By bringing an animal onto your farm, you accept the reality that the animal could become sick and require veterinary attention. Most often, livestock feeling under the weather are inflicted with something ordinary, such as influenza, internal parasites or toxicity from something they ate. Every now and then, a serious disease can make its way onto your farm via another farm (by purchasing an animal from there or by visiting and bringing diseases back on your clothing), wildlife or unknown causes.
In the name of international livestock-health and human-health interests, your state agriculture department and the USDA Animal and Plant Health Inspection Service, in conjunction with the World Organisation for Animal Health, keep track of a list of diseases known as “reportable diseases” for cattle, pigs, sheep, goats, poultry, horses, rabbits, fish, bees and more. Some of these diseases are zoonotic—affecting both animals and humans. (APHIS reports that approximately 75 percent of recently emerging infectious diseases affecting humans are diseases of animal origin, and approximately 60 percent of all human pathogens are zoonotic.) Other diseases have been eradicated from certain areas of the country or the world and are being monitored to ensure they remain under control. If a reportable disease is found on your farm, you and your veterinarian have a legal obligation to notify the state veterinarian so control methods and proper reporting can be put into place.
The odds are good that you won’t have to deal with anything like these diseases in your animals, but here are five that infect multiple species—sometimes including people—that you should know about.
1. Anthrax
Where it’s found: Most common in tropical countries but also found in the U.S. It’s primarily found in alkaline soils with high nitrogen levels, and in temperatures above 60 degrees F. Anthrax spores may remain in the soil for 50 years.
How they get it: ingestion of the bacteria Bacillus anthracis from soil, air, contaminated feed or contact with dead animals infected with anthrax
Symptoms: staggering, convulsions, bleeding, high fever (107 degrees F is possible), death in a matter of days
Prevention: Vaccines are usually only administered in areas of high incidence.
2. Brucellosis (Brucellaabortus)
There are multiple species of Brucella bacteria, and three are reportable diseases. This information focuses on B. abortus.
AKA: contagious abortion, Bang’s disease
Where it’s found: Around the world; in the U.S., primarily around Yellowstone National Park, though as of November 2014, every state was accredited brucellosis free.
Who gets it: primarily cattle, bison and cervids; also humans
How they get it: Brucella abortus is a bacteria transmitted through contact with secretions (birthing fluids, milk, blood, urine, semen, et cetera) and mucous membranes (eyes, nose and mouth) of infected animals. It can be spread by objects—feed, equipment or boots, for example—and animals can act as carriers without showing symptoms.
Symptoms: Symptoms of this form of brucellosis are largely reproductive, including abortions and infertility. The disease can also cause recurring fevers, lameness, skin lesions and mastitis.
Prevention: B. abortus can live in an environment for long periods of time but can be killed when an area is cleaned and disinfected. There is a vaccination program for cattle and for wildlife in Yellowstone National Park so the disease cannot be spread to neighboring cattle herds.
3. Eastern Equine Encephalomyelitis
AKA: Sleeping sickness
Where it’s found: along the East Coast and Gulf Coast; in the upper Midwest U.S.
Who gets it: Humans, horses and birds How they get it: EEE is carried by birds and transmitted by mosquitoes. The disease cannot be spread from horses to humans.
Symptoms: Horses exhibit incoordination, erratic behavior, seizures and death. Humans might only show mild flu-like symptoms or become seriously infected and have a severe fever and headache followed by seizures, a coma, brain damage or death.
Prevention: A vaccine is available for horses but not for humans. Take steps to reduce mosquito populations and your risk of being bitten. Remove standing water around the farm, wear mosquito repellent and cover your skin during peak-mosquito times.
4. Johne’s Disease
AKA: Paratuberculosis
Where it’s found: worldwide
Who gets it: ruminants
How they get it: Infection with the Mycobacterium avium sub. paratuberculosis bacteria usually happens before birth or within the first year of an animal’s life by ingesting infected milk or manure. The bacteria can live up to a year in the environment.
Symptoms: weight loss, diarrhea, a soft swelling under the jaw—known as bottle jaw—and eventually death; signs don’t appear for about two years after infection.
Prevention: Test new ruminant livestock before bringing them to your farm. Reduce the risk of manure contamination of feed and water sources by keeping troughs and feeders clean and off the ground. Don’t allow animals into an area that’s been found to be infected with MAP bacteria within the past year. Read about the Voluntary Bovine Johne’s Disease Control Program.
5. Tuberculosis (Mycobacterium bovis)
There are three Tuberculosis strains. This information focuses on the bacteria M. bovis.
AKA: TB
Where it’s found: worldwide
Tuberculosis has been nearly eradicated in the U.S., thanks to tight disease monitoring and control. As of Nov. 2014, California and Michigan were the only states not accredited free of the disease.
Who gets it: warm-blooded animals, primarily cattle; humans (1.9 million people died from TB in 2013.)
How they get it: Bringing an infected animal onto the farm and contracting the disease from wildlife in contact with the herd are the most common ways TB is transmitted. Transmission is airborne, spread through bacteria from infected animals in feed and water, and contracted via drinking the raw milk of an infected animal.
Symptoms: Signs are not present in the early stages of TB. Later symptoms include emaciation, lethargy, weakness, anorexia, low-grade fever, enlarged lymph nodes and pneumonia with a chronic, moist cough.
Prevention: Have your herd tested, and only get new animals from herds tested free of TB. Limit your animals’ contact with wildlife, especially if wildlife in your area has been found to have TB. If visiting another farm, change boots and clothing, and require visitors from other farms to the same.
These are just a few diseases that are required to be reported to your state veterinarian’s office and, in turn, to the USDA and World Organisation for Animal Health. Check with your state veterinarian’s office for more diseases specific to your state.
