Dandie Dinmont Terriers can be left alone for short periods, but they are generally social dogs who thrive on companionship. Dandies can be prone to separation anxiety if left alone for extended periods, especially if they are not accustomed to being alone. This can lead to destructive behavior or excessive barking. Establishing a consistent routine can help Dandies feel more secure when alone. Regular exercise and playtime before leaving them can also tire them out, making them more likely to relax while you’re away.