The highly lethal feline infectious peritonitis (FIP) has remained a constant threat to cats - especially kittens - while vexing scientists who have spent three decades attempting to prevent, treat, or even diagnose the disease.

The inability to save cats infected with FIP has led to much heartache for their owners, who usually see their pets pass away within weeks of contracting the disease.

After years of frustration, Cornell University researchers have finally made a breakthrough discovery that could signal the beginning of the end for FIP.

Looking for telltale signs of mutation

According to a news release from the university, past research has not been able to tell the difference between the benign feline enteric coronavirus (FECV) and FIPV, which is a mutated version of FECV. The roadblock has left veterinarians with no way to test for FIP, and has prevented the development of any vaccines or treatments. 

Like other researchers tackling the mysterious disease, Gary Whittaker, virology professor at Cornell's College of Veterinary Medicine, took on the task of trying to definitively distinguish FECV from FIPV. His approach involved closely studying coronavirus particles, where he thought he might be able to find a distinct location where the mutation from FECV to FIPV occurred.

Whittaker's suspicions were confirmed when he found that the spikey proteins covering the coronavirus particles changed shape when they were cut by macrophage proteases that had been "hijacked" by FIPV. He observed distinct differences in the spike proteins and the genes that code them, which provided the highly sought-after way to distinguish between FECV and FIPV.

"Comparing viral genetics, our lab found exactly what changes when FECV mutates into FIPV," Whittaker said.

Whittaker was able to consistently locate this mutation across hundreds of feline coronavirus samples he had collected from pet owners, veterinarians, and Cornell's pathology vault, the school reported.

Whittaker said his group's research is a tremendous first step toward developing life-saving measures to prevent and treat the deadly disease in cats and other species.

"Using a unique interdisciplinary approach, we've found the first known molecular basis for FIP," said Whittaker. "This could have implications for similar coronaviruses, such as FIPV's deadly cousin in ferrets and another human-infecting cousin emerging in the Middle East. For now, it finally unlocks the door to developing the world's first effective diagnostics, preventions, and therapies for FIP in cats."