American Scientist

What causes allergies to cats?

Eight different cat allergens are currently recognized by the World Health Organization. They're designated as Fel d 1–8. Of these, Fel d 1 is the primary cat allergen.

This protein is found in over 99 percent of U.S. homes. Its biological function is unknown.

Inhalation of Fel d 1 causes an immune response in people who are allergic. As a defense mechanism, the body produces antibodies. These antibodies trigger the release of histamine from mast cells. Histamine causes the symptoms of allergies.

Why do cats go crazy for catnip?

The compound that causes catnip's effect on cats is nepetalactone. It binds to protein receptors in the cat's nasal passages. This triggers responses in the cat's brain that make the cat exhibit behavior similar to that triggered by cat pheromones, including rolling, rubbing, and salivating. The effects last for around 10 minutes before wearing off.

Why does cat urine smell so bad?

Fresh cat urine doesn't have a strong odor. However, over time, it develops a strong smell. Felinine, an amino acid in cat urine, gets broken down by enzymes into 3-methyl-3-sulfanylbutan-1-ol (MMB). This, along with the ammonia produced by the breakdown, gives cat urine its pungent smell.

Cat ketone (4-methyl-4sulfanylpentan-2-one) is another key cat urine odorant. It also occurs naturally in Sauvignon grapes, and is a key contributor to the odor of black currants.

Cat litter absorbs urine and odors. In cases where cats urinate elsewhere in your house, enzymatic cleaners should be used. These break down odorous compounds.

© Andy Brunning/Compound Interest 2020 - www.compoundchem.com | Twitter: @compoundchem | This graphic is shared under a CC BY-NC-ND 4.0 license.