The equine roundworm, Parascaris, is the major pathogenic parasite of foals, but has also been suggested to be involved in mild equine asthma (EA) in young Standardbreds. We intend to develop a serodiagnostic test with a saliva based sampling method for detection of early Parascaris infection. Basing roundworm treatment on individual samples will result in a reduction of anthelmintic drug use and thereby less selection for resistant parasites. In addition, we aim to use the above methods to investigate if larval migration of Parascaris through the lungs is a contributing cause of reduced performance and EA. Mild equine asthma affects approximately 10% of young racehorses and contributes to major economic losses for horse owners. In summary, the goal with the easy to use saliva test for Parascaris infection is to optimise the timing for parasite treatment and also to correctly diagnose the cause of EA and thereby offer the proper treatment.