Managing myasthenia gravis in dogs and cats

Background: Myasthenia gravis (MG) and congenital myasthenic syndromes (CMS) are characterised by severe muscle weakness and impaired neuromuscular transmission. CMS in dogs represent a heterogeneous group of genetic disorders affecting the motor endplate – the specialised synapse between motor neurons and skeletal muscle fibres. These disorders arise from genetic mutations in presynaptic, synaptic and postsynaptic proteins, with clinical presentations and diagnostic criteria varying across breeds. MG, on the other hand, is an autoimmune disease primarily mediated by autoantibodies targeting nicotinic acetylcholine receptors (nAChRs). While most MG patients are seropositive for nAChR antibodies, seronegative cases occur, and the absence of these antibodies does not exclude the diagnosis.

Aim of the article: This article reviews the pathophysiology, clinical features and diagnostic approaches for both MG and CMS, along with the role of immunosuppressive therapies and anticholinesterase treatments in managing these conditions. Understanding the molecular basis and treatment strategies for MG and CMS allows for accurate diagnosis and improved outcomes in affected dogs and cats.