In either animals or humans, urine exits the body in acid form with a pH around 5 and or 6. Before leaving the body the urine is sterile, and has no damaging bacteria, pathogens, and or microorganisms. However, this is not the case if the animal has a bladder infection or urinary infection.
In mammals uric acid is the number one ingredient in the urine. Urochrome, (a yellow pigment) and cholesterol (also known as lipids), and urea are other main ingredients found in urine. The specific ingredients in urine including dog urine, will actually vary, and is dependent on diet and health, along with other factors. When urine is leaving the body it begins a process of significant changes. It picks up bacteria from the urethra and also from the skin. It also comes in contact with other microorganisms from sources such as carpeting and other surfaces.
These bacteria can now flourish. The warm acidic conditions of the urine are ideal for the bacteria to grow. The uric acid is broken down and becomes ammonia and CO2. This ammonia is extremely alkaline, with a pH of 11+. Strong, concentrated alkaline can damage dyes and cause color loss. What you think is a urine stain can actually be color loss. This color loss cannot be restored by simply cleaning.
Alkaline salt crystals are created as the acid in the urine reacts with the ammonia. These highly hygroscopic salts, as they’re termed, pull moisture from the air and remain slightly damp. When damp they stay active chemically. And this is the case in virtually every climate except extremely dry climates. As long the salts stay active, they will produce ammonia gas. When completely dry the ammonia gases stop but if moistened again such as during cleaning, they begin producing the ammonia gases again.
Ammonia gas is one of the parts of urines distinctive odor, which helps to locate and identify urine. Off-gassing from bacteria is another one of urines distinctive odors. The off gassing from the bacteria occurs while it is growing.
Urine is a complex composition. Many chemicals form as urine is being decomposed by the bacteria. This presents a challenging and sometimes difficult situation. In time, many of the complex organic compounds become part of the carpet or other fiber. Even when the bacteria have been killed, ammonia and these other chemicals produce strong odors. This is why something much stronger than a simple sanitizing cleaner is needed to neutralize the odor from dog urine!