• Potassium bromide is a medication used to control or prevent seizures.
  • A potassium bromide level test is used to determine if the dose is appropriate to control seizures without causing harmful side effects.
  • The test requires a simple blood sample at your veterinarian’s office.
  • Signs of potassium bromide toxicosis include sedation, rear-limb weakness, and incoordination (lack of coordination of muscular action, such as limb movement).
  • In animals with signs of potassium bromide toxicosis, the medication should be discontinued and then restarted at a lower dose or changed to another medication.

Potassium bromide is used alone or in combination with other anti-convulsant medications to help control and prevent seizures. Potassium bromide is administered primarily to dogs and less frequently to cats.

What Is a Potassium Bromide Level Test?

A potassium bromide level test is a simple blood test that measures the amount of potassium bromide in the blood. Your veterinarian may recommend this test to determine if the dose of potassium bromide is appropriate to control your pet’s seizures without producing harmful effects. The blood test can be performed at your veterinarian’s office on an outpatient basis.

When Should Pets Receive This Test?

After starting potassium bromide therapy, it usually takes 2 to 3 months for the medication to reach an optimal level in the blood. A potassium bromide level test may be recommended:

  • 1 to 2 months after initiating treatment
  • 4 months after initiating treatment
  • Any time a dose is changed
  • If concurrent medications are altered
  • If the patient gains or loses weight
  • If seizures aren’t controlled at the current dose
  • If the patient experiences signs of toxicosis
  • Every 6 months after seizures have been controlled

What Are the Signs of Potassium Bromide Toxicosis?

When animals begin potassium bromide therapy, especially while receiving phenobarbital, they may experience some sedation. These signs should resolve in a few weeks. Other potential side effects include increased drinking and urination, changes in appetite, vomiting, and constipation.

Older animals with additional diseases may be more prone to side effects. Signs of toxicosis include sedation, mental dullness, tremors, incoordination, and hindlimb weakness. If you notice any of these signs in your pet, contact your veterinarian immediately.

Signs of potassium bromide toxicosis may also appear if the pet is switched to a low-salt diet. At the same time, increases in dietary salt, from a dietary change or high-salt treats may reduce the potassium bromide level, increasing the risk of seizures. If your pet is receiving potassium bromide therapy, dietary changes should not be made without consulting your veterinarian.

How Is Potassium Bromide Toxicosis Treated?

When animals experience signs of potassium bromide toxicosis, the medication is usually discontinued for a few days. The veterinarian may recommend that the pet be hospitalized to receive intravenous fluids. The medication may then be restarted at a lower dose, or the animal may be given a different medication instead.