July 2007

Dog: Craniomandibular osteopathy

Craniomandibular osteopathy is a proliferative bone disease of young dogs characterised by irregular new bone formation and first reported in West Highland white terriers in 1958 but subsequently reported in a number of breeds. Bones of the skull are primarily affected although occasionally affecting the metaphyses of long bones (femur, radius and ulna). The West Highland White Terrier is overrepresented and an autosomal recessive mode of inheritance has been suggested. Case contributed by Rob Pettitt

August 2007

Dog: Cutaneous Histiocytoma

Histiocytomas are common benign tumours of epidermal Langerhans cells, a form of dendritic histiocyte. They occur most often, but not exclusively, in young dogs, as a solitary, not infrequently ulcerated nodule which grows rapidly over a few weeks. The head and limbs are the most common sites affected. Occasionally there are multiple nodules and rarely lymph nodes are affected. The majority of both primary and secondary tumours undergo spontaneous immune-mediated regression, usually within weeks to months. Cytologically cells are larger than neutrophils, have moderate pale basophilic cytoplasm and an ovoid to often indented nucleus. Nucleoli are often not seen. Mitoses maybe evident (Speedy Diff)

September 2007

Canine Skin: Cutaneous angiomatosis

Cutaneous angiomatosis is a benign but variably progressive proliferative lesion of vascular tissue involving the dermis and subcutaneous tissues of dogs and cats. In one recent report, however, biopsy of a lesion on the antebrachium in a young dog revealed a widely disseminated and infiltrative-like pattern of benign-appearing small blood vessels, which were throughout the superficial and deep dermis and subcutis. Although the disseminated nature suggests malignancy, the histologic appearance of well-differentiated small blood vessels and non-progressive clinical features in this case indicated that the lesions were benign.