Calcium hydroxylapatite deposition disease in a Great Dane Puppy

Severe Hydroxyapatite Deposition Disease in Binturongs (Arctictis binturong)

In a collection of 6 young binturongs (Arctictis binturong), 3 presented with anorexia, lethargy, and footpad swelling diagnosed by surgical biopsy as calcinosis circumscripta. Despite supportive care over the next 4 years, affected binturongs had progressive weight loss, hyperphosphatemia, and hyperkalemia and developed large radiodense deposits in tissues adjacent to appendicular joints, thoracolumbar vertebrae, and the sternum. Two binturongs died and necropsies showed severe periarticular mineral deposition with fibrosis and granulomatous inflammation. Additionally, binturongs had mineralization of distal renal tubules, mineralization of the renal interstitium, and marked mineralization of the pulmonary interstitium and peribronchiolar smooth muscle. Foot biopsies from the surviving binturong were evaluated by spectroscopic microanalysis and were positive for hydroxyapatite, Ca₁₀(PO₄)₆(OH)₂. Periarticular and footpad mineralization in these binturongs is consistent with hydroxyapatite deposition disease, which is rarely described in humans and animals as a primary familial condition or a secondary condition often associated with renal injury.

Imaging diagnosis: Multiple cartilaginous exostoses and calcinosis circumscripta occurring simultaneously in the cervical spine of a dog

An 8-month-old female Saint Bernard dog was presented with gait abnormalities consistent with a left-lateralizing cervical myelopathy. Imaging revealed a large, irregular soft tissue and mineral mass at the level of C1 and C2. The lesion was successfully excised, and histopathology was performed, revealing evidence of both multiple cartilaginous exostoses and calcinosis circumscripta. To the authors' knowledge, this is the first report comparing features using magnetic resonance imaging, computed tomography, and radiography. Additionally, multiple cartilaginous exostoses have not previously been reported to occur in combination with calcinosis circumscripta.

Calcinosis circumscripta in the dog: a retrospective pathological study

Calcinosis circumscripta is an uncommon syndrome of ectopic idiopathic, dystrophic, metastatic or iatrogenic mineralization characterized by deposition of calcium salts in soft tissues. This paper is a retrospective study of 77 canine cases. The age of dogs in the study varied from 4 months to 15 years and 55% were <1 year old, 74% <2 years old and 88% <4 years old. Several pure and mixed, typically large breed dogs were affected so that 28.6, 13 and 9% were German Shepherd, Rottweiler and Labrador Retriever respectively. The size of lesions varied from 2 mm to 13 cm in diameter but most lesions were between 0.5 cm and 3 cm in diameter. Lesions were solitary in 82% of the affected dogs, and occurred most commonly on the hind feet (50%) and tongue (23%). With multiple lesions there was no apparent body symmetry. Microscopically, most lesions were well-defined single or multiple variably sized aggregates of amorphous to granular, lightly to darkly basophilic material with or without peripheral granulomatous reaction and surrounded by varying amounts of fibrous connective tissue. Additionally, three small nodular masses in the wall of the jejunum of a dog were diagnosed as calcinosis circumscripta. This is the first reported case of idiopathic intestinal calcinosis circumscripta in the dog.