A 7 month old female English bulldog presented with severe non-painful bilateral mandibular swelling. What are your rule outs?
Answer: Periostitis ossificans, craniomandibular osteopathy (CMO), renal secondary hyperparathyroidism and less likely calvarial hyperostosis.
The body of the mandible from just rostral to the ramus to the second premolar was affected.
This is a radiograph of the right ventral mandible. A mottled appearance to the bone and lack of a cortex are striking features. This is consistent with CMO described previously in the English bulldog. (see reference below)
The course and severity are variable. Patients may be asymptomatic or experience varying degrees of pain. CMO can be life threatening/life ending due to severe bony proliferation around the TMJ, causing inability to open the mouth. Calvarial hyperostosis is considered in cases with TMJ involvement.
This is a ventrodorsal view of the body of the left mandible. This condition resembles calvarial hyperostosis. In this publication, Thompson proposes a new term Idiopathic Canine Juvenile Cranial Hyperostosis for CMO and Calvarial Hyperostosis, theorizing that this is one disorder with predilection sites that vary by breed.
Thompson DJ, Rogers W, Owens MC, Thompson KG, Idiopathic canine juvenile cranial hyperostosis in an immature Pit Bull Terrier. New Zealand Vet J, 2011;59, 201-205.
(Thanks to Bonnie Shope, VMD, Diplomate AVDC for sharing this reference)
ARS VETERINARIA, Jaboticabal, SP, v.28, n.4, 218-221, 2012. CRANIOMANDIBULAR OSTEOPATHY IN ENGLISH BULLDOG CASE REPORT G. R. VARALLO1*, B. R. LIMA2, T. M. M. RAPOSO2 , C. R. DALECK3
Craniomandibular osteopathy is a proliferative, nonneoplastic, degenerative bone disorder, which is uncommon in dogs. It affects, mainly, the skull bones, and possibly the long bones. This disease affects more immature dogs, from three to eight months old, prepubertal, of the West Highland and Scottish terrier breeds. It is a self-limiting disease with no sex predilection. The main clinical signs are basically enlarged and painful jaw, drooling, and intermittent fever as well. Diagnosis is based on clinical, radiographic and histopathological examination. The treatment is based on pain control.
Additional References on Pubmed