It was formerly referred to as feline urological syndrome or fus.
Crystals in cat urine images.
Struvite crystals are microscopic crystals that are found in the urine of some cats.
Urinary crystals are microscopic structures that can be found in the urine of many animals including cats.
Struvite specifically is a material that is composed of magnesium ammonium and phosphate.
The crystals themselves can be perfectly normal but become problematic when they combine to form grit or stones of varying shapes and sizes.
Male cats are far more likely to form urine crystals than females but that doesn t mean females can t be affected.
Crystalluria is a medical condition where crystals are expelled into the urine.
In some urine samples they do not have irregular protrusions but have smooth borders and can resemble calcium carbonate although these do not occur in the urine from dogs and cats.
These crystals can be observed under low magnification particularly when seen in large number however low numbers may only be seen at higher magnification.
Flutd includes crystal formation in the bladder which might obstruct the cat s urethra.
Many believe that this is due to cats eating commercial foods that acidify the urine.
If the crystals form in to stones diets are not effective at dissolving them and they require more drastic intervention.