Potassium Bromide for Seizure Treatment in Dogs and Cats

Female veterinarian holding a little dog in her arms
NickyLloyd / Getty Images

A seizure is a sudden episode of abnormal brain activity that may cause a loss of overall body control. Seizures are frequently seen in both dogs and cats. Epilepsy is sometimes the cause of seizures in both dogs and cats, No matter the cause, seizures can be frightening to witness. Fortunately, there are medications that treat seizures in pets. Potassium bromide is one of these medications. Here’s what to expect if your pet needs potassium bromide treatment.

Potassium Bromide for Cats and Dogs

Potassium bromide, sometimes abbreviated as KBr, is one of the traditional anticonvulsant medications used to treat canine and feline epilepsy. It can be used by itself to control seizures, but if needed, it can be combined with other anticonvulsants like zonisamide, levetiracetam, or phenobarbital (link Spruce Pets articles for each?) to attain the desired effect.

When starting potassium bromide, your vet might recommend an initial dose that is higher than the recommended maintenance dose. This is called a “loading dose” and it may be given over a one-to-five day period.

Once your pet is started on potassium bromide, you should not suddenly stop giving the medication unless advised by your veterinarian. If potassium bromide can or should be discontinued, it is best to slowly taper the dosage.

Blood tests should be monitored periodically while your pet is receiving potassium bromide. Levels of bromide in the blood can be measured and may be recommended. Other blood tests to check liver enzymes and potassium levels may be recommended as well.

Seizure activity should be monitored. Side effects should also be monitored and your veterinarian should be notified of any seizure activity your pet experiences or any side effects that occur.

The diet of a dog or cat receiving potassium bromide should not be altered without speaking first with your veterinarian. Altering the diet can affect the metabolism of potassium bromide and make dosing difficult.

Side Effects 

As with any medication, potassium bromide does have the potential to cause side effects in both dogs and cats. The use of potassium bromide is generally contradicted in cats.

In dogs, the side effects that may be seen with potassium bromide include:

  • Increased appetite
  • Increased thirst
  • Increased urine production
  • Lack of appetite
  • Vomiting
  • Constipation
  • Coughing


The toxic effects associated with a dosage of potassium bromide that is too high include:

  • Profound sedation to stupor
  • Incoordination
  • Tremors
  • Paralysis of hind legs
  • Other central nervous system symptoms

Pancreatitis has also been diagnosed in dogs receiving potassium bromide together with phenobarbital. However, it is not known how this is related to potassium bromide administration.

In cats, potential side effects include:

  • Increased appetite
  • Weight gain
  • Sedation
  • Increased water consumption
  • Coughing
  • Difficulty breathing, which can be fatal

Be sure to talk to your veterinarian if you feel the side effects are impacting your pet’s quality of life. You should see your veterinarian as soon as possible if you notice signs of toxicity. If potassium bromide is not working well for your pet, remember not to suddenly stop it. Instead, contact your veterinarian to discuss other treatment options.


Plumb's Veterinary Drug Handbook, 6th edition, Donald C Plumb

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.
Article Sources
The Spruce Pets uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. https://pubmed.ncbi.nlm.nih.gov/12387381/