Dogs infected with B. suis can remain bright, alert and show no obvious signs of infection. Dogs can also display a range of signs with the most common including the following:

• Reproductive problems (abortions, still births, birthing problems, inflammation of the testes or epididymis)
• Back pain
• Lameness or swollen joints

Less common signs include

• Prostate inflammation
• Bloody urine
• Enlarged lymph nodes

Fever is not a consistent finding of brucellosis in dogs.

Brucellosis is a notifiable disease in NSW and If you suspect B. suis infection in a dog, you have a legal duty to notify your suspicion within one working day by calling the EAD Hotline on 1800 675 888 (24hrs) or your  Local Land Services Veterinarian on 1300 795 299, or contacting a NSW Department of Primary Industries and Regional Development veterinarian or regulatory officer or by emailing NSW DPIRD via animal.biosecurity@dpird.nsw.gov.au including a completed a notifiable pest and diseases reporting form PDF, 166.38 KB

You should consult your veterinarian if you think your dog has B. suis. Until infection (or otherwise) can be confirmed, you should undertake the following precautions to protect people and animals on your property:

• Keep infected dogs isolated, away from all other animals
• Avoid all unnecessary human contact with suspect dogs particularly by immunocompromised people, pregnant women and children, who at higher risk of disease.

When handling potentially infected animals or contaminated products, protective equipment including gloves, a mask and eye protection should be worn. A non-permeable dressing should be applied to any open wounds. Hands, arms and all potentially contaminated surfaces (including equipment used in the slaughter and butchery of feral pigs) should then be washed with soapy water.

Contact your Public Health Unit of their Local Health District on 1300 066 055 to report a potential human exposure to B. suis.

Your veterinarian will collect and submit blood samples for testing. Where available, the testicles, uterus, foetal and associated placental tissues, vaginal swabs and semen may also be tested. More information on diagnosis can be found in the Brucellosis Primefact: Guidelines for Veterinarians. PDF, 274.7 KB

A single definitive blood screening test is not available for B. suis. Unless the bacteria can be grown from tissue, the dog’s history, clinical signs and blood test results must all be considered. Blood tests will be reported as positive, inconclusive or negative. Dogs with inconclusive results may need to be retested in 3 weeks.

NSW DPIRD will pay the laboratory fees for testing of dogs suspected of B. suis infection Dogs that have been in contact with a confirmed positive case should be tested as well. These additional costs including ongoing monitoring are the responsibility of the dog owner.

B. suis is common in feral pigs. Infections in dogs most commonly occur in animals that have been pig-hunting and dogs that have been fed raw feral pig meat or offal. Dogs showing clinical signs can then spread infection to other dogs through direct contact with the animal or its body fluids, especially during mating and at the time of birth.

Many infected dogs recover without ever showing clinical signs. Some clinically infected dogs can shed bacteria intermittently and present an ongoing risk of spread. Brucella species can survive in the environment for months under ideal conditions (low temperature, high humidity and no sunlight).

To protect your dogs:

• Ensure any equipment, clothes and vehicles are appropriately cleaned after each hunt, while wearing protective gear (goggles, mask, and gloves), to prevent other family members and pets being exposed to the bodily fluids of feral pigs.
• Do not feed raw feral pig meat, bones, blood, offal, testicles or other reproductive organs.
• Do not breed from dogs suspected or known to be infected with B. suis.
• Practice safe pig hunting and do not allow dogs to play with or feed on animal carcasses.
• Wash dogs after each hunt – preferably wash dogs before leaving the hunting site, while wearing protective gear, and away from others.
• If dogs are wounded during a hunt, use protective gear while administering first aid (gently wash wounds with clean water and cover with dressings) and take the dog to a veterinarian.

More information on managing disease risk in dogs can be found in the NSW DPIRD Hunt safe, hunt legal: be a responsible pig dogger guide

In humans, Brucellosis typically causes a flu-like illness and may cause disease in the liver, spleen, airways and gut. Rarely, the heart valves may become infected which can be life-threatening. Testicular inflammation may occur in males. Pregnant women and their babies are at risk of severe disease with the potential for stillbirths and abortions resulting from untreated infections.

In Australia, feral pig hunters are at greatest risk of infection with B. suis. While infection usually follows direct contact with an infected feral pig, human infection directly from infected dogs has occurred when handling infected dogs around the time of birthing or lactating. Anyone who develops symptoms after contact with at-risk animals should contact their Public Health Unit of their Local Health District on 1300 066 055.

To reduce the risk of B. suis, you should:

• Promptly seek veterinary advice if you are concerned that your dog may be infected.
• Advise your veterinarian if your dog has been in contact with feral pigs, feral pig meat or infected dogs, so that they can take appropriate precautions when conducting veterinary procedures.
• Test at-risk dogs prior to breeding as dogs are most likely to be shedding the bacteria around the time of birth and lactation.
• Wear appropriate protective gear (goggles, mask, and gloves) when handling at risk animals, especially during mating and birthing.
• Ensure individuals with greatest risk of disease (immunocompromised, pregnant woman and children) avoid contact with at-risk animals.

For more information on human Brucellosis please see the NSW Health factsheet . Specific guidance for feral pig hunters can be found in the NSW Health factsheet “Brucellosis and feral pig hunting” . Contact your Public Health Unit of their Local Health District on 1300 066 055 to report a potential exposure and for further advice on managing the spread risk.

Management of Brucellosis in a dog

Infected dogs showing clinical signs may shed intermittently and present an ongoing risk of spread to other dogs and people. A treatment and management plan should be developed with your veterinarian.

This will likely include:

1. Treating AND desexing the infected dog.
2. Testing of at risk in-contact dogs.

Desexing of infected dogs is advised as infections in reproductive tissue or bone may not respond to antibiotic treatment.

