Clinical Presentation and Diagnosis of Anthrax in Iranian Goats

Background: Anthrax is considered one of the most important zoonotic diseases due to its widespread distribution, significant economic losses, and potential risks to public health. The manifestation of anthrax in goats is comparable to its presentation in other small ruminants. Objectives: To enhance understanding of the clinical signs and post-mortem findings of anthrax and improve its diagnosis in the goat population of Iran, this study examined the occurrence of anthrax in goats in some provinces of Iran between 2016 and 2021. Methods: Among a population of 3,465 goats, 50 cases of sudden death were documented. Samples were collected from recently deceased animals, including bone marrow and blood from ear veins. These samples were sent to the laboratory for direct examination, culture, and molecular assay (polymerase chain reaction [PCR]). Results: Out of the collected samples, 36 cases were attributed to anthrax. Among these deaths, 27 animals were found dead, while nine goats were slaughtered before succumbing. Bacillus anthracis was confirmed in all 36 suspicious samples using direct examination and PCR. Additionally, 11 samples (30%) were found to be culture-positive for anthrax. It is worth noting that classic signs of anthrax, such as unclotted blood oozing from natural orifices and the absence of rigor mortis, were not observed in 19 dead goats. Conclusion: This study reveals that there are instances of anthrax in goats where the typical clinical signs, such as blood oozing from natural body orifices, are absent. This finding should be considered during the differential diagnosis, especially when the classic signs are used as criteria.