What substances from pets cause allergic symptoms?
Animals produce various substances that can cause an allergic reaction. The main culprits are proteins in the urine, saliva, or dander (dead skin flakes). In cats, for example, the main substances that cause problems are proteins found in cat saliva which often mixes with house dust. In rodents such as mice, rats or guinea pigs, it appears that urine contains the substance that most commonly causes allergy.
