Veterinarija ir Zootechnika

Background and Aim: Lice are among the most common ectoparasites in goats. They cause health problems: weight loss, hypoproteinemia, nutritional deficiencies, reduced vitality and anemia. The present study aims to investigate the seasonal dynamics of the most common species of lice in naturally infested goats and the influence of temperature and precipitation levels on it. Materials and Methods: The seasonal dynamics were monitored by examining twenty goats, ten from each of two different small herds in the Stara Zagora region. At the beginning of each month, over a period of two years (from January 2018 to December 2019), the individual and average intensity of infestation were determined dynamically. Results: Our findings reveal that parasitosis caused by Bovicola caprae and Linognathus stenopsis persists throughout the year, with clear seasonal patterns. Infestation intensity peaks in March, following the coldest months (December–February) when average temperatures are around 2–3°C. During the warmer months (June–August), when temperatures rise to 21–25°C, infestation intensity significantly declines. Statistical analysis confirmed a moderate negative correlation between infestation intensity and ambient temperature (r = -0.411, p < 0.0001), while no significant correlation was found with precipitation (r = 0.023, p = 0.7184) Conclusion: The observed seasonal dynamics of both lice species on goats clearly demonstrate that winter provides optimal conditions for the development of their populations, confirming that phthirapterosis in goats in our region has a pronounced winter seasonality.