Potassium Bromide

Written By Mel Lee-Smith
Published: 09/04/2020Updated: 08/30/2021
Potassium Bromide for Dogs | Wag!

Potassium bromide treats seizures and convulsions in dogs. Potassium bromide is the most common type of bromide used in veterinary medicine along with sodium bromide. In modern medicine, phenobarbital is preferred to potassium bromide as it is safer to administer and cheaper to make. As a result, potassium bromide is typically combined with phenobarbital or prescribed to animals with an intolerance to phenobarbital.

While potassium bromide is safe to use when administered correctly, issues can arise due to allergic reactions, drug interactions, and preexisting conditions. Here's everything you need to know about your dog and potassium bromide.


As mentioned, potassium bromide is generally used in addition to phenobarbital as an antiepileptic and anticonvulsant medication. Another reason potassium bromide is utilized less often in modern medicine is it takes a long time to yield positive results. Potassium bromide can take around 4 months to start controlling convulsions and seizures.

As it takes several months for potassium bromide to take effect, your vet will give your dog what's known as a loading dose to quickly raise the potassium bromide levels in your dog's blood. This loading dose is administered orally over several days. 

Potassium bromide is taken orally in either liquid, tablet, or capsule form. You should give your dog potassium bromide with food, as it is known to induce vomiting and diarrhea when taken on an empty stomach.

Your vet will usually prescribe your dog a dose of potassium bromide daily; however, if this medicine is upsetting your dog's stomach, they may advise you to try smaller doses. If you are giving a liquid solution to your dog, you'll need to inject it directly into their mouth with a plastic, needleless syringe. If you are struggling with this method, you can apply potassium bromide directly to food. Ensure you administer the correct amount of potassium bromide — too much can lead to bromide toxicity.

Dosage instructions

The loading dose your doctor will give your dog will be much larger than the standard daily dosage and can be anywhere from 400 to 600 mg per kg. After the initial loading dose, your dog will be given around 15 to 35 mg per kg daily. 

You may find your vet has a different treatment plan for your dog dependent on preexisting conditions, the severity of their illness, and drug interactions. Always consult your vet and follow their instructions closely when administering potassium bromide.


The cost of potassium bromide for dogs depends on the dosage strength. A bottle of 60 500-mg tablets costs $35 on average. The same average price applies to liquid forms with a dosage of 250 mg/ml.


Potassium bromide is very effective at preventing seizures and convulsions; however, it does take a few months to start working. Phenobarbital is often used instead of potassium bromide because it’s less likely to cause adverse side effects and drug interactions. As the level of potassium bromide in a dog's bloodstream reduces the risk of seizure, you shouldn't stop giving your dog this drug suddenly. Your dog should be slowly weaned off of potassium bromide. Consult your vet and follow their advice about changing your dog's treatment.

Side effects

Common side effects associated with potassium bromide include:

More serious side effects related to potassium bromide include:

If your dog experiences any of these symptoms, contact your vet as soon as possible.


Drug interactions

There are a few different classes of medication that should be used cautiously with potassium bromide. These include:

  • Diuretics

  • Anti-seizure medications

  • Sedatives

  • IV fluids with a high sodium content

If you're giving your dog any supplements or vitamins, let your vet know about them. Some supplements may contain salt, which will increase the chances of seizures, as salt decreases the potassium bromide levels in your dog's blood.

Allergic reactions and sensitivity

Dogs can have an allergic reaction to potassium bromide. If your dog is showing signs of an allergic reaction, contact your vet immediately. Potassium bromide shouldn't be given to dogs who have kidney disease. Let your vet know if your dog is taking potassium bromide and is pregnant or has another severe chronic illness.

Sodium will lower the potassium bromide levels in your dog's blood, which will increase the risk of seizures. As a result, you should keep your dog on a healthy diet and avoid giving them table scraps. Let your vet know if you are changing your dog's diet regardless of salt levels. Different diets can cause the body to metabolize potassium bromide at different rates, increasing the risk of seizure or bromide toxicity.

Frequently asked questions

Is it safe to give cats potassium bromide?

Potassium bromide is safe to give to cats when prescribed by a veterinarian. However, cats are known to have a higher incidence rate than dogs, so your vet may prescribe a different medication. 

What should I do if I forget to give my dog a dose of potassium bromide?

If you forget to give your dog a dose of potassium bromide, it may increase the risk of seizures. If you do forget to give a dose, administer it as soon as possible. However, if it is getting close to time for their next dosage, skip the one they missed. Do not give your dog more than the recommended amount of potassium bromide, as this can lead to bromide toxicity. If you have any questions or concerns about missed dosages, contact your vet.

Will my dog need to be monitored while taking potassium bromide?

Your vet will take blood tests frequently at first to ensure blood levels of potassium bromide are normal. These blood tests are important, as dogs metabolize potassium bromide at different rates. Once the correct dosage has been found, your vet will likely take blood tests a few times a year.

What if potassium bromide doesn't stop my dog's seizures?

Potassium bromide takes a few months to yield results, so be patient and wait for an improvement. Do not adjust your dog's diet or dosage on your own without consulting your veterinarian first.

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