All pets can be aggressive, but this is especially true with older animals. Aging and more fragile animals may make up for their lack of strength by becoming over-aggressive. In addition, pets may become aggressive towards animals and people who invade their territory. Older pets are often less agile and may be fearful of losing their ground to another person or pet. If you are experiencing aggressive behavior in your older pet, be calm and reassuring, letting your pet know that it is not being threatened. Special care should be taken when introducing small children or animals to an aggressive pet, as its behavior can be unpredictable. You will want to minimize the risk of injury by avoiding situations which may be stressful or threatening to your older pet. For more information, contact your veterinarian or animal care specialist.