There are many symptoms of feline panleukopenia which may range from mild to severe ones. It is not necessary that signs of this infection are always typical. The initial symptoms of feline panleukopenia include conditions like high fever, lethargy, depression, vomiting and dehydration. The duration of this infection may either be short or explosive.

Some of the serious and advance cases of infection may also lead to death. After the initial elevation of body temperature, the sickness may be present for about three to four days. During this time fever will fluctuate several times and will then fall to subnormal levels just before the death. The symptoms of feline panleukopenia in the later stages include anemia, diarrhea, dehydration and persistent vomiting. The signs of this infection are very prevalent and can be diagnosed easily by veterinarian. The virus of feline panleukopenia attacks the lining of the gastrointestinal tract which leads to internal ulceration and total sloughing of the intestinal epithelium.

The white blood cell also decreases during this infection and moreover it also causes the decrease in the platelet counts and hematocrit on a complete blood count.  Other symptoms of feline panleukopenia may also include abdominal pain, hunched over postural appearance, appearance of third eyelid, disinterest in food and water, loss of skin elasticity and self biting in the tail.