Phenobarbital for Dogs: Your Go-To Guide

Phenobarbital for Dogs: Your Go-To Guide

  • Kirsten Thornhill - 10.08.2020

Your fur babies mean the world to you. Trust us, we totally get it! At Petly CBD, we are all paw parents and animal lovers. We know just how challenging it can be when something happens with your four-legged friend. It’s even worse when you’re experiencing it right before your eyes, knowing there is only so much you can do. 

In today’s article, we’ll be talking about dogs with seizures and epilepsy. The first time your doggo experiences a convulsion will be extremely difficult to experience. Once it’s over, however, the reality of the situation must be addressed. As a paw parent, what do you do next? There are some extremely important things to know about seizures in dogs and the medications that are associated with treating them. Being prepared with knowledge about the potential risks involved is crucial before starting any treatment. 



We’ll dive into the population medication used to treat epilepsy and seizures, called phenobarbital. The harsh reality of this drug may leave you completely surprised and will most likely have you considering whether or not the risks are worth the reward. 

We’ll talk about alternatives to the drug and ways that you can ensure that your best fur friend, regardless of their diagnosis. 

1, 2, 3, let’s get to it!

Understanding Dog Seizures 101

Before we start talking about all there is to know about phenobarbital, it’s imperative that we first understand your pup’s disorder. Studies have shown that up to 5% of all puppers suffer from seizures.


So many paw parents don’t completely know what having a dog that experiences seizures completely entails. During the postictal phase post-seizure, your pet may show signs of disorientation, ataxia, pacing, and potential blindness. 

Wait, what’s the difference between seizures and epilepsy? Epilepsy is a term used to describe the repeated episodes of seizures that occur.


Seizures in Dogs: The Cause


Many pet parents wonder how and if they can help prevent seizures and epilepsy from occuring in the first place. Was it something you could have done prior? 


Well, the truth is….the majority of seizure disorders are referred to as idiopathic epilepsy. Idiopathic epilepsy is an inherited condition in which experts and researchers are still unsure of the exact origin and cause. It’s a diagnosis of exclusion of other causes for seizures. Most dogs that are diagnosed with idiopathic epilepsy are between the ages of 1 - 5. 




In other instances, seizures may develop due to the following:


  • Kidney failure
  • Brain trauma 
  • Brain tumor
  • Anemia
  • Infectious diseases
  • Liver disease
  • High or low blood sugar
  • Toxins

Diagnostic measures such as radiographs, ultrasound, MRI scans, and blood work will be necessary to determine the underlying cause of seizures. *Heavy sigh*


The Breeds Most Prone to Seizures


Seizures can occur in any dog, but certain breeds are at higher risk of the disorder, unfortunately. 



Common breeds include:

  • Beagle

  • Belgian Tervuren

  • Cocker Spaniel

  • Golden Retriever

  • Keeshond

  • Labrador Retriever

  • Schnauzer

  • Shetland Sheepdog

  • Basset Hound


    It’s super important for paw parents to be aware of the risks associated with their dog’s specific breed. For example, Great Danes are at a higher predisposition for heart disease and Boston Terriers are at a higher risk of developing glaucoma. Finding out whether or not your dog is at a higher risk of any disorder will ensure that you know the beginning symptoms of development and can help prevent them from worsening. 


    What to do if Your Dog is Epileptic


    When your dog is having a seizure, one of the most important things you can do as a paw parent is to make sure their surroundings are as quiet and calm as possible. Also, make sure that your pup is away and safe from any potential hazards.



    Don’t ever place your hands near their mouth when they’re seizing, as they are unconscious and may bite you. Seizures do not cause any pain to the dog, but bright lights, loud noises, and stress can cause the seizures to worsen as well as potentially cause additional episodes to occur. 


    When to Start Anti-Seizure Medication


    Therapy should be started for any dog that fits into the following categories, according to the American College of Veterinary Internal Medicine:


    • If the seizure lasts longer than 5 minutes
    • Cluster seizures (3 or more) happening in a 24 hour period
    • If the dog has a history of trauma or brain injury
    • If there is a visible brain lesion on imaging (MRI)
    • If the seizure is severe
    • Breeds that are known to have difficulty controlling seizures



    What is Phenobarbital?


    Now that you’ve got a solid understanding of seizures, let’s talk phenobarbital for dogs. 


    Phenobarbital for dogs is one of the most commonly prescribed medications for controlling the severity and frequency of seizures and epilepsy. It is a widely utilized first choice anti-seizure medication because of its effectiveness, easy-to-use dose, and its reasonable price. This drug is most widely known by its generic name, but is available in several names such as Barbita or Luminal.


