We have a 1 year old Cattle dog/Australian shepherd mix.
he is NOT friendly with strangers.
and he takes his job, protecting our property and family, very seriously.
I wonder if he'd have to pass some sort of "friendliness" test with strangers?
No "friendliness test" as the onus is on you to control an aggressive dog
at all times or in England or Wales you can be fined and sent to prison and the dog destroyed.
England and Wales have some strict laws for dog aggression and the dog doesn't have to bite to be classed as dangerous. As you know he is aggressive it might be best to walk him with a lead and muzzle so that nobody is afraid they will get bitten when they pass you; this will also keep your dog safe.
The same law applies in your own home too, or in a neighbours home and on any private property: the owner must make sure they have full control of their dog at all times. As you already know your young dog shows aggression, you will need to be aware of this. Maybe even get one to one help with a dog behaviourist too while your dog is still young?
This is one instance where size doesn't matter as it applies to all dogs.
If your dog is aggressive in England or Wales -
Overview
It’s against the law to let a dog be dangerously out of control anywhere, such as:
in a public place
in a private place, eg a neighbour’s house or garden
in the owner’s home
The law applies to all dogs.
Out of control
Your dog is considered dangerously out of control if it:
injures someone
makes someone worried that it might injure them
A court could also decide that your dog is dangerously out of control if either of the following apply:
it attacks someone’s animal
the owner of an animal thinks they could be injured if they tried to stop your dog attacking their animal
A farmer is allowed to kill your dog if it’s worrying their livestock.
Penalties
You can get an unlimited fine or be sent to prison for up to 6 months (or both) if your dog is dangerously out of control. You may not be allowed to own a dog in the future and your dog may be destroyed.
If you let your dog injure someone you can be sent to prison for up to 5 years or fined (or both). If you deliberately use your dog to injure someone you could be charged with ‘malicious wounding’.
If you allow your dog to kill someone you can be sent to prison for up to 14 years or get an unlimited fine (or both).
If you allow your dog to injure an assistance dog (eg a guide dog) you can be sent to prison for up to 3 years or fined (or both).
https://www.gov.uk/control-dog-public/overview
