August 2008
What causes anthrax?
Anthrax is caused by bacteria known as Bacillus anthracis. When an animal infected with the disease dies, the bacteria leave the animal and turns into spores which live in the soil. These spores are extremely resistant and can survive in the soil through extremes in temperature and moisture. Also to be noted is that anthrax is a zoonotic disease, which means it can be transferred to other animal species and humans. However, human infections are extremely rare and can easily be prevented. They can also be treated with a variety of antibiotics.
Where does anthrax come from?
The spores survive in the soil for a long time. They prefer neutral or alkaline, calcareous soils. The spores may be brought to the surface of the soil and cattle may be exposed to them when environmental conditions favor exposure of buried spores. Periods of flooding can move spores up to the soil surface, and drying of wet areas will expose spores to grazing livestock. Disruption of the soil by excavation can also bring spores to the surface. When animals graze on soil where spores are present, they ingest the bacteria on plants or from the soil. Cases of naturally-occurring anthrax are reported every year in Canada, particularly in locations where these climatic conditions are present.
When should I call a veterinarian?
Symptoms vary and in most cases, animals are found dead. Symptoms, when seen, include staggering, shortness of breath, trembling, collapse, a short period of convulsions and death. These symptoms are usually quite rapid. Also common are bloody discharges from body openings (i.e. the nose). Dead animals should not be moved or opened, as this will allow the bacteria to form spores that can be spread to previously unaffected areas. Anthrax is a reportable disease. Contact your local veterinarian immediately if anthrax is suspected. They will contact the Canadian Food Inspection Agency if required.
How do you treat anthrax ? Can it be prevented?
Follow the advice of your veterinarian, as every situation is different. Early diagnosis and treatment is important because of the rapid action of the disease. If you suspect anthrax, call your veterinarian immediately.
Anthrax can be treated with antibiotics or vaccination. Your local veterinarian and Canadian Food Inspection Agency will advise the owner about which to use. Antibiotics will kill the bacteria and may be effective to treat animals that are already infected but don't offer long-term protection against infection. The vaccine will produce immunity but requires seven - ten days for immunity to develop.
Antibiotics and vaccine cannot be used at the same time. Antibiotics will prevent the vaccine from working. If antibiotics are used, the vaccination must be postponed until the effect of the antibiotic has worn off.
Is there any need to restrict public access to my property to stop the spread of the disease?
Many thousands of anthrax spores are required to cause an infection. The negligible amount that could be introduced to your property by a casual visitor or a vehicle poses virtually no risk. If you find a dead animal on your property that shows signs of an anthrax infection (as described elsewhere in this document), please contact your local veterinarian. Do not disturb or open the carcass until an assessment is made.
Can animals other than cattle get the disease?
Although all mammals are susceptible to anthrax, it is primarily a disease of herbivores. Cattle, sheep, goats and horses are highly susceptible. Laboratory animals such as guinea pigs, rabbits and mice readily contract the disease. Omnivores, like pigs, and carnivores, such as dogs and cats, are less susceptible and can sometimes be exposed to the bacterium repeatedly before becoming infected. Birds and wildlife also appear to be at a lower risk for anthrax.
References:
Producers looking for more information on anthrax should contact their local veterinarian.
News Release
May 3, 2007 - Agriculture Knowledge Centre Bulletin: Anthrax Remains A Threat In 2007
July 6, 2006 - Agriculture Knowledge Centre Bulletin: Wet Conditions Increase Anthrax Risk
