Calcinosis Circumscripta in Multiple Species of Tortoises (Testudinidae)

Chelonians are popular as pets and in zoological settings. Calcinosis circumscripta has been identified as a cause of morbidity in various chelonian species. Between 2011 and 2023, 13 tortoise (Testudinidae) samples were submitted to a private diagnostic pathology service, most commonly for a mass around the neck or submandibular region. Sulcata (Centrochelys sulcata) tortoises appeared overrepresented (10 of 13). The masses were radio-opaque, firm and multinodular with a chalky white appearance on section. Ten cases were diagnosed by biopsy and the remaining three cases were diagnosed at necropsy. Mineral analysis of one case confirmed calcium phosphate deposition. Gram-positive cocci were identified in 3 lesions. Treatment consisted of debulking and antibiotics. The lesions recurred in 4 of 10 cases. Calcinosis circumscripta should be considered as a differential diagnosis for a nodular lesion in the connective tissue of chelonians. Surgical removal provided a good quality of life depending on the location of mass. The pathogenesis of calcinosis circumscripta in chelonians is unclear, but the presence of Gram-positive cocci in some of the lesions suggests an association with bacterial granulomas.