January 2007

Hypotrichosis and alopecia in Irish Water Spaniels (IWS)

Dogs have a non-pruritic, non-inflammatory, regionalized hair loss affecting the same areas of the body in males and females. Affected animals have more or less extensive focal areas of hair loss affecting the ventral and lateral neck, rump, trunk, or the thighs. Hormonal investigations showed features suggestive of an abnormality of steroidogenesis. Histopathology reveal features similar to canine recurrent flank alopecia and follicular dysplasia associated with abnormal melanisation. Dietary changes improved coat and skin quality in some cases studied. Studies suggests that hair loss in IWS is influenced by dietary factors and sexual hormones.

February 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)

March 2007

Uveodermatologic (VKH like) syndrome

Uveodermatologic syndrome is a debilitating disease in the dog, resulting in blindness and eventual euthanasia in most affected individuals. The disease has many similarities to Vogt Koyanagi Harada (VKH) disease in humans including panuveitis, vitiligo, and poliosis. The cause for UV syndrome is not known, but an immune-mediated etiology is strongly suspected with severe inflammatory infiltrates and loss of melanocytes in affected tissues. In a recent report, normal Akita dogs immunized with tyrosinase-related protein developed a disease closely resembling human VKH. Skin lesions in UV Akita dogs contained predominantly T lymphocytes and macrophages, while occular lesions contained mainly B lymphocytes and macrophages.