Transboundary Emerging and Exotic Animal Disease/ Exotic Animal Disease Practice Exam

Which method is suitable for detecting anthrax without opening the carcass?

1. Check a stained blood smear for characteristic organisms

2. Check a heart blood sample using ELISA

3. Check a fecal sample for the characteristic organisms

4. Check a skin scraping for antigens

The correct answer is: Check a stained blood smear for characteristic organisms

Detecting anthrax without opening the carcass can be effectively done by checking a stained blood smear for characteristic organisms. This method works because anthrax, caused by the bacterium Bacillus anthracis, leads to the presence of the organism in the blood of infected animals. By preparing a blood smear from the heart or another blood source of the carcass, one can identify the characteristic large, Gram-positive bacilli and their unique morphology under a microscope after staining. This approach is non-invasive, allowing for the collection of samples that do not require the carcass to be opened. In contrast, other methods listed may not be as suitable for detection in this context. The ELISA method is more commonly used for antigen detection in various tissues or fluids but would typically require access to specific blood samples rather than examining the heart blood directly without prior intervention. Fecal samples are not ideal for detecting anthrax, as the organism is not consistently shed in feces, especially in acute cases. Similarly, skin scrapings are not reliable for detecting anthrax since the disease does not primarily manifest in the skin tissues or lead to significant antigen presence there, especially without visible lesions indicative of cutaneous anthrax. Thus, analyzing a stained blood smear is the most appropriate