Nigropallidal encephalomalacia in horses grazing Rhaponticum repens (creeping knapweed)

Nigropallidal encephalomalacia was diagnosed in two horses in northern Victoria that had a history of long-term pasture access to a dense growth of Rhaponticum repens. The region in which the affected horses lived had received well above average rainfall for several months preceding the poisoning. Affected horses had sudden onset of subcutaneous oedema of the head, impaired prehension and mastication, dullness, lethargy and repeated chewing-like jaw movements. Diagnosis was confirmed at necropsy, with characteristic malacic lesions in the substantia nigra and globus pallidus of the brain. This is the first documented case of nigropallidal encephalomalacia in Australian horses associated with R. repens.     

Focal symmetrical encephalomalacia in young calves

Three cases of focal symmetrical encephalomalacia diagnosed in calves Diffuse fibrosing alveolitis diagnosed in an adult cow Review of abortion in sheep Erysipelas septicaemia in outdoor-reared piglets Fine sawdust bedding associated with pneumonia in layer chicks These are among matters discussed in the disease surveillance report for May from SAC Consulting: Veterinary Services (SAC C VS).     

A focal symmetrical encephalomalacia of lambs

Extract

This paper was prompted by the observation of a wide variety of neurological signs in a number of young lambs, the brains of which showed a similar distribution of malacie lesions.     

Seizures in the horse

This article discusses the diagnosis and treatment of extracranial, intracranial, and idiopathic seizures.     

Focal symmetrical encephalomalacia in a 6-month-old Dorset sheep.

Neurological examination of a sheep that had acute onset of recumbency and mental depression indicated a diffuse symmetrical thalamocortical lesion. Cerebrospinal fluid analysis suggested a degenerative central nervous system disease. Thiamin administration resulted in partial and temporary improvement. Brain histological lesions were typical of focal symmetrical encephalomalacia.     

Monorchidism in the horse

Six horses with monorchidism, identified at surgery for cryptorchidectomy, are reported. All six presented with a single scrotal testis. Following surgical removal of one testis, they were either hormonally, anatomically or behaviourally determined to be geldings. Three other horses reported in the literature are reviewed. Of these nine cases of monorchidism, eight were thought to be caused by testicular degeneration and one by testicular agenesis. The vaginal process was present in all of the former and absent in the latter. The left side was involved in five of these eight horses. In seven, the epididymis was absent and, in the remaining two, only the epididymal tail was present. The condition was thought to be congenital in the six horses in this series. A surgical approach to identify accurately monorchid horses is described.     

Haemangiosarcoma in the horse

Neoplasms arising from vascular endothelial cells include benign haemangioma and malignant haemangiosarcoma, both of which are rare in the horse. Haemangiosarcoma can arise as a solitary mass, typically involving the eye or skin, or as disseminated tumours throughout multiple organs. There is no sex, breed or age predilection but most cases are found in middle aged horses. Clinical presentations of haemangiosarcoma in the horse include the presence of a visible mass or reflect dysfunction of the organ involved, thus making it difficult to differentiate from other neoplasms. Ante mortem diagnosis through clinicopathological findings, cytological findings of body cavity effusions or fine needle aspirates are often unrewarding. Biopsy or mass submission for histopathological examination may aid in diagnosis of haemangiosarcoma. A majority of cases are diagnosed post mortem; however, if the mass is poorly differentiated additional diagnostics such as immunohistochemical staining may be needed. Unfortunately, treatment of haemangiosarcoma is often unrewarding and limited based on the location of the mass and the aggressive nature of this neoplasm.