实验动物学总论课件.ppt

Signs of Illness and Injury: Picking up mice. When picking up mice, always hold the mouse by the base of the tail. This can be done with either forceps or your fingers. DO NOT pick mice up by the tip of the tail. If you pick a mouse up by the tip of its tail, the mouse may spin in tight circles when its feet lose contact with the cage surface. If this happens, the tip of tail can be pulled off. Additionally, a mouse held by the tip of its tail can climb up its tail and bite you! Separating mice/rats by gender. Separating mice/rats by gender can be difficult, especially when they are young and males testicles have not descended into the scrotum. Compare the relative distance between anus and urinary papilla. The distance between the anus and the urinary papilla is greater in the male. This photograph illustrates that the mouse on the right has the lesser (shorter) distance between the anus and the urinary papilla, so it is the female. Restraining Rats. Rats can be caught and lifted by the base of their tail, or you can grasp them around their body as illustrated in this photograph. If you grasp the rat around its body you can prevent it from biting you by placing your index finger snugly under the jaw against the point of the shoulder ahead of the right front leg. Your thumb is placed behind the left front leg which pushes it forward against the left side of the neck. This grip secures the head, and the rat cannot reach around to bite. For large rats, keeping a good grasp on the tail will give you additional control. Guinea Pigs. Guinea Pigs have no tail and must be caught by grasping them around their body. They are very inclined to avoid being caught by scurrying around the cage and whistling loudly. When they are caught they rarely attempt to bite but may reach forward with their hind feet and scratch with their long toe nails. ??????????????????????????????????? Rabbits. Rabbits are characterized by their thin bones, fragile skeleton, and heavy mu