(source: American Veterinary Medical Association)

The first visible signs an owner might notice include generalized depression, loss of appetite, high fever, lethargy, vomiting, severe diarrhea, nasal discharge, and dehydration. Sick cats may sit for long periods of time in front of their water bowls but not drink much water. In some cats, the fever will come and go during the illness and abruptly fall to lower-than-normal levels shortly before death. In young kittens, the virus can also damage the brain and the eyes.

If you notice any signs of illness in your pet, contact your veterinarian right away. Since there are no medications capable of killing the virus, intensive care and treatment are critical to support the cat’s health with medications and fluids until its own body and immune system can fight off the virus. Without such supportive care, up to 90% of cats with this disease may die.