by the author in this chapter.

As an alternative, levetiracetam is an effective antiepileptic drug and can be given intravenously. Anesthesia can be induced and maintained with isoflurane or with a continuous intravenous infusion of propofol or phenobarbital. These animals require intubation and assisted breathing.

Maintenance therapy: Antiepileptic drugs in veterinary medicine are evolving rapidly. While many veterinarians would consider traditional medications like phenobarbital and potassium bromide as first-choice medications, other authors would prefer newer, more expensive medications that have fewer side effects, do not require very strict monitoring, and are more effective than traditional medications. Or the same. Potassium bromide can cause unwanted lung infections in cats and is not recommended for use in cats. Diazepam is used as a maintenance anti-epileptic drug in cats, but many authors do not recommend it because it has been reported that diazepam may cause severe and irreversible liver disease in cats. In some animals, the disease cannot be controlled with one anti-epileptic drug. In this case, a combination of two or even three types of anti-epileptic drugs may be used. When using traditional medicines for treatment, be sure to make sure that the blood drug level is within the appropriate range before increasing the dosage.

Many new drugs are administered orally. New drug, zonisamide (Zonegram)

Mechanism: blocks calcium and sodium ion channels; enhances the release of GABA. The half-life is 15 hours. Hepatic metabolism. Side effects: ataxia, vomiting, lethargy and dry eye. Follow-up monitoring: CBC and biochemistry every six months. Blood levels of zonisamide are not commonly used. Dosage: 4 to 10 mg/kg PO twice daily for dogs. If other drugs that induce hepatic microparticle enzymes are already being used, the maximum dose of the drug should be used. Not recommended for use on cats.

Levetiracetam (Keppra) mechanism: calcium ion and glycine channel blocker. The elimination half-life in dogs is 4 hours, but the most effective effects occur at low plasma concentrations. Extrahepatic hydrolysis and urinary excretion. Side Effects: Very safe.

Ataxia, drooling, and gastrointestinal symptoms may occur at very high doses. Follow-up: CBC and biochemistry every 6 months. Dosage: The initial dosage for dogs is 20 mg/kg PO 3 times a day. Later, the dosage can be increased by 10 to 20 mg/kg. It can be injected slowly intravenously at 20mg/kg.

Similar dosages in cats. Gabapentin (Neurontin) mechanism: Increases the level of synthesized GABA and blocks calcium ion channels. Renal (major pathway) and hepatic metabolism. The elimination half-life in dogs is 3 to 4 hours, although significant effects occur at low peak drug concentrations. Side effects: Mild ataxia and sedation. Follow-up: Gabapentin levels are not widely available and the effect in humans is not clear. Dosage: 30 to 60mg/kg/d, given to dogs in three to four divided doses. Give 5 to 10 mg/kg PO 2 to 3 times daily to cats. Do not use liquid plus barpentin because of the presence of xylitol.

Traditional drug, phenobarbital: Follow-up: Blood levels need to be monitored for 14 to 21 days after dose changes or if epilepsy control is poor. In dogs, biochemical, CBC, and bile acid tests are recommended after starting medication. It is recommended to retest biochemistry every 6 months, plus barpentine levels and bile acid quality. Dosage: In dogs a starting dose of 2 to 3 mg/kg twice daily is achieved when efficacy is controlled. When the control effect is poor, gradually increase the amount. Therapeutic level blood concentrations are generally 15 mcg/ml to 35 mcg/ml in most dogs and 15 to 30 mcg/ml in most cats.

Potassium bromide, mechanism: GABA receptor agonist, half-life is 20 to 30 elimination half-life (renal metabolism). Side Effects: Polyuria, polydipsia, polyphagia, gastrointestinal disorders, behavioral changes, pancreatitis, skin disorders, ataxia (especially hind limbs) and incorrect assessment of chloride concentrations in blood biochemistry. It is contraindicated in cats because it may cause fatal pneumonia in cats; it is also contraindicated in animals with kidney disease and heart disease. Follow-up: Blood concentration should be measured 3 months after initial administration or change of dosage. Every 6 months to 1 year, biochemistry, urine routine and blood bromide concentration should be tested. Try not to change the type of food if possible, because salt concentration can change the concentration of drugs in the blood. Dosage: Young animals should be dosed at 100 mg/kg per day for 5 consecutive days. In emergency situations, the total dose may exceed the daily dose and may be administered rectally, but gastrointestinal symptoms may be frequent. Maintenance dose is 30 to 40 mg/kg PO daily. When the dose is increased, partial dosing (100 mg/kg and new dose/day for 5 consecutive days) is recommended. Diuresis with 0.9% NaCl will quickly reduce blood concentration. Treatment drug concentration levels range from 1 to 3 mg/ml.

Prevention/Interaction: AEDs are compound drugs, so any preventions and effects listed are only a few of the possible problems. In general, it remains to be seen whether acepromazine causes epilepsy, but some practitioners believe that caution should be exercised when using it in dogs with epileptic problems. Any drug that lowers the seizure threshold should be avoided. The dose of any drug metabolized by the hepatic cytochrome p450 pathway required to be administered with phenobarbital should be changed or increased.