The Role of Magnesium in the Management of Acute and Long-Term Symptoms Caused by Tetanus in Two Dogs.

Tetanus in dogs is a relatively uncommon neurological disease caused by the sporogenic bacillus Clostridium tetani. This disease is associated with prolonged hospitalization and mortality rates from 8%-50%. A 2-year-old, neutered male King Charles Spaniel and an approximately 8-months-old female Mongrel dog presented to Companion Animal Clinic with symptoms of muscle rigidity and generalized stiffness. A tentative diagnosis of generalized tetanus was made in both dogs. Treatment consisted of IV fluids, antibiotics (metronidazole), human tetanus antitoxin, analgesics and supportive care. Muscle relaxation was provided by midazolam. Acetylpromazine meleate was added to the treatment of the second dog to better control excitability. Each dog received magnesium therapy on the 10th and 3rd days, respectively; which was provided per os to the first dog and constant rate infusion (4 mg/kg/h) to the second dog. The addition of magnesium helped to increase muscle relaxation and increased the time interval between acetylpromazine administration. On the tenth day, magnesium sulfate was discontinued from the second dog and magnesium aspartate (12 mg/kg), twice a day, per os was administered in both animals. Further muscle relaxation was noted in both dogs with a substantial reduction of tetanus symptoms. Both dogs were discharged from Intensive Care Unit on the 14th and 13th day respectively with sole treatment of magnesium aspartate (12 mg/kg) orally, twice a day. Magnesium aspartate was continued for 14 days and 12 days respectively. Both dogs had progressive reduction of muscle rigidity and the first dog recovered completely. The second dog presented again with muscle rigidity and increased spinal reflexes after the discontinuation of magnesium aspartate, thus therapy with magnesium aspartate was started again and symptoms subsided after the second oral dose of magnesium. Therapy was continued for two more weeks during which muscle rigidity subsided and then was stopped. At that time, tetanus symptoms did not relapse and the dog was considered fully recovered. According to the findings of this case series, magnesium therapy may provide further muscle relaxation during the standard therapeutic protocol of tetanus in dogs. In addition, long term symptoms of the disease were adequately managed with the administration of magnesium aspartate, orally.