Anyone who has regular contact with animals should be aware of the risk of “zoonotic” diseases – those which can be spread from animals to humans. Fortunately many of these diseases are uncommon. There are some well-known examples which can be caught from livestock (such as leptospirosis or Q fever), but feral animals or wildlife can also pose a risk.

Recently, there’s been quite a bit of media coverage of brucellosis caused by the Brucella suis bacteria. We know from research in Queensland and North West NSW that Brucella suis is carried by some feral pigs.

It’s important to note that this is not the same brucellosis that was eradicated from the Australian cattle herd in the late 80s (through the successful Brucellosis and Tuberculosis Eradication Campaign). Bovine brucellosis has not been detected in Australia since that time. Brucella suis is also different to Ovine Brucellosis, which affects fertility in rams. Brucellosis in sheep has negative effects on production, but cannot be spread to humans.

In contrast, Brucella suis can be spread from pigs to humans, or to dogs. Often, people become infected when hunting and/or butchering feral pigs. Dogs are often infected following involvement in pig hunting, or if they’re fed raw feral pig meat.

In humans, Brucella suis can cause severe flu-like symptoms including fever, lethargy, headaches, and joint or muscle pain.

In dogs, Brucella suis can cause fever, lethargy, abortion, enlarged testicles, lameness, or back pain. However, symptoms are very variable, can be non-specific, and some dogs may show no symptoms at all. Just because your pig hunting dog doesn’t look obviously unwell, this doesn’t mean it isn’t carrying a Brucella suis infection. Vets have found Brucella suis cases in dogs which looked perfectly healthy.

One reason this is important is that it’s possible humans could also be infected through exposure to infected dogs. Brucella suis is an emerging disease and we don’t yet fully understand all the risk factors. 

Vets treating dogs that have been exposed to feral pigs need to consider the possibility of Brucella suis.

If you’re a dog owner and are concerned about Brucella suis in your dog, your private vet can perform a blood test to check for the infection. In some cases a testing subsidy may be available.

Anyone involved in pig hunting should ensure good hygiene at all times, including proper use of personal protective equipment. 

Eating undercooked feral pig meat should also be avoided. 

More information is available in the NSW Health Brucellosis Factsheet.