{"id":631911,"date":"2025-04-10T18:49:11","date_gmt":"2025-04-10T22:49:11","guid":{"rendered":"https:\/\/www.singlecare.com\/blog\/?p=631911"},"modified":"2025-10-06T15:31:15","modified_gmt":"2025-10-06T19:31:15","slug":"side-effects-of-phenobarbital-in-dogs","status":"publish","type":"post","link":"https:\/\/www.singlecare.com\/blog\/side-effects-of-phenobarbital-in-dogs\/","title":{"rendered":"What are the side effects of phenobarbital in dogs?"},"content":{"rendered":"

Phenobarbital<\/span><\/a> (brand name Luminal) is a barbiturate used in veterinary medicine to control or prevent seizures. Also known as an anticonvulsant, phenobarbital works as a central nervous system depressant, increasing an animal\u2019s seizure threshold to lessen the likelihood and severity of seizures. Dogs taking phenobarbital may experience mild short-term side effects or more serious long-term side effects, which is why regular blood testing is crucial to monitor liver enzyme function and blood counts.<\/span><\/p>\n

What is phenobarbital used for in dogs?<\/span><\/h2>\n

Anticonvulsant medications are used to treat seizures in humans and canines. One of the most commonly used anticonvulsant medications (also known as antiepileptic drugs) used by veterinarians is phenobarbital, a barbiturate. Barbiturates are depressant drugs chemically derived from barbituric acid and have been approved by the FDA to control seizures in dogs.<\/span><\/p>\n

Barbiturates work by <\/span>increasing gamma-aminobutyric acid (GABA)<\/span><\/a> in the brain, slowing brain cell activity, and calming and reducing seizure activity. Phenobarbital is most commonly administered to dogs orally via phenobarbital tablets or intravenously, but it can also be made into a topical gel at a compounding pharmacy and applied on the skin.<\/span><\/p>\n

A veterinarian will prescribe phenobarbital to your dog if they are experiencing seizures or epilepsy to reduce both the frequency and severity of seizures.<\/span><\/p>\n

The dosage of phenobarbital used depends on your dog\u2019s condition. For severe situations, a higher dose is immediately administered. \u201cHigh-dose phenobarbital is used mainly when you are loading a patient,\u201d says Jason Horgan, DVM of <\/span>LeadER Animal Specialty Hospital<\/span><\/a> of <\/span>South Florida<\/span>. When loading a patient, a veterinarian aims to rapidly achieve therapeutic levels of the drug in the dog\u2019s bloodstream to quickly stop the simultaneous ongoing seizure activity. Once these therapeutic levels have been achieved, lower maintenance doses on an ongoing basis become the standard to maintain proper treatment levels.<\/span><\/p>\n

Nita Vasudevan, DVM, a veterinarian of <\/span>Embrace Pet Insurance<\/span><\/a> in Orlando, Florida, states that phenobarbital can also be used alongside other drugs for specialized treatment. \u201cLow doses of this medication are used for the management of pets who have rare or inconsistent seizures [and sometimes a low dose is used] along with a combination of anti-seizure medications to obtain adequate seizure control,\u201d she says. \u201cHigh doses are used in pets who have more severe or cluster seizures, or some pets who are still refractory, even with a combination of seizure medications.\u201d<\/span><\/p>\n

Your veterinarian can provide guidance on the best dosing procedure for your pet to control seizure activity effectively.<\/span><\/p>\n

What are the side effects of phenobarbital in dogs?<\/span><\/h2>\n

While it is crucial to get your pet\u2019s seizures under control, phenobarbital can have a variety of short-term side effects for dogs. According to veterinary experts, common side effects of phenobarbital may include:<\/span><\/p>\n