What is canine brucellosis?

Brucellosis in dogs is an infectious bacterial disease caused by the organism Brucella canis. Until very recently, it was nearly unheard of in the UK. In recent years, while still rare, it has been seen more frequently. This is due to greater numbers of dogs being imported from countries where brucellosis is endemic.

It is a serious concern, not only because of the symptoms but because there is a public health interest in keeping it contained.

What are the clinical signs of brucellosis?

Many animals infected with brucellosis will be asymptomatic. Brucellosis primarily affects the reproductive system in dogs and can cause a wide range of problems including decreased fertility, miscarriage and stillbirth, testicular swelling, and vaginal discharge.

It can also cause more generalised clinical signs of infection like lethargy, muscle weakness, weight loss, and swollen lymph nodes.

How is brucellosis transmitted?

Brucellosis is mainly transmitted through contact with the bodily fluids of infected dogs. The organism is concentrated in the reproductive tract, and therefore, contact with reproductive fluids is the most common source of infection.
Dog mating and whelping is the main mode of transmission, though it can also occur from close contact between dogs and (for example) incidental transfer of saliva.

How is brucellosis diagnosed?

If your vet suspects brucellosis based on your dog’s symptoms and clinical history, they may proceed to order tests that would detect antibodies for the Brucella bacteria in the blood or lateral flow tests to search for an active infection.

Diagnosis is challenging, however, and repeated blood testing may be necessary. Both false positive and false negative results are common, and only the culture of the organism is considered the definitive method for confirming infection.

Routine screening of dogs that have travelled abroad or have been imported is recommended, but a positive result in a dog with no clinical signs of infection does not confirm that infection is present.

Positive test results must be reported to the government body APHA (Animal and Plant Health Agency).

Image of a lethargic spaniel lying on the floor for Vets Now article

Can brucellosis be treated?

Brucellosis is difficult to treat. It is generally considered a chronic condition as it can be impossible to clear up with antibiotics. Dogs carrying the bacteria can continue to spread it to other dogs.

Due to the public health concerns around brucellosis spreading in the UK, if a dog is confirmed to be infected often the recommendation will be euthanasia.
Is brucellosis dangerous to humans?

In rare cases, brucellosis can be transmitted from dogs to humans. The risk to humans is considered low to very low. Veterinary professionals, immunocompromised individuals, and owners of infected dogs are considered to be within the highest risk group.

Veterinary professionals will use PPE where risk of infection is a concern. In humans, generally the clinical signs are milder than in dogs. The disease has not been shown to transmit between humans.

What can I do to prevent brucellosis?

Dog breeders should be aware of the brucellosis status of any dog they are working with. If you are considering adopting a dog from a country where brucellosis is common, you should engage with the rescue on how they test for the disease.

Again, brucellosis is still rare in the UK, but it can be serious. If you have a reason to suspect your dog may have been exposed to or is suffering from brucellosis, our Video Vets Now telehealth service can offer advice.