Treatment includes a long course of antibiotic therapy. At the completion of the antibiotic course, the dog should be reassessed by your veterinarian. Some dogs may initially respond to treatment and then relapse (i.e. shows signs of illness of brucellosis in the future). If a treated dog relapses, the dog should be taken to a veterinarian as soon as possible for further assessment.

It is recommended that dogs that have had any contact with an infected dog are tested to check if they have been infected. In-contact dogs should be considered infectious until test results are returned. If an in-contact dog returns an inconclusive result, retesting may be conducted three weeks later.

Because of cost restraints or concerns that treatment may not have 100% efficacy, in some cases owners may opt to euthanise an infected dog.

More information on management can be found in the Brucellosis Primefact: Guidelines for Veterinarians. PDF, 274.7 KB

NSW DPIRD Procedure: Biosecurity – Brucellosis in Dogs: Biosecurity - Brucella Suis in dogs

NSW DPIRD Hunt safe, hunt legal: be a responsible pig dogger guide –  Be a responsible pig dogger

For more information on human Brucellosis please see the NSW Health factsheet at Brucellosis fact sheet

Specific guidance for feral pig hunters can be found in the NSW Health factsheet Brucellosis and feral pig hunting fact sheet

The time between infection and the appearance of symptoms can range from one week up to two months. Signs that a pig herd has become infected with Brucella suis are mainly those of reproductive failure – abortions, returns-to-service after mating and the birth of weak or stillborn piglets. Some sows may develop an infection of the uterus and show a vaginal discharge. Infected boars may develop swollen, inflamed testicles (see photo below). Pigs may become lame with swollen joints and/or develop signs of incoordination and hind leg paralysis.

Brucellosis (Brucella suis) is a notifiable disease in pigs and other animals under NSW legislation. This means there is a legal obligation to notify authorities if you know or suspect that an animal has this disease.

You can report suspected or confirmed brucellosis (Brucella suis) in animals in one of the following ways:

• Phone your Local Land Services on 1300 795 299; or
• Contact a NSW Department of Primary Industries and Regional Development veterinarian or authorised officer.

There is no direct serological test available for Brucella suis. However, Brucella abortus is exotic to Australia and this bacterium can be used as an antigen to detect Brucella suis. The Rose Bengal test (RBT) is the screening test in all species.

Positive and inconclusive results are subsequently tested with the confirmatory complement fixation test (CFT). Negative RBT results, but with a strong clinical picture and history suggestive of Brucella suis infection will also be tested with the CFT.

Domestic pigs in NSW will be re-tested in six weeks if both the RBT and CFT tests are inconclusive. The RBT is a more sensitive serological test compared to the CFT. The CFT is a more specific serological test compared to the RBT. Neither test is 100% accurate.

A diagnosis of porcine brucellosis in a domestic pig herd in NSW will not rely solely on laboratory serological tests. The clinical picture and history will also be important considerations. Brucella suis infection can be confirmed by bacterial culture from tissues or fluids e.g. testicle, semen.

Specimens required for laboratory testing include:

• Serum samples (not blood) submitted chilled for serology (RBT and CFT)
• Tissues or fluid submitted chilled for bacterial culture
• Aborted foetuses submitted whole for bacterial culture

Specimens should be sent to:

NSW Department of Primary Industries (DPI) Laboratory Services
Elizabeth Macarthur Agricultural Institute
Woodbridge Road, Menangle NSW 2568

A specimen submission form must accompany specimens submitted to the laboratory. The laboratory can be contacted on 1800 675 623 and laboratory.services@dpird.nsw.gov.au for further information.

The most likely method of entry of Brucella suis into a domestic pig herd is through contact with feral pigs. Good biosecurity is important to limit contact between feral and domestic pigs and includes building pig-proof perimeter fences.

Figure 2 Brucella suis infection pathways from a sick pig (in red). Note, the size of the arrow is related to the level of disease risk - in descending order: infected birth products, mating and artificial insemination, contaminated soil or bedding, contaminated

Local feral pig numbers can be controlled by trapping, shooting and/or baiting. Check with your Local Land Services (LLS) office on 1300 795 299 for advice on options to control feral pigs in your area or visit www.lls.nsw.gov.au.

Note: it is an offence to transport, keep or release live feral pigs, and any suspect behaviour should be reported to your local LLS office or the police.

Brucella suis is generally transmitted to pigs after ingestion of contaminated reproductive material – usually birth and/or abortion products and uterine discharges. Infection can also spread during natural mating or artificial insemination with infected semen. Brucella suis can circulate in the bloodstream of infected pigs for up to 90 days. Some pigs recover from infection, while others remain permanently infected. Boars that develop infections of the reproductive tract seldom recover.

Pigs can become infected with Brucella suis after eating contaminated feed, water, manure, wool, and hay. Brucella suis can also be spread on contaminated equipment and clothing. Under ideal conditions of low temperature, high humidity and no sunlight, Brucella suis can survive for several months in the environment.

Brucella suis can be transmitted to people. Feral pigs are the usual source of infection for people, particularly when there has been contact through breaks in the skin with the tissues and body fluids of an infected pig e.g. blood, urine, uterine discharges and aborted foetuses. Uncommonly, bacteria can be inhaled and cause disease, such as in laboratory workers who work with Brucella suis cultures. The infection is very rarely transmitted from person-to-person.

For more information call your local public health unit on 1300 066 055 or see the human brucellosis control guideline

Control and prevention

No vaccine is available for the control of Brucella suis infection in pigs.

Prevent feral pigs from contacting domestic pigs by erecting pig-proof fences and controlling local feral pig populations.