    Phenobarbital can be used alone or in conjunction with other drugs to better treat epilepsy in doggos. It is available in different sized capsules, tablets, injectables, or liquids.


    How Does Phenobarbital Work for Dogs?


    Well, a seizure occurs due to an unexpected surge in neuronal activity, within the brain. Phenobarbital works to minimize the severity and frequency of seizures by decreasing neuronal activity within the brain. This drug also helps decrease the neurotransmitter glutamate, which is responsible for stimulating nerves. 



    Phenobarbital for Dogs: The Dosage


    The appropriate dosage of Phenobarbital will differ significantly between different breeds of dogs. It is important that your veterinarian decides on the accurate dose after careful consideration of your doggo’s weight, seizure severity, as well as how often they are occurring. 


    In most instances, your vet will advise you to administer Phenobarbital every 12 hours. The typical starting dose of Phenobarbital for dogs is around 1 mg per pound of body weight. 


    With all drugs in general, it’s important that you do not miss a dose as it can cause your dog to have an even more severe seizure episode. 


    If for any reason you do miss a dose, DO NOT double up on the next dose. Nope. Zip. Never. Big N to the O. 


    Give your pup the missed dose as soon as possible and then carry on with your normal dosing routine, accordingly. 


    The Precautions of Phenobarbital


    Before we start talking about the nasty side effects associated with Phenobarbital, there is a slew of dogs who should not be taking it, to begin with. It’s important that your vet knows about everything when it comes to your dog’s health history in order to know whether or not Phenobarbital is an appropriate medication for your puppers.


    Dogs Who Should NOT Take Phenobarbital


    If your dog has any of the following health ailments or condition, they should NOT take Phenobarbital:


    • Anemia
    • Respiratory problems
    • Heart disease
    • Liver disease
    • Kidney disease
    • Addison’s disease
    • Hypovolemia

    In addition, the following conventional medications have been shown to interact with phenobarbital:


    • Anticoagulants
    • Antihsitamines
    • Beta-adrenegic blockers
    • Corticosteroids
    • Griseofulvin
    • Rifampin
    • Theophylline
    • Valproic acid
    • Diazepam 
    • Doxycycline
    • Furosemide
    • Aminophylline
    • Quinidine
    • Opiate agonist
    • Phenothiazine

    Phenobarbital Side Effects


    The associated side effects are enough to convince anyone to learn more about this popular medication. Here are 8 common potential adverse reactions to Phenobarbital for dogs:


    1. Excessive Urination and Thirst


    If you notice that your four-legged friend is frequently needing a water-bowl refill, it’s likely a side effect of the medication. 




    2. Excessive Weight Gain and Hunger


    Many canine parents have found that their dog is excessively hungry when taking Phenobarbital. All of the extra food intakes can often lead to an excessive gain in weight, especially if the medication also alters their normal food intake. 


    3. Increased Anxiety


    Phenobarbital can cause your dog to feel high levels of anxiety and feelings of uneasiness. As we mentioned above, anxiety can cause seizures to worsen and occur more frequently. 


    4. Depression


    Like us humans, dogs can experience depression too. If you notice that your dog is sleeping longer and more frequently than usual or seems more down, the medication may be the one to blame. 



    5. Ataxia


    The medication may cause your dog to lose their coordination in their back limbs in addition to the experiencing bouts of weakness, inhibiting their ability to move freely. This is commonly seen when starting the medication, with improvements over time. 


    6. Hyperexcitability


    While some doggos make experience more tiredness, some may experience the opposite: agitation or hyperexcitability. If you find that your dog is pacing back and forth, acting restless, panting without any reason, or being super vocal, it’s most likely a side effect of Phenobarbital. 


    7. Lethargy


    Similar to the symptoms of depression, the medication may also cause your pup to be very lazy and lethargic, appearing to have no interest in things they previously enjoyed. This side effect typically blends in in nature. But, it could too be a sign that the dose is too high for your doggo. 



    8. Anemia


    In very rare cases, Phenobarbital may cause anemia to develop. Signs of anemia include lethargy and pale gums. If you feel that the medication has cause the development of an additional disease, talk to your vet.

    Phenobarbital for Dogs: Final Thoughts


    At the end of the day, we know that you only want the very best for your fur baby. With the constant growth in both traditional and holistic medicine, we truly feel that paw parents of epileptic dogs have numerous safe and effective options available for them.



    As a paw parent, you must ensure that you keep up with your dog’s condition and learn everything you can about it, making educated decisions for their overall well-being. In many instances, this may mean forgetting the Phenobarbital. 


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