Feline infectious peritonitis (FIP) is a devastating disease of cats that, up until recently, has been uniformly fatal. FIP occurs when the very common but non-harmful feline coronavirus mutates to a form that can spread throughout a cat’s body and cause severe disease. A significant challenge to diagnosing FIP is that nearly all cats have the non-harmful version of feline coronavirus, so invasive and costly testing, including biopsies of organs, are sometimes needed to reach a diagnosis. Research into less invasive diagnostic tests has led to diagnostic tests that look for the genetic code of the FIP version of the virus in fluids and tissues from sick cats. Veterinarians heavily rely upon these tests, along with clinical signs, to support a diagnosis of FIP. A downside to the currently available tests is that they require specialized laboratories, resulting in several day turnaround time for results. With new antiviral drugs becoming available that appear to cure FIP, there is an urgent need to develop rapid diagnostic tests that can aid in an early diagnosis of FIP so therapy can be instituted in a timely fashion. Here we propose developing a diagnostic test that utilizes new technology, CRISPR, to recognize the genetic code of the virus that causes FIP. This test requires minimal laboratory equipment and expertise once developed, and the results are reported on a simple dipstick test that shows a color change line when the genetic code is detected.