Massive osteolysis in a dog resembling Gorham's disease in humans.

An eight-month-old mixed-breed dog was presented with a history of sudden onset pelvic limb lameness. Radiographic and computed tomographic examinations demonstrated an osteolytic process involving the lumbar spine and pelvis. A comprehensive work-up including serial radiographic skeletal survey, biopsy, routine laboratory investigation and evaluation of parathyroid hormone (PTH) and 25-hydroxy-vitamin D levels failed to reveal any underlying cause for the osteolysis. Conservative treatment using the bisphosphonate drug alendronate and oral analgesic medications resulted in a return to nearly normal long-term function, despite massive lumbar and pelvic osteolysis. The clinical, radiological and histopathological features in this dog are reported, and similarities with the human condition known as Gorham's disease are discussed.

Multicystic bone disease (Gorham-Stout syndrome) in a spider monkey (Ateles geoffroyi ).

BACKGROUND: In April 2000, a 2.5-year-old pet female Geoffroyi's spider monkey presented for reduced activity, a subdued demeanor, and boney enlargement involving both radii. METHODS: On further examination, polyostotic bone cysts were identified involving many of the tubular bones and were identified radiographically. Microscopic examination of a bone biopsy revealed hemorrhage and other characteristics typical of an aneurysmal bone cyst. In addition, excessive osteoclasia was noted, in association with fibrotic areas rather than with Howship's lacunae as expected from a growing animal. RESULTS: These findings were consistent with Gorham-Stout syndrome, a rare condition reported previously in ∼175 human cases and in a dog at necropsy. The diet history and further testing suggested a negative calcium balance. Treatment included the administration of bis-phosphonates, which appeared to bring about marked improvement. Almost 8 years later (November 2008), radiographs were again taken and suggested some resolution of bone cysts, primarily those in the legs. CONCLUSIONS: This represents the first reported case and a potential therapy for this rare condition in a non-human primate.

Hemangiomatosis associated with osteolysis of the mandible in a dog resembling Gorham-Stout disease in humans.

A 6-month-old female German Shepherd Dog died as a result of profuse oral bleeding. At postmortem examination, the oral cavity showed visible roots of the right mandibular fourth premolar and first molar teeth and, in addition, they were very mobile and compressible. Radiographs showed a generalized radiolucency in the body of the right mandible, with evidence of resorption of the affected alveolar bone. Histologically, the lesion of the right mandible was characterized by the lysis of bony structures and a non-malignant proliferation of blood-filled vascular spaces lined by a single layer of well-differentiated endothelial cells. The clinical, radiographic, and histologic presentation of this dog is consistent with that associated with Gorham-Stout disease, a rare bone disorder in humans.

Idiopathic multifocal osteopathy in four Scottish terriers (1991-1996).

This case series describes four Scottish terriers with an osteopathic condition, characterized by multifocal absence of bone in the skull, cervical spine, and proximal radii, ulnae, and femora. All dogs were affected clinically; two dogs were euthanized due to progression of the disease, one died acutely, and one was euthanized for an oral melanoma. Histopathology in one case was characterized by osteoclastic osteolysis and replacement of bone with fibrous tissue. This disease has some characteristics of human osteolysis syndromes. Three of the dogs were related through pedigree analysis, and the pedigree of the other dog was not available. The name, idiopathic multifocal osteopathy, is used to describe a new disease in dogs, found particularly in Scottish terriers.