How long does cat stay in your blood and can it be picked up if you go for a blood test?

Cat allergens, such as proteins found in their saliva, skin, and urine, do not stay in your blood for a specific duration like a virus or bacteria. Instead, they can trigger allergic reactions if you're sensitive to them, but they are not typically detectable in a blood test. Blood tests for cat Allergies usually measure the immune response, specifically IgE antibodies, rather than the allergens themselves. If you're allergic, these antibodies may persist even after exposure has ended.