Summary Tumours of vascular origin are uncommon in horses. This report describes the surgical treatment of a large subcutaneous tumour in a Quarter Horse colt. The histopathological appearance of the mass was most consistent with a haemangioma. While these neoplasms of vascular origin are often difficult to characterise, it has been suggested that there is a continuum of types with some cases falling between the categories. Further classification of vascular tumours requires special stains and immunohistochemical techniques.

Neuropathologic examination revealed axonal swelling and breakdown leading to Wallerian degeneration of affected myelinated nerve fibers in the spinal cord white matter of four young horses with equine cervical compressive myelopathy. Immunohistochemical reactions for the cell stress protein ubiquitin revealed an enhanced presence in the swollen axons, which may reflect a role for ubiquitin in the neuronal catabolic process of axonal compression and degeneration in this myelopathy.

CONGENITAL malpositions and deformities of the gallbladder are all relatively rare. The majority, however, are of such a nature that their presence is likely to lead to difficulty at operation, and, since diseases necessitating an investigation of the gall-bladder are common, it is important that attention should be directed towards them. One of the rarest of such lesions appears to be the presence of a gallbladder situated on the under surface of the left lobe of the liver-that is, to the left of the longitudinal fissure and the falciform ligament. It must not be confounded with a gallbladder displaced to the left owing to atrophy of the left lobe of the liver, such as has been recorded and figured by Rolleston.5 There, however, it will be seen that the gallbladder remains to the right of the falciform ligament.