1, when your dog was vaccinated, did you have antibodies against canine distemper virus?
2. Is the dog with canine distemper out of the peak period of detoxification or half-life? This also determines the probability of infection.
3. The degree of contact between your dogs is licking each other, and whether the secretions cross into the body.
4. How is your dog's physique and immunity recently?
If you are afraid of infection, you can feed your dog some nutritional cream to improve your recent immunity, or go directly to the hospital to inject antiviral serum.
I hope I can help you, adopt the best answer and pay attention to yourself. I am a professional animal doctor.