Disease prominent during drier years after pastures have flooded and spores are stirred to the surface
As livestock producers face another potentially dry summer, they need to be on the watch for anthrax.
While fairly uncommon, anthrax is a soil-borne disease that can quickly kill cattle, bison, sheep, goats and horses. Animals tend to graze closer to the soil during drier years, which places them at greater risks of contracting the disease.
“At this point, it’s something to keep in mind and be aware of, especially if you’re in an area where there has been a history of anthrax,” said Reynold Bergen, the science director with the Beef Cattle Research Council.
As well, flooding in southern Alberta earlier this spring could put producers there at greater risk if such areas have had a history of the disease, he added.
“The time to be most worried is when there has been a big flood because of the soil erosion, and the bacteria is exposed to the air and forms spores. Those spores are really resistant to tough conditions and they can live in the soil indefinitely.”
About 20 to 25 anthrax outbreaks have occurred in Canada since 1967, according to the BCRC. Cases have been reported in the Rural Municipality of Armstrong in Manitoba and the RMs of Fillmore, Garden River, Wellington, Hazel Dell and North Battleford in Saskatchewan.
It’s also been found in the Fort Vermilion area in Alberta, as well as in bison herds in Wood Buffalo National Park.
The biggest outbreak was in 2006 in both Manitoba and Saskatchewan, which killed more than 800 animals on 150 premises.
The disease usually shows up in July through to mid-September.
Bergen recommended producers speak with their veterinarians to determine if they should get their animals vaccinated. Doses cost $2 each and booster shots two to three weeks after the initial dose are recommended in heavily contaminated areas. Vaccination will protect animals within seven to 10 days.
If there is a suspicious death, producers are advised to call a vet because a prompt diagnosis will help prevent the spread of the disease.
Alberta Agriculture advises that farmers don’t open carcasses for assessment or for submitting tissues for sampling. They also shouldn’t move dead animals or call for dead stock pickup.
They should wear gloves and protective clothing when handling the carcass and take a blood sample as soon as possible from the tail vein of the freshest carcass. If a sample isn’t possible, producers should swab any excreted blood.
All carcasses suspected of anthrax should be covered and secured. Any surviving animals should be monitored for illness. Hands, arms, clothing and gloves should be washed and any disposables should be burned.
Producers should incinerate carcasses because it will destroy anthrax spores. Burying is an option but the spores may live on for decades and possibly resurface. Carcasses shouldn’t be buried in areas known for flooding.
Using antibiotics to prevent anthrax in exposed animals can be effective, according to Alberta Agriculture, though animals shouldn’t be treated with antibiotics if they were vaccinated two weeks previously. As well, antibiotics shouldn’t be used if animals are to be vaccinated within two weeks.
In rare cases, the disease can affect humans if it comes into contact with a skin abrasion or cut. Symptoms appear seven days after exposure, and include a red itchy bump that turns into a painless ulcer. A black spot appears in the centre within two days.
People with such symptoms should contact a doctor immediately. If untreated, there’s a 20 percent chance of death, though death is extremely rare if treated with antibiotics. The disease can’t spread from person to person.