Dogs are by far the animal most commonly used to help humans, whether used as guide dogs for the seeing impaired, assistance dogs for people with other disabilities or service dogs used by the police and fire services.

But just what dogs must legally be allowed into a business, and which ones aren’t, is a question that plagues business owners across the UK.

With a confusing lack of guidance, many businesses have opted to not challenge any dog entering a business for fear of being in violation of the law.

However, allowing untrained dogs into a premises endangers the legitimate guide dogs whose handlers need them to accompany them into businesses.

One of the biggest causes of confusion are so-called “Emotional Support Animals,” a concept imported from the United States with no legal status or reason in the UK.

Harris Dickenson, of Disability Interest Groups (DIGS) in Salisbury, said: “In America, the definition of emotional support animals was created specifically for the Fair Housing Act and we don’t have that here; it as a result doesn’t carry over.

Harris said: “I think people are using it as just a pet they can take places, not realising the specific separation of what an assistance dog is.”

In the United Kingdom, laws have changed within the past two years which prohibit landlords and letting agencies from setting blanket bans on pet ownership in properties. Although these clauses often still exist in contracts (many of which are templates drafted before the law was changed) they are not enforceable.

Harris has been trying to raise awareness about the dilemma faced by businesses, the problems it causes and the overall confusion of which dogs must be allowed into establishments. It is a problem seen not only in Salisbury but across Britain.

Harris said: “It’s not as black and white as people think it is. A lot of people assume that there’s a registry or there’s mandatory certification required when there isn’t, so then also that opens it up to a lot of abuse, and that’s where you get issues with people just bringing in their pets and labelling them as emotional support animals.”

Harris said there have been multiple times places have tried to refuse them entry because they did not have registration documents for their assistance dog (which are not required and do not officially exist).

In the absence of official certification, Harris said the main litmus test that businesses need to follow when assessing whether to admit certain dogs, is the behaviour of the animal.

Harris said: “The really important bit is they need that good behaviour, and they need to not be a danger to the public.

“It is entirely down to the business to go ‘We’re going to let you in, but if your dog starts causing problems, regardless of who’s trained it, we will then have to ask you to leave.’”

The Equality and Human Rights Commission published a guide in 2017 informing businesses of the rules.