Side Effects of Phenobarbytol Used for Seizures in Dogs

Epilepsy is manageable in your dog.
George Doyle & Ciaran Griffin/Stockbyte/Getty Images

The diagnosis of epilepsy can be scary, leaving pet parents with many questions. Fortunately, this often hereditary neurological affliction can be managed with appropriate medication and monitoring. Phenobarbital is the most frequently prescribed drug to prevent these scary episodes and while it can significantly improve quality of life, knowing the risks is equally important.

Phenobarbital Side Effects

After ruling out trauma as a cause of seizures, a veterinarian will use observation and baseline blood work to diagnose epilepsy. If seizures are occurring at a rate of two or more per month, medication such as phenobarbital may be prescribed. Often, this medication and rechecked blood work -- to ensure constant therapeutic range -- will be a lifetime commitment. Initial side effects include mild sedation and trouble with coordination as well as increased thirst and appetite as your pet becomes acclimated to the drug. After approximately two weeks, blood work is repeated and provided the phenobarbital level is within the therapeutic range, your pet should begin returning to normal behavior. Blood work should be checked again at three months and then every six months. Of more serious consequence is potential liver or kidney damage as these organs process the drug. This can be monitored through routine blood work and your veterinarian can avoid prescribing contraindicated medications.