Dreams involving animals, particularly dogs, often symbolize loyalty, protection, and companionship. In your dream, the presence of your brother and the dogs may reflect your current feelings about your relationship with him.

Your old and injured dog could represent your own feelings of vulnerability or emotional wounds, possibly mirroring the resentments you have towards your brother. The idea of wanting to warm your dog with a blanket suggests a desire to nurture and heal, which may indicate your wish to mend the relationship with your brother.

On the other hand, your brother's dog, which appears healthy and content, might symbolize the aspects of your brother that you admire or the ideal relationship you wish to achieve.

Overall, this dream seems to highlight your internal conflict about your relationship with your brother and your need for healing and warmth, both for yourself and in your interactions with him. Consider reflecting on what steps you might take to address the resentments you feel and how you can move towards a more positive relationship.