Evaluation of coexisting polymyositis in feline myasthenia gravis: A case series

Long‐term outcome of cats with acquired myasthenia gravis without evidence of a cranial mediastinal mass

“…Anticholinesterase agents have been successfully reported in the treatment of AMG in cats . Prednisolone used at an immunosuppressive dose has also been successful in the treatment of AMG in cats and has been suggested to be more beneficial than anticholinesterase agents . Not only do corticosteroids address the underlying etiology, they can also increase neuromuscular transmission, and cats appear tolerant to the adverse effects of prednisolone, even at high doses .…”

“…In cats with AMG, these antibodies are against the nicotinic acetylcholine receptor (AChR) on the postsynaptic membrane of striated muscle . However, antibodies targeting other components of the postsynaptic membrane or skeletal muscle proteins are identified in humans and dogs with AMG, which are unevaluated in cats with the disease . Clinically, this antibody‐mediated disruption of neuromuscular transmission manifests itself through a wide range of neurological abnormalities relating to skeletal muscle weakness and fatigability …”

“…Acquired myasthenia gravis is increasingly recognized in cats, and 4 retrospective studies have characterized its clinical presentation . A large proportion of affected cats develop AMG as part of a suspected paraneoplastic syndrome associated with a cranial mediastinal mass (CMM), and immune‐mediated polymyositis (IMPM) may occur concurrently with AMG in cats whether a CMM is present or not . The relationship between these associated comorbidities and AMG is unknown.…”

“…Determination of optimal therapy is difficult given the lack of evidence and that the natural history of the disease is uncertain . Moreover, the outcome of treatment is uncertain due to conflicting results, although it is generally unfavorable in recent studies . Immune remission as defined as the absence of clinical signs of AMG along a with a normal serum anti‐AChR antibody concentration after discontinuation of treatment has sporadically been evaluated in cats but is considered uncommon despite being a frequent occurrence in dogs .…”

“…Moreover, the outcome of treatment is uncertain due to conflicting results, although it is generally unfavorable in recent studies . Immune remission as defined as the absence of clinical signs of AMG along a with a normal serum anti‐AChR antibody concentration after discontinuation of treatment has sporadically been evaluated in cats but is considered uncommon despite being a frequent occurrence in dogs . Spontaneous remission in cats as defined as the resolution of clinical signs of AMG alongside normalization of serum anti‐AChR antibody concentration in the absence of any treatment is not reported.…”