Regional distribution of feline lungworm Aelurostrongylus abstrusus in cats from Spain.

Aelurostrongylus abstrusus, a respiratory nematode affecting worldwide cats, has different prevalence across Europe. This study aims to evaluate the rates of positivity of this parasite in the different regions of Spain, analyzing fecal samples sent to a reference laboratory for the Baermann-Wetzel technique, between 2017 and 2023. The estimated overall infection rate in Spain was 9.4 %, being the positive cases distributed throughout all climatic regions of the country, highlighting the wide distribution of this parasite. The northwestern region had the highest infection rate (19.5 %) and the central region the lowest (5 %). Winter was the season with the highest detection rate (11.6 %) and young cats (<1 year old) were 5.29 times more likely to be positive than older cats (p < 0.05). These findings highlight the wide distribution of A. abstrusus throughout the different climatic regions of Spain, being important to include it as a differential diagnosis in the investigation of respiratory processes in cats.