Simple Summary Acquired myasthenia gravis is an immune-mediated neuromuscular disease caused by autoantibodies directed against the neuromuscular junction, which leads to skeletal muscle weakness. The acute fulminant form is defined as rapidly progressive generalized weakness and can lead to a life-threatening condition caused by the paralysis of respiratory muscles. Traditional management consists of acetylcholinesterase inhibitors and nutritional management. This case report shows a new therapeutic option for this acute life-threatening condition. The dog was mechanically ventilated for respiratory failure due to acquired myasthenia gravis and immunoadsorption, an extracorporeal blood purification technique, was performed. During immunoadsorption, blood is purified in an extracorporeal circuit using an adsorber that binds circulating autoantibodies. After immunoadsorption, the dog was successfully weaned from mechanical ventilation and further treated with medical management.Abstract A one-year-old, female intact Samoyed, 12.5 kg, was presented with coughing for 2 weeks, progressive appendicular and axial muscle weakness, megaesophagus and labored breathing for 5 days. There was no improvement with standard treatment. Acquired myasthenia gravis was suspected and the dog was referred with increasing dyspnea. At presentation, the dog showed a severely reduced general condition, was non-ambulatory and showed abdominal and severely labored breathing. A marked hypercapnia (PvCO2 = 90.1 mmHg) was present in venous blood gas analysis. The serum anti-acetylcholine receptor antibody test was consistent with acquired myasthenia gravis (2.1 nmol/L). The dog was anesthetized with propofol and mechanically ventilated with a Hamilton C1 ventilator. Immunoadsorption was performed with the COM.TEC (R) and ADAsorb (R) platforms and a LIGASORB (R) adsorber to eliminate anti-acetylcholine receptor antibodies. Local anticoagulation was performed with citrate. Treatment time for immunoadsorption was 1.5 h with a blood flow of 50 mL/min. A total plasma volume of 1.2 L was processed. Further medical treatment included intravenous fluid therapy, maropitant, esomeprazole, antibiotic therapy for aspiration pneumonia and neostigmine 0.04 mg/kg intramuscularly every 6 h for treatment of acquired myasthenia gravis. Mechanical ventilation was stopped after 12 h. A percutaneous gastric feeding tube was inserted under endoscopic control on day 2 for further medical treatment and nutrition. A second treatment with immunoadsorption was performed on day 3. Again, a total plasma volume of 1.2 L was processed. Immediately after this procedure, the dog regained muscle strength and was able to stand and to walk. After 6 days, the dog was discharged from the hospital. This is the first report of immunoadsorption for emergency management of a dog with acute-fulminant acquired myasthenia gravis. Immunoadsorption may be an additional option for emergency treatment in dogs with severe signs of acquired myasthenia gravis.
