something i found about the possible causes of smelly urines-
A number of factors can influence the smell of urine. Consuming less water than required can negatively affect the smell in urine. Formation of kidney stones is also linked to change in urine odor. Dehydration- Insufficient fluid intake decreases volume of urine and makes it highly concentrated. When intake of water is less, there is a drastic change in the color and smell of urine. Concentrated urine has a strong smell similar to ammonia. A strong ammonia smell from the urine is an indication that the person is not drinking sufficient water.
Beverages like coffee that are popular all over the world can also change the smell of urine from nearly odorless to foul-smelling. However, one or two medium cups of coffee won't change urine odor. Those who have the habit of consuming 5-6 cups of coffee are the ones who complain about smelly urine. Many have reported urine odor similar to coffee after drinking coffee. Basically, coffee has diuretic properties, which means it stimulates fluid loss by increasing the urinary rate. This excess urine production often leads to dehydration, giving a strong smelly odor to urine.
Medications- Weird or unusual urine odor has also been linked to certain medications. Antibiotics used for treating bacterial infections are known to influence urine odor. So, those put on antibiotics such as amoxicillin or ciprofloxacin even for a short while are unlikely to pee odorless urine. Most patients taking antibiotics complain about drastic sudden change in urine odor which is strong and some refer it as yeasty smell. In general, whichever may be the class of antibiotic, change in urine odor is likely to occur.
Liver Problems- To be precise, urine giving out a bad smell can be a sign of liver failure, which means the liver is unable to carry out its functions efficiently. For instance, foul-smelling darkened urine could mean that the person is affected with hepatic (liver disease). It is observed that a yellowish-green colored pigment (bilirubin) is processed by the liver and only a miniscule amount of bilirubin combines with urine. However, if the liver is not working correctly, too much bilirubin escapes into the urine, giving it a distinct dark amber color. Apart from change in urine color, the odor during urination is horribly smelly.
Phenylketonuria is an inborn metabolic disorder in which the body loses its capability to breakdown an amino acid (protein) referred as phenylalanine. With the metabolism of phenylalanine taking a backseat, its concentration in the blood and urine increases. In such circumstances, the urine is said to be emitting a strong, foul, musty or mousy smell.
Other Causes-
Diabetes: Health problems too can lead to foul smell in urine. More specifically, people suffering from diabetes excrete urine that has an abnormal smell. This is because diabetics, as well all know, have high blood sugar levels. This excess sugar often gets passed down to the urine, giving it a characteristic sweet smell. Smelly urine is often regarded as a symptom of diabetes. People with untreated or mismanaged diabetes in which diet restrictions are not being followed, pee that smells excessively sweet.
Food: Including certain foodstuffs in the diet can also cause smelly urine. Although asparagus is rich in nutrients and a healthy choice, including this vegetable in the diet can result into foul-smelling urine. Asparagus passes in the urine through the kidneys, that gives a distinctive odor to the urine. Doctors often prescribe dietary vitamin supplements for various medical conditions. However, these medications can actually bring about a change in the urine odor.