This happens due to two reasons :
1. If you set the Fur option to ON and geometry to low or medium, it happens because the basic textures of animal are loaded and then the fur is loaded when u come near to it because the geometry setting is on low or medium. Geometry setting handles the quality of the object that can be seen from where you are standing, you wont find this problem if you set geometry to very high or ultra but results in poor performance. However this "loading effect" can't be seen if you enable nvidia's fur enhanced version regardless of the geometry setting.
2. You can see the textures are being loaded multiple times like 3~4 times, regardless of geometry and fur settings because of a command called...