Distribution of Eimeria oocysts in cattle and sheep–goat farms in the Province of Palermo in the context of climate change (2024–2025)

Introduction. Coccidiosis is a widespread enteric parasitic disease in domestic ruminants, caused by protozoa of the genus Eimeria, mainly affecting young animals and leading to diarrhea, growth retardation, and production losses. Transmission occurs through ingestion of oocysts shed in feces, which become infective after sporulation under favorable environmental conditions. Mild temperatures and high humidity, increasingly common in the context of Mediterranean climate change, can enhance the survival and spread of the parasite in livestock systems.

Methods. This study analyzed fecal samples from cattle and small ruminant farms in the Province of Palermo over the 2024–2025 period. A total of 5,902 samples were examined using coprological analysis to detect Eimeria oocysts. Specifically, 2,956 samples were analyzed in 2024 and 2,946 in 2025. Parasitological data were compared with local climatic parameters, including average monthly temperatures and precipitation, in order to assess possible correlations between environmental conditions and infection trends.

Results and conclusions. In 2024, 274 samples (9.3%) tested positive, with a peak observed in October. In 2025, 466 samples (15.8%) were positive, showing a significant increase, particularly during the autumn months from September to December. This rise appears to be associated with favorable climatic conditions, characterized by mild temperatures and increased humidity due to rainfall. These factors promote oocyst sporulation and survival, leading to greater environmental contamination. The findings highlight the importance of parasitological monitoring and the implementation of appropriate hygiene and management measures to limit the spread of coccidiosis. They also emphasize the need for targeted seasonal prevention strategies and improved environmental management, especially during high-risk periods linked to ongoing climate change, with benefits for animal health and the sustainability of livestock production systems.