Stray Cat Colonies Lacking Health Surveillance and Management Pose Infection Pressure for Aelurostrongylus abstrusus on Sympatric Domestic and Wild Felids

The prevalence of respiratory nematodes in domestic animals has increased in Europe in recent decades. <i>Aelurostrongylus abstrusus</i> is the most common parasitic nematode of the respiratory tract in felids, and an increase in its prevalence has been suggested in different European countries including Spain, with values ranging from 0% to 30%. The Baermann technique was used to detect metastrongyloid larvae in 93 faecal samples from cats living in colonies (n = 29), cats living in shelters (n = 30), and owned cats (n = 34). Eleven cats (11.2%) were infected by <i>A. abstrusus</i>, the only species detected. The prevalence in colony cats (34.5%, 10/29) was significantly higher than the 3.3% (1/30) prevalence in shelter cats. Conversely, <i>A. abstrusus</i> was not found in any of the owned cats. The results can be representative of other areas in the Mediterranean basin, indicating the need to improve feline management and knowledge about the distribution and abundance of this parasite through geographically wider studies in Spain. This study emphasizes the importance of deworming domestic cats, especially those from street and rural environments or with outdoor lifestyles. The results also urge the need for population and health control of street cat colonies. Incorporating a deworming protocol in the current trapping-neutering-release campaigns for cat population control will be essential.