Bromide toxicity

From Dog

Potassium bromide and bencycloquidium bromide[1] are anti-seizures medications which may result in toxic signs in dogs.

Common causes of toxicosis relate to prescription errors in formulation of this drug[2] but rare cases have been reported due to methyl bromide toxicity associated with fumigation processes in food processing[3].

The normal dose of KBr in dogs is 20 - 60 mg/kg[4].

Clinical signs include depression, lethargy, decreased proprioception and hyporeflexia, stupor, erythematous dermatitis, pancreatitis[5], conjunctivitis, nausea, anorexia, and weight loss[6][7].

Blood tests usually show hyperkalemia and hyperchloremia and testing for KBr levels in the blood frequently show bromide levels above the normal therapeutic range of 12.5 - 31 mmol/L[8].

Removal of KBr from the diet usually resolves clinical symptoms.


  1. Li J et al (2011) Subchronic toxicity and toxicokinetics of long-term intranasal administration of bencycloquidium bromide: a 91-day study in dogs. Regul Toxicol Pharmacol 59(2):343-352
  2. Piperisova I et al (2009) What is your diagnosis? Marked hyperchloremia in a dog. Vet Clin Pathol 38(3):411-414
  3. Wilson NH et al (2000) Methyl bromide 1-year dietary study in dogs. Food Chem Toxicol 38(1):115-124
  4. March PA et al (2002) Pharmacokinetics and toxicity of bromide following high-dose oral potassium bromide administration in healthy Beagles. J Vet Pharmacol Ther 25(6):425-432
  5. Gaskill CL & Cribb AE (2000) Pancreatitis associated with potassium bromide/ phenobarbital combination therapy in epileptic dogs. Can Vet J 41:555–558
  6. MacKay B & Mitchell G (1998) Spurious hyperchloraemia and negative anion gap in a dog with bromide toxicity. Aust Vet Pract 28:50–52
  7. Yohn SE et al (1992) Bromide toxicosis (bromism) in a dog treated with potassium bromide for refractory seizures. J Am Vet Med Assoc 201:468–470
  8. McConkey SE et al (2012) Compounding errors in 2 dogs receiving anticonvulsants. Can Vet J 53(4):391-394