Brucellosis – What You Need to Know to Protect Yourself, Your Family, and Your 

Employees

Brucellosis, also known an undulant fever, is an infectious disease caused by bacteria. People can 

get the disease when they have contact with infected animals or raw animal products. Brucellosis 

is not usually fatal to people, but may result in long-term illness and lasting health problems even 

after treatment. 

Infected animals that can put people at risk include:

• Pigs – Swine brucellosis was eliminated from domestic, commercial pigs in 2011. It is 

still present in the feral swine population. As a result, domestic pigs with outdoor access 

can still become infected from contact with infected feral swine. People most often 

become infected by helping an infected pig farrow (give birth). 

• Cattle – Brucellosis in U.S. cattle is rare, however, cases continue to occur in places 

where infected wildlife can spread the disease to cattle, such as the Greater Yellowstone 

Area. People are most often exposed when helping with calving, due to exposure from 

infected blood or tissues. Exposure can also occur from drinking raw milk from infected 

cattle. 

• Wild pigs (feral swine) – People can become infected through field dressing, handling 

raw meat, and exposure to blood from infected wild pigs.

• Elk, bison, deer, moose, and caribou – Exposure routes for people are similar to those 

for wild pigs. 

• Bears, wolves, coyotes and red fox – Animals that feed on infected wildlife may 

become infected. People can become infected through field dressing the carcasses of 

these animals.

• Dogs – Dogs can become infected by breeding with an infected dog or by eating infected 

animals or birthing products. An infected dog can spread the infection through the 

birthing process. People can be exposed by helping an infected dog give birth, and 

through contact with urine and other bodily fluids from infected dogs. 

Symptoms of brucellosis infection in people include:

• Fever – may come and go (undulate)

• Chills

• Headache

• Poor appetite

• Fatigue

• Pain in joints and/or muscles

• Weakness

Men can have swelling and pain in the testicles and prostatitis, and infection can cause women to 

have miscarriages. Untreated infections can lead to liver, heart, brain, and joint damage, and 

infertility. 

Animal and Plant

Health Inspection 

Service
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Protect yourself

Tips for hunters – see the Centers for Disease Control and Prevention Fact Sheet, Hunters: 

Protect Yourself from Brucellosis

Dog breeders:

• Insist that both male and female dogs are tested for brucellosis before breeding. Your 

veterinarian can take a blood sample from dogs and conduct a rapid test to screen for the 

disease. Your veterinarian should send the blood sample to a diagnostic laboratory for 

confirmatory testing. 

• If testing was not done prior to breeding, wear latex or other impermeable gloves, eye 

protection, and an N95 rated or higher disposable face mask when helping a dog give 

birth. These face masks can also be referred to as a particulate face mask and should be 

fit tested to ensure that they properly protect the user. The masks are available in home 

improvement stores. 

• For more information, see Brucellosis and Dog Kennels: What Breeders Need to

Know

Pig breeders (pigs with outdoor access): 

• Purchase or borrow breeding animals only from Validated brucellosis-free herds. Contact 

your local USDA APHIS Veterinary Services office for more information on becoming a 

Validated brucellosis-free herd.

• If you buy from a herd that is not Validated brucellosis-free, insist that all breeding 

animals in the herd of origin over 6 months of age are negative for brucellosis. This test 

should be done within 30 days before purchasing/borrowing any swine from the herd to 

your farm. The tests are good at finding infection in a group of animals, but do not work 

well on single animals and can miss infection. 

• Keep your pigs away from feral swine by using double fencing and keeping fences in 

good repair. Check fences daily. If you see feral swine or evidence of feral swine 

(footprints, rubs on trees, droppings) contact your State veterinarian’s office or USDA 

APHIS VS. 

• Wear full-length disposable poly sleeves, eye protection, and N95 rated or higher 

disposable face masks (also called a particulate facemask) when helping sows give birth 

(farrow). Don’t reuse face masks and remember to disinfect eye protection after helping 

with farrowing (with disinfecting wipes, diluted bleach solution, or other disinfectants 

labeled for killing bacteria).

• Wear latex or other impermeable gloves when handling piglets or aborted piglets.

• Dispose of dead piglets and fetuses by burial or off-site rendering/incineration to prevent 

spreading infection (for example, spread by scavenging predator animals). Check with 

your State Veterinarian’s office to find out which methods are allowed in your state.

• Purchase feeder pigs from commercial herds, or from brucellosis test-negative herds 

(Validated brucellosis-free herds are tested negative at least every 10-12 months).

• Wash your hands with antibacterial soap and water after working with pigs.

• Shower and change your clothes after helping with farrowing or working with pigs. Wash 

and dry your clothes as soon as possible.
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Cattle breeders:

• In areas where wildlife are infected, contact your local wildlife control agency or USDA 

APHIS Wildlife Services for more information on keeping wildlife away from your 

cattle. 

• Cattle can become infected by contact with infected feral pigs. Keep feral pigs out of 

your cattle pastures by double fencing, keeping fences in good repair, and walking fence 

lines daily. 

• In areas with infected wildlife or feral pigs, protect yourself from infection when helping 

a cow give birth. Protect yourself using similar safety steps as outlined for Pig Producers 

(protective clothing, showering, disposing of dead animals, etc.)

How to disinfect non-food surfaces, goggles, equipment:

• Clean off all organic matter (manure, dirt, etc.) then wash with a detergent if the item can 

get wet. This helps to remove all the organic matter.

• Use a disinfectant, prepared according to the label, which says it is effective against 

bacteria. 

• A bleach solution is a good disinfectant for surfaces that won’t be harmed by bleach. Mix 

1 part bleach to 4 parts water [e.g. 1 cup (236 ml) regular bleach to 4 cups (946 ml) of 

water]. At this dilution, you will have to make up a new solution once a week as the 

bleach become less effective over time. Bleach doesn’t work to disinfect surfaces that 

have organic matter, such as manure or mud on them. Be sure to clean surfaces well and 

wash them with detergent before applying the bleach solution. 

• Follow the label instructions for how long the disinfectant has to sit (contact time).When 

the contact time is up, rinse and dry the disinfected surface. For a bleach solution, contact 

time is at least 10 minutes before rinsing or wiping dry.

*Disposable face masks (N95 or higher) come in many shapes and sizes. One manufacturer’s 

mask will fit differently than another’s. A face mask can't protect you if it doesn't fit your face. If 

the mask doesn’t form a tight seal with your face, contaminated air can leak in the mask. For full 

protection, you should be “fit tested” to find out which mask best fits your face. Contact your 

local health department for information on where to get fit tested.

For more information:

Facts About Brucellosis 

https://www.aphis.usda.gov/animal_health/animal_diseases/brucellosis/downloads/bruc-facts.pdf

Brucellosis in Bison

https://www.aphis.usda.gov/animal_health/animal_dis_spec/cattle/downloads/cattle-bison.pdf

Brucellosis

https://www.cdc.gov/brucellosis/

Fit Testing a Disposable Respirator

https://www.cdc.gov/niosh/npptl/topics/respirators/disp_part/respsource3fittest.html