Chronic kidney disease (CKD) is very common in older cats and it is known that high phosphate levels are associated with quicker disease progression. Phosphate is an important mineral in the body and is stored and used in every cell. Control of total body phosphate levels involves the co-ordination of a number of hormones and phosphate transporters found in the gut and the kidney. These two organs are key for total body phosphate control. Too much phosphate can result in kidney damage, which in turn leads to further increase in phosphate levels. Some cats handle excess dietary phosphate well and continue to regulate phosphate even when their kidneys start to fail, but others do not and their lifespan is shortened. This study’s aim is to use new genome sequencing technologies to identify genetic variants in phosphate transporters and other genes, which may be responsible for cats with early CKD developing high phosphate levels. Variant identification will lead to future studies exploring methods of preventing phosphate overload for cats with CKD while improving their quality of life and survival time.