Anthrax (Bacillus anthracis)

These information sheets are provided for your interest. They should not replace veterinary advice from your veterinary surgeon.

Whilst every effort is taken to ensure the accuracy and completeness of the information provided, your specific circumstances must be discussed before advice can be given.

Whenever we investigate a sudden death, we first rule out anthrax, as opening a carcase that has died as a result of anthrax would place all those around in danger of infection.

The test is done by taking a blood sample from a peripheral vein, making a smear on a clean glass slide and staining it using Polychrome Methylene Blue (MacFadean's). The stain would show Bacillus anthracis (anthrax) as rod-shaped bacteria in the blood, with the central core stained blue and the edges stained pink.

Bacillus anthracis stained with Polychrome Methylene BlueNot Bacillus anthracis stained with Polychrome Methylene Blue

 

The image on the left shows anthrax in a blood smear, stained with Polychrome Methylene Blue. Note the formation of chains, and the capsule which stains pink and which has broken up to some degree here. The image on the right shows a blood smear with similar blue staining rod-shaped bacteria. There is no pink staining capsule present here, and the bacteria mainly occur in singles, rather than chains.