tailieunhanh - Black's veterinary dictionary 21st edition - H

Từ điển thú y vần H | H H-Y Antigen This histocompatability antigen is present in the gonads of the bovine freemartin. It causes XX cells in the female gonad to assume testicular organisation. It is responsible for the rejection of male grafts by females of the same species. Habronemiasis Infection of horses with worms of the genus Habronema the cause of summer sores and a usually mild chronic gastritis. See ROUNDWORMS Horses. Haemangioma Haemangioma is a tumour composed of blood vessels. In the liver of adult cattle small haemangiomata are not uncommonly found but they are seldom of any practical importance. See also under GUTTURAL POUCH for haemangioma in horses. Haemangiosarcoma Cardiac A malignant tumour which may give rise to fatal internal haemorrhage and has been found in the lung spleen liver kidney brain etc. of dogs. Thirty-eight cases of this were seen at 1 veterinary hospital. In 16 dogs it was found on exploratory thoracotomy in 22 the diagnosis was made only at autopsy. In 9 dogs in which the tumour could be resected survival time averaged 4 months. Metastases were found in 16 of the dogs. Haematemesis Vomiting blood. When the blood is from a lesion of the stomach or oesophagus it is bright red but when it has lain in the stomach for some time and been partly digested it resembles coffee-grounds. Haematidrosis The presence of blood in the sweat. Haematocele A haematocele results when blood collects in a body cavity. It often refers to the testicle following an injury which has ruptured the smaller blood vessels. Blood from them then collects in the cavity of the scrotum in the loose fascia or in the outer coat of the testicle itself. Haematocrit Value The percentage by volume of whole blood that is composed of erythrocytes. It is determined by filling a graduated haematocrit tube with blood treated so that it will not clot and then centrifuging the tube until the red cells are packed in the lower end. As a rough guide values range as follows sheep 32 cow 40 horse and pig .