A dog from a Romanian shelter and a dangerous bacterium: Swedish vets describe brucellosis in a dog whose back pain could not be treated, and warn of the risks of importing dogs

What happened

The scientific journal Acta Veterinaria Scandinavica has published a case report from Sweden, which the science news site Bioengineer covered on 7 November 2026. The vets describe a dog from Romania in which the bacterium Brucella canis caused severe damage to the spine. The authors believe it is the first documented case in Sweden in a dog that was not used for breeding.

A puppy from a Romanian shelter

The story began like many others. The puppy was found on the street in Romania, went to a shelter and then to Sweden, where a family adopted it. It was about five months old. Several other dogs lived in the same household, some of them from the same Romanian shelter.

Pain that kept coming back

In December 2023 the dog was taken to the Evidensia specialist animal hospital in Strömsholm. It was generally stiff, had abdominal pain, a fever and marked discomfort in its back and legs. A local practice had already treated it for a week with the antibiotic doxycycline and the painkiller robenacoxib. It improved, but the symptoms returned once the course was finished.

The first suspicion

On examination the vet found severe back pain, lethargy and slightly enlarged testicles. The combination of signs and the dog's origin in a region where brucellosis occurs led the vets to suspect Brucella canis. In dogs this bacterium affects the reproductive organs, the spine and other tissues.

What the tests showed

A urine culture grew no bacteria. But an antibody test carried out by a laboratory in the Netherlands was positive, with a titre of 1:150 against a cut-off of 1:100. Despite pain relief with pregabalin and robenacoxib, the severe pain continued. There is no effective treatment for canine brucellosis, and the owner decided to have the dog put to sleep.

What the post-mortem found

Pathologists found chronic inflammation in several parts of the prostate. The spleen and abdominal lymph nodes were enlarged. The most unusual finding was in the spine: between the first and second lumbar vertebrae there was a fully mineralised lesion two centimetres wide that could not be cut with a knife. The disc had been destroyed.

Final confirmation

Cultures from the prostate, testicles, lymph nodes and spleen again grew nothing. But PCR, a test for the organism's genetic material, confirmed Brucella canis. A second antibody test and a rapid test were also positive. Only the combination of all these methods gave a definite diagnosis.

Testing the other dogs

After the diagnosis the vets examined four dogs that had lived with the sick dog. Three came from the same Romanian shelter. None showed signs of illness. In January 2024 antibodies were found in one bitch, and by February all three were positive, with the bitch's titre rising from 1:200 to 1:500.

A difficult decision

Urine cultures and PCR in the contact dogs remained negative. Because of the rising titre, the bitch was nevertheless put to sleep and examined. Only mild lymph node inflammation was found, with no confirmation of the bacterium. The fourth dog, an adult bitch thought to be a littermate of the sick dog, was negative on every test.

How the infection spread

The authors think the contact dogs were probably infected through urine. Brucella canis is shed in urine intermittently and in small amounts, so infection requires long, close contact. The negative results in the fourth dog suggest it was probably not related to the sick dog at all.

Not the first case in Sweden

Sweden's history of canine brucellosis is short. The first case was described in 2011 in a bitch imported for breeding. The 2013 and 2018 cases were also linked to imported dogs or contact with them. The new case matters because it is the first described dog in Sweden that was not used for breeding, and the disease showed itself as damage to the spine.

What Brucella canis is

Brucella canis is a bacterium that in dogs most often causes infertility, abortion in bitches and inflammation of the testicles and prostate in males. Less often it affects the spine, eyes and joints. Many infected dogs look healthy for years but can shed the bacterium. The disease is hard to treat, and a full cure cannot be guaranteed.

Romania and dog imports

Romania is one of the main countries of origin for dogs brought into Sweden. According to the authors, it accounted for 32% of all imported dogs in 2024. Many are shelter dogs with unknown histories. There is no compulsory brucellosis testing of shelter dogs in Romania, so how common the infection is there is not really known.

A gap in the rules

Studies show that brucellosis is more common in stray and shelter dogs. In Sweden no brucellosis test is required when dogs are imported. The authors point out that some countries, such as the UK, have already tightened testing requirements for imported dogs. Swedish vets believe the gap needs to be discussed.

Why diagnosis is difficult

Diagnosing Brucella canis is one of the hardest tasks in canine medicine. The bacterium is shed intermittently, so cultures are often negative. Antibody tests can give false positives because of similar bacteria, and false negatives early in the disease. That is why vets use several methods together and repeat tests after a few weeks.

Risk to people

Brucella canis can be passed to people. In humans it causes vague symptoms: a fever that comes and goes, weakness and muscle aches. Human infections are rare but can be dangerous for people with weakened immunity, pregnant women and children. So if brucellosis is suspected in a dog, strict hygiene is important.

What happens to contact dogs

Decisions in these cases are ethically difficult. A dog with antibodies is considered exposed, but proving that it is infectious is hard. Experts recommend precautions:

1. Neuter entire males and females.
2. Do not use them for breeding or take them to shows.
3. Limit close contact with other dogs.
4. Protect people with weakened immunity from close contact.
5. Repeat tests regularly and watch for symptoms.

If you are adopting a dog from abroad

If you plan to adopt a dog from a shelter in another country, ask the organisation whether the animal has been tested for brucellosis and other diseases. Good organisations test before travel and share the results. This is especially important if you already have dogs, plan to breed or someone in your family has a weakened immune system.

What to check after arrival

Once the new dog has arrived, it is wise to see a vet in the first few weeks and discuss tests based on the country of origin. For dogs from eastern and southern Europe, vets often recommend testing not only for brucellosis but also for leishmaniosis, babesiosis, ehrlichiosis and heartworm. It costs money but protects both the new dog and the others.

No reason to turn away rescue dogs

A single case report is not a call to stop adopting dogs from Romania: most of these dogs live with their new families without similar problems. The point is for imports to be responsible, with testing, quarantine where there is doubt and honest information from the organisations that rehome dogs.

Hygiene if infection is suspected

If brucellosis is suspected in your dog, clear up urine and discharges wearing gloves, wash your hands after contact and do not let the dog lick your face. Pregnant women and people with chronic illnesses should be especially careful. If anyone in the household develops an unexplained fever, tell the doctor about the dog.

Back pain in a young dog

The Swedish case is a reminder that back pain in a young dog is not always caused by an injury or a slipped disc. Inflammation of a disc can be caused by infection. If the usual treatment only helps for a while, your vet may suggest X-rays, a CT scan and tests for infectious agents, taking the dog's origin into account.

What this means for Europe

Dogs move freely within the EU, and Romania remains one of the main countries from which dogs are rehomed to northern and western Europe. The Swedish case shows that without compulsory testing, brucellosis can enter countries where it was almost unknown without anyone noticing. That is an argument for common European rules on testing dogs rehomed across borders.

When to see a vet

See your vet if an imported dog develops back pain, is stiff getting up, is lame, has a fever, enlarged testicles or a discharge from the genitals, aborts or fails to become pregnant. Get help urgently if the dog refuses to move or cries out in pain. Always tell the vet which country and which shelter the dog came from.