Why Does Cat Urine Smell Like Ammonia?

The main component of cat urine, which gives it its pungent smell, is ammonia. Cats have a high protein diet, and during protein metabolism, their liver converts nitrogen to waste products like urea. When urea combines with bacteria found in cat urine, the chemical reaction breaks down urea molecules releasing ammonia gas — hence that familiar, unmistakable pungent, acrid stench in your home whenever the litter box isn't frequently scooped or the litter needs changing.

Other contributing factors that exacerbate the odour are:

pH levels in their urine. The urine of carnivores — cats, dogs, foxes and raccoons have acidic urine — between a pH level of 6.0 and 6.5 — which causes urea to more easily decompose into odorous ammonia.

Bacterial Concentration In Cat Litter Boxes. Cat litter traps urine, creating a highly concentrated area of bacteria growth, increasing decomposition rates, making your litter box release even more unpleasant aromas over time.