Risk Factors and Outcomes in Cats with Acquired Myasthenia Gravis (2001-2012)

D. W. Hague, H. D. Humphries, M. A. Mitchell, G. D. Shelton

Research output: Contribution to journalArticlepeer-review


Background: Acquired myasthenia gravis (MG) in cats most commonly causes generalized weakness without megaesophagus and is more often associated with a cranial mediastinal mass, compared to dogs. Hypothesis/Objectives: To extend the clinical findings described in the report of 2000 on MG in cats (J Am Vet Med Assoc 215:55-57). Animals: Two hundred and thirty-five cats with MG. Methods: Retrospective case study to evaluate the long-term outcome and incidence of spontaneous remission in myasthenic cats. Information including signalment, clinical presentation, presence of and type of cranial mediastinal mass, treatment including surgical versus medical, survival time, and outcome including spontaneous remissions was collected and analyzed in cats diagnosed at the Comparative Neuromuscular Laboratory, University of California San Diego by detection of acetylcholine receptor antibody titers >0.3 nmol/L by immunoprecipitation radioimmunosassay. Results: Acquired MG in cats is associated with a euthanasia rate of 58%. Abyssinian and Somali cats had an increased incidence of MG compared to mixed breed cats or cats of other breeds. A cranial mediastinal mass, most commonly thymoma, was observed in 52% of the cats, which is higher than in the previous report. Spontaneous remission is not a characteristic of MG in cats. Conclusions and clinical importance: Myasthenia gravis in cats is a chronic disease associated with a high incidence of a cranial mediastinal mass. Spontaneous remission is not common and clinicians should warn owners of the necessity for long-term treatment. The clinical outcome with a cranial mediastinal mass did not differ between surgical or medical treatment.

Original languageEnglish (US)
Pages (from-to)1307-1312
Number of pages6
JournalJournal of veterinary internal medicine
Issue number5
StatePublished - Sep 1 2015


  • Acetylcholine receptor antibody
  • Feline
  • Thymoma

ASJC Scopus subject areas

  • General Veterinary


Dive into the research topics of 'Risk Factors and Outcomes in Cats with Acquired Myasthenia Gravis (2001-2012)'. Together they form a unique fingerprint.

Cite this