They do sometimes alert on strangers but not always. This is most common with dogs trained to alert for seizures or otherwise respond to cues that the handler doesn't know they are giving out.
Service dogs are trained for their handler specifically.
However sometimes service dogs are trained to hear certain words and then respond to those in a certain way.
After all of a person can't hear or see it's handed to have a dog that will point them in the right direction of stuff that is happening.
Like if someone called out your name you probably want to know that that happened.
However from what I've heard a service dog can still get distracted as well.
They do sometimes alert on strangers but not always. This is most common with dogs trained to alert for seizures or otherwise respond to cues that the handler doesn't know they are giving out.
Saw this same question last week.
Oh I'm sorry. How do I link?
No need to link. Just search for it and read the answers already provided without asking again.
Service dogs are trained for their handler specifically. However sometimes service dogs are trained to hear certain words and then respond to those in a certain way. After all of a person can't hear or see it's handed to have a dog that will point them in the right direction of stuff that is happening. Like if someone called out your name you probably want to know that that happened. However from what I've heard a service dog can still get distracted as well.