Idiopathic canine juvenile cranial hyperostosis in a Pit Bull Terrier

An 8-month-old male Pit Bull Terrier was presented with bilateral firm swellings of the cranium in the region of the frontal sinuses. The dog was aggressive when approached and had also been anorexic during the 3.5 days prior to presentation.

Using computed tomography (CT) and radiology, periosteal new bone formation and hyperostosis were detected on the frontal, parietal and mandibular bones bilaterally. Histopathology of the calvarial and mandibular bones was similar, comprised of thick trabeculae of immature woven and mature lamellar bone separated by cementing lines. Sites of prominent osteoblastic and osteoclastic activity were also present.

Craniomandibular osteopathy with clinical similarities to calvarial hyperostosis.

Pit Bull Terriers are not predisposed to either craniomandibular osteopathy or calvarial hyperostosis. This observation, in addition to the clinical and pathological similarities between the two diseases, suggests that craniomandibular osteopathy and calvarial hyperostosis may represent a single disorder, with predilection sites that vary between breeds of dog. We propose a new term, idiopathic canine juvenile cranial hyperostosis, for this disorder, to include both craniomandibular osteopathy and calvarial hyperostosis.