Introducing a new pet to your household can be a challenging situation, especially if your boxer is showing signs of aggression. Here are some steps you can take to help manage this behavior:

1. **Supervised Introductions**: Always supervise the initial meetings between your boxer and the new pet. This will help you intervene if necessary and prevent any aggressive encounters. Use a leash for your boxer during these introductions to maintain control.

2. **Gradual Introduction**: Start with short and controlled introductions. Allow them to see and smell each other from a distance before bringing them closer. Gradually increase their time together as they become more comfortable with each other.

3. **Positive Reinforcement**: Reward your boxer with treats and praise for calm behavior around the new pet. This encourages them to associate the new pet with positive experiences. For example, if your boxer remains calm while the new pet is nearby, give them a treat and lots of affection.

4. **Create Safe Spaces**: Ensure both pets have their own safe spaces where they can retreat if they feel overwhelmed. This could be separate rooms or designated areas where they can relax without feeling threatened.

5. **Training Sessions**: Consider enrolling your boxer in obedience training classes. A professional trainer can provide you with techniques to manage aggression and improve your boxer's socialization skills. Basic commands like 'sit', 'stay', and 'leave it' can be very helpful in controlling their behavior.

6. **Desensitization**: Gradually desensitize your boxer to the presence of the new pet. Start by allowing them to observe the new pet from a distance and gradually decrease that distance over time as they become more comfortable.

7. **Consult a Professional**: If aggression persists or escalates, consider consulting a professional dog behaviorist or trainer who specializes in aggression. They can provide tailored strategies to help your boxer adjust to the new pet safely.

Remember, patience and consistency are key. Every dog is different, and it may take time for your boxer to accept the new pet. With the right approach, they can learn to coexist peacefully.

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Topics covered in this question:

Dog Training Boxer Behavior Boxer Care Pet Introductions Aggression Management