Brucella canis in dogs

Dog relaxing on sofa

Recently, the UK’s seen an increase in the number of dogs affected by Brucella canis, but what is it, is there a test and can it spread to humans? Find out everything you need to know, including what to do if you suspect your dog is affected, in our article below. 

What is Brucella canis?

Brucella canis is a rare type of bacteria that can cause an incurable infection in dogs. It can be sexually transmitted during mating or can be passed on through contact with infected body fluids. An infection from Brucella canis, known as brucellosis, can lead to infertility, issues during pregnancy, genital problems, lameness and back pain. This bacterium can infect humans, but only a small number of cases have ever been reported.

In very rare circumstances, this bacterium has been passed on to humans from infected dogs, but it’s not a common problem.

Is Brucella canis common in the UK?

In the UK, infections with Brucella canis are extremely uncommon. The small number of dogs that have been infected are usually imported dogs. Even though you’re currently unlikely to meet an infected dog, the number of reported incidents are growing. Before 2020, Public Health England had been alerted to only two cases of infection, but these numbers increased to 40 within eighteen months.

Countries that have Brucella canis

Brucella canis is known to occur in the Americas, parts of Asia, Africa and eastern or central Europe. In the UK, most of the recently reported cases were from dogs that were rescued from eastern Europe, particularly Romania. This may not be because the rates of infection are higher in these countries but may be due to the number of dogs that have come from there.

How do dogs get Brucella canis?

Brucella canis can be passed on from infected dogs:

  • During mating
  • From contact with vaginal fluid, semen, pro-oestral blood and afterbirth
  • From mother to puppies during pregnancy and through her milk
  • Through contact with infected blood
  • Through contact with infected faeces, urine, saliva and nasal discharge. These materials contain less of the infectious bacteria and so have a lower risk of causing infection

The more time a dog spends with an infected dog or around infected body fluids and material, the more likely they are to become infected.

Do some infected dogs have a higher risk of passing on Brucella canis?

Some dogs with Brucella canis may be more infectious than others, including non-neutered adults, dogs that are sexually active and dogs that show signs of an infection.

What are the symptoms of Brucella canis?

Not all infected dogs show signs of infection, but in some, it can cause infertility, miscarriage, tiredness, lameness and back pain. In males, it can cause their testicles to become painful, swollen or they may develop a rash.

Can Brucella canis be treated?

Unfortunately, there are no guaranteed cures for Brucella canis. Affected dogs are infected for life. Even if a dog with Brucella canis doesn’t show any signs, it can still pass on the bacteria to other dogs. Neutering an infected dog can reduce the risk of spreading the disease. However, the only way to completely prevent passing on brucellosis is for infected dogs to be put to sleep.

Antibiotics have been used to protect veterinary staff from getting infected by infected dogs but antibiotics are not considered to help in any way in the treatment of the dog. Infected dogs must be kept away from other dogs, as well as other places that dogs visit, for the rest of their life.

Testing dogs for canine brucellosis

There are a number of different ways to test for canine brucellosis. If you’re concerned that your dog may be infected, your vet will be able to arrange a test for you. Not all tests can be carried out straight away and you may have to wait for several months after your dog was possibly exposed.

If your dog tests positive for Brucella canis then, by law, the Animal and Plant Health Agency must be contacted and told about your dog’s infection.

Can humans get Brucella canis?

Humans can be infected by Brucella canis but reported cases of infection are very rare. People who are in contact with infected bodily fluids are more at risk, including dog breeders (or anyone who helps with the birth or cleaning up the whelping box), vets, vet nurses and veterinary laboratory staff. People who have a weakened immune system, such as young children, pregnant women or people who are immunocompromised may be at a higher risk.

What’s the highest risk to humans?

The highest risk to humans is contact with an infected dog that’s given birth or had a miscarriage. Birthing fluids, vaginal fluids, afterbirth etc. all hold large amounts of the Brucella canis bacteria. Humans can become infected if bacteria from these fluids come into contact with a human’s mouth, eye or damaged skin.

Healthy pet owners who do not come into contact with the most infectious types of body fluids (vaginal fluid etc.) are thought to be at a lower risk than breeders.

Vets, veterinary nurses and veterinary laboratory staff can breathe in infectious aerosols from certain veterinary and laboratory procedures that involve infected dogs. Appropriate PPE should always be worn with infected dogs or samples from infected dogs.

What are the symptoms of Brucella canis in humans?

Humans are usually affected by Brucella canis in a different way than dogs and effects are often non-specific and less severe. Symptoms often start within three to four weeks of exposure (sometimes as early as one week and sometimes as late as six months). Effects can include:
  • Fever
  • Not seeming hungry
  • Weight loss
  • Sweating
  • Headaches
  • Tiredness
  • Back and joint pain

If you’ve been in contact with an infected dog and are concerned that you have been infected, speak to your GP for advice.

Think your dog may be affected?

If you're worried about your dog's health, always contact your vet immediately!

We are not a veterinary organisation and so we can't give veterinary advice, but if you're worried about any of the issues raised in this article, please contact your local vet practice for further information

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