Sudden blood scabs on the cat’s neck may be caused by skin disease or trauma. You need to observe whether there is redness, swelling, dander, itching, etc. in the affected area of ​​the cat. If so, it is a skin disease. You can apply it to the affected area to treat the skin. If there are no other circumstances, it is caused by trauma. You only need to clean and disinfect the wound to avoid wound infection and inflammation.