Systemic calcinosis in a Quarter Horse gelding homozygous for a myosin heavy chain 1 mutation

Beatrice T. Sponseller, David M. Wong, Rebecca Ruby, Wendy A. Ware, Scott Wilson, Joseph S. Haynes

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


Case Description: A 9-year-old Quarter Horse gelding was presented for lethargy, decreased appetite, polyuria and polydipsia (PU/PD), and severe muscle wasting suggestive of immune-mediated myositis. Clinical Findings: The horse displayed lethargy, fever, tachyarrhythmia, inappetence, PU/PD, and severe epaxial and gluteal muscle wasting. Clinicopathologic findings were consistent with previously reported cases of systemic calcinosis in horses, including increased muscle enzyme activity, hyperphosphatemia, increased calcium-phosphorus product, hypoproteinemia, and an inflammatory leukogram. A diagnosis of systemic calcinosis was established by histopathologic evaluation of biopsy specimens from skeletal muscle, lung, and kidney. Treatment and Outcome: Symptomatic treatment was complemented by IV treatment with sodium thiosulfate to reverse calcium-phosphate precipitation in soft tissue and PO aluminum hydroxide to decrease intestinal phosphorus absorption and serum phosphorus concentration. Clinical Relevance: This is the first report in the veterinary literature of an antemortem diagnosis of systemic calcinosis in the horse that was successfully treated and had favorable long-term outcome.

Original languageEnglish
Pages (from-to)1543-1549
Number of pages7
JournalJournal of Veterinary Internal Medicine
Issue number4
StatePublished - Jul 2022

Bibliographical note

Publisher Copyright:
© 2022 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC. on behalf of the American College of Veterinary Internal Medicine.


  • calcium-phosphorus product
  • immune mediated myositis
  • polydipsia
  • polyuria
  • sodium thiosulfate

ASJC Scopus subject areas

  • General Veterinary


Dive into the research topics of 'Systemic calcinosis in a Quarter Horse gelding homozygous for a myosin heavy chain 1 mutation'. Together they form a unique fingerprint.

Cite this