Phenobarbital for Dogs

Phenobarbital for dogs is a medication that is recommended for canines with frequent seizures or idiopathic epilepsy. Phenobarbital is used in humans and has been created for humans. The medication hasn’t received FDA clearance for use in dogs, but may be prescribed by vets.

Phenobarbital and Dog Seizures

Phenobarbital is a medication that is used for dog seizures. The medication is also known as Pb or Phb.

Dog seizures may be experienced due to epilepsy, poisoning, heat strokes or other severe health conditions. The seizures may have a trigger in the dog’s environment (i.e. thunders or other loud noises) but may also occur due to a chemical imbalance in the dog’s body.

Phenobarbital is a medication that can be prescribed if the seizures occur at a frequent rate (i.e. more often than once per month). If the dog has an isolated seizure, the medication shouldn’t be administered, as it may have side effects that can be more serious than an occasional seizure.

Phenobarbital may also be prescribed if the dog has less frequent seizures which last for over 5 minutes.

Phenobarbital Effects

The medication may prevent the occurrence of the seizures but may also stop an ongoing seizure.

Typically, it takes up to 14 days for the medication to be fully effective, so during the first 2 weeks of treatment, Phenobarbital cannot be reliable in preventing seizures. Also, if Phenobarbital is administered to stop an ongoing seizure, it may not be 100% effective.

The treatment with Phenobarbital may be effective in over 60% of dogs with idiopathic epilepsy or frequent seizure episodes.

Phenobarbital Side Effects 

Phenobarbital reduces the activity of neurons and nervous system.

The lengthy administration of Phenobarbital may lead to a few side effects that include:

  • Lethargy
  • Sleepiness
  • Vomiting
  • Diarrhea
  • Lack of coordination
  • Increased appetite and thirst
  • Delayed response when called
  • Irritability
  • Excessive urination
  • Liver damage

Some of these side effects may only be present during the first months of treatment, while others (i.e. increased appetite and excessive urination) are long term side effects that will disappear only if the treatment is discontinued.

Liver damage is the most severe side effect of Phenobarbital and may occur if the medication is used for over 3 months.

Phenobarbital Dosage 

Phenobarbital can be administered as tablets or in liquid form, as drops. The dosage will depend on the size of the dog, his metabolism rate, the severity of the seizures and frequency of seizure episodes.

The vet will prescribe a low dose of Phenobarbital (i.e. 2 mg per body weight twice per day) first and monitor the dog’s evolution. If seizures occur, the dosage will be increased. If no seizures occur within a timeframe of 1 month, the dosage will be maintained at the same level.

You should never administer Phenobarbital without consulting the vet first. In any case, Phenobarbital requires prescription for humans as well, so you will need to get a prescription from your vet.