Ensure their environment is safe - comfortable bedding, toy options, minimal loud noises to avoid triggering.
Safety
Go slow when interacting to rebuild trust. Sit calmly, toss treats, letting them approach you first.
Patience
Create set schedules for feeding, walks etc so they can start expecting/relying on care routines.
Routine
Use reward-based training focused on confidence building tricks and cues to empower them.
Training
Gradually socialize with calm friendly dogs so they learn positive interactions.
Socialization
Provide interactive toys to help mentally/physically stimulate in safe ways.
Toys
Daily walks and play gives healthy outlets for energy and stress relief.
Exercise