[Effectiveness of bromide in therapy resistant epilepsy of dogs]

In therapy lasting between 8 and 79 (means = 31) months 22 epileptic dogs had been unsuccessfully treated with phenobarbital and/or primidone. Both drugs had been administered in their maximum dosages. In an add-on therapy, these dogs were given potassium bromide at a rate of 17 to 58 mg/kg daily for a period of 7 to 61 (means = 21) months. We could quantitatively evaluate the seizure data from 19 of the dogs: four became free of seizures; seven showed a greater than 50% reduction in seizure frequency; in two dogs, the seizures were reduced by greater than 50% but the number of seizure-days by less than 50%; in the remaining six dogs the therapy was unsuccessful. We achieved the best therapeutic results in animals that suffered only grand mal seizures. Grand mal in addition to other types of seizures and tonic seizures were affected to a lesser extent if at all. At the beginning of the therapy we saw temporary side effects--weakness in the hind limbs and sedation; these were temporary and dependent on the dosage. Serum concentrations differed even with the same dosage among individual dogs. The therapeutic range of bromide serum concentration was from 0.7 to 2.0 mg/ml. Most of the animals tolerated concentrations up to 1.5 mg/ml quite well. To begin an add-on therapy with potassium bromide we would recommend a daily dose of 30 to 40 mg/kg. During treatment, the dose should be determined for each individual dog.