What is canine brucellosis? Dog disease found to be spreading in UK for first time - with three people also infected

A dangerous bacterial infection has been found spreading in the UK's dog population for the first time - but the disease has also been transmitted to three people

A new government risk assessment updated on Monday (18 September) found 97 dogs had tested positive for the Brucella canis bacteria in the year to June, largely linked to pets brought in from overseas.

However, it also revealed rather than just imported dogs testing positive, a number of UK dogs had as well. The Express reports this is the first time the disease has ever been recorded spreading domestically.

The bacteria, which can cause infertility in dogs, has also been discovered in two humans so far this year - making three total cases of people becoming infected in the UK.

But what is the risk of a person picking up Brucella canis, and how safe are dogs at home?

Here's everything you need to know.

How is the Brucella canis bacteria affecting dogs in the UK?

The number of dogs who have tested positive for the Brucella canis bacteria has been steadily rising since 2020 - largely linked to pets being brought in from overseas.

A Defra - or Department for Environment, Food & Rural Affairs - spokesperson told NationalWorld all UK cases have been in dogs that have either been imported, have mated with an imported dog, have had contact with the "birthing products" of an imported dog - or are the puppies of an imported dog.

The UK's chief veterinary officer, Dr Christine Middlemiss, said: “We take the risks posed by Brucella canis very seriously and require all cases to be reported to the Animal Plant Health Agency. This allows us to monitor the number of confirmed cases and keep risk assessments updated.

“We continue to work closely with our colleagues at [the UK Health Security Agency], dog welfare groups and vets to minimise the risks posed and recommend prospective owners make sure any dog imported from regions where Brucella canis is present is tested before arrival.” 

The disease is frequently sexually transmitted between dogs, and can affect the reproductive organs - even causing infertility or spontaneous abortions. The disease can move to other tissues, including the eyes, kidneys, heart or brain, and once infected, a dog is typically considered infected for life.

The majority of cases have been linked to dogs imported into the UK from Eastern Europe, and Defra is urging prospective owners to consider rehoming from a reputable organisation in the United Kingdom rather than importing pets from abroad.

"Those choosing to import pets from abroad should do so responsibly by ensuring they purchase from a reputable seller or breeder and that it is transported by an authorised transporter," they said.

"If considering importing a dog into the UK (or rescuing a dog that has been imported) we recommend prospective owners ensure testing for other diseases including Brucella canis is carried out before the movement takes place."

Can it be cured?

A Brucella infection in dogs is considered very difficult to treat, and may never be fully cured. In the US, where the disease is more widespread, the Minnesota Department of Health says treatment can include spaying or neutering the animal, giving it antibiotics for several months, and frequent blood tests to monitor treatment progress.

Even then, relapses are common, and the dog's quality of life may suffer. Treatment is usually only attempted in circumstances where the dog can be completely isolated from other dogs - potentially for the rest of its life.

In the UK, euthanasia is currently the only option recommended by the government. In part, this is to stop the disease spreading more widely.

Can it be spread to humans?

Yes. The UK Health Security Agency (UKHSA) says there have been three cases of humans becoming infected with Brucella canis since 2022.

The first, a woman from Stoke-on-Trent who caught it from a pregnant rescue dog from Belarus last August, was reported by the BBC at the time. All five of her dogs had to be put down.

Of the two more recent cases, one was picked up when a patient with symptoms arrived at hospital, and the other was a worker at a vet centre.

In a statement sent to NationalWorld, UKHSA's head of emerging infections and zoonoses Wendi Shepherd said: “Brucella canis is an infection carried by dogs that can be transmitted to humans.

"We have seen a small number of cases of Brucella canis in people in the UK this year," she continued. "However, the risk to the general public in the UK is very low and the risk to people who have had close contact with an infected dog is low."

From cases reported worldwide, a Brucella canis infection is usually mild in humans, the UKHSA said. "But people who have weakened immune systems, are pregnant, or are young children may be more likely to experience more serious infection.”

The NHS says the disease caused by Brucella strains of bacteria is called brucellosis - with the dog variant known as canine brucellosis. It can be picked up from animal's bodily fluids, but this is very rare.

It causes flu-like symptoms in humans, which can either appear suddenly or over the course of two weeks. These include a high temperature, loss of appetite, sweating, headaches, extreme tiredness, and back or joint pain.

There is no vaccine to prevent the disease, but it can be cured with a course of antibiotics.