My puppy might have taken phenobarbital. What signs to look for?

Unfortunately you do not mention the weight of the dog which received the phenobarbital. A normal dose would be 2-3 mg of phenobarbital per kg (2.2 lbs) of dog. If your dog is much smaller than 6 kg (13lbs) then you need to watch it closely for the next few hours. Your dog will most likely get very sleepy. If it sleeps so deep you cannot wake it up or if you think it is not breathing properly, you will need to take it to the emergency room. If the ingestion occurred within the last hour and the amount ingested was a significant overdose, you should consider taking your dog to the emergency vet so that vomiting can be induced to get the drug out of the system. Also if your dog has liver disease, please take it to the emergency clinic.

Thank you for reaching out to Pet Coach. This should not be of major concern but may cause some mild sedation in your dog that ingested that dose unnecessarily. If your dog is on medications as well, phenobarbitol may or may not be OK to combined with those medications so that is something else to consider. As well as dogs that have decrease in liver function may process this drug a bit differently. If your springer is otherwise healthy and not on any medications, then sedation (if anything) may be the only problem.

Hello, thank you for your question. Without knowing the weight of your cat it is very hard to know what possible side effects are expected. Generally, phenobarbital when giving at a higher dosage than expected can lead to sedation. You may also notice that your cat is drinking/urinating more and has an increased appetite. If your cat develops any symptoms such as severe vomiting, sedation, weakness, or collapse I would recommend seeking veterinary care. Hope this helps!

A single dose for a dog half the bodyweight is unlikely to cause any significant effects. I would not be overly concerned but monitor for any nervous system signs and report to your vet if you notice any abnormal symptoms

Thanks for using Petco Pet Education Center, formerly Petcoach! Those are likely side effects from the phenobarbital. For that reason, I would highly recommend that you contact your veterinarian as they may decide to decrease his dose of phenobarbital based on this. Best of luck!

Phenobarbital therapy in dogs is begun at 2 to 4 mg/kg twice daily. So for a 33kg dog that would mean 66 to 132 mg twice a day. We always try to start low and increase if needed but he was essentially really underdosed in the beginning with taking 30mg twice a day. He is now on a more appropriate dose. Sedation is normal when therapy is initiated but once the dog's body gets used to the drug (after about 2 weeks) he should become more like himself. If you are really worried, you can ask the vet to run a phenobarbital level blood test to see if his dosing is too high and it can be adjusted accordingly. Please be aware that dogs will never be completely seizure free even while on anti-seizure medication. Breakthrough seizures are common but they should be pretty infrequent. If he continues to seizure or does not do well on the phenobarbital there are other medication options so please work closely with your vet.

Hello and thank you for contacting Petco Pet Education Center, formerly Petcoach. Opie will be fine. He may show signs of sedation, lethargy and sleepiness for 8-12hrs but there should not be any more worrying signs. Please, continue with the next dose of phenobarbital as normal.