assistance dogs are a little known but crucial tool for children with autism .
they are used to keep the child safe and encourage social skills .
children with autism often have difficulty with social interactions and their verbal and non-verbal communication skills may be badly affected .
autistic children ` have a tendency to ` bolt ' when anxious or stressed .
the assistance dog is trained to keep a child out of harm 's way and make outings more manageable for the carer .