Jaundice is a typical symptome at beginning. Vitamin B12 injection or Drops (Methylcobalamin). And liver support. A “Same” product : Zentonil or Denamarin. When he is very Bad, than Infusion by vet.
It’s typical for FIP and much more for wet FIP. Because the liver is often involved. Jaundice is the beginning of Organ failure. A sign that FIP is near to win the fight and a sign that death is near.
When FIP isn’t treated the organs begin to failure. The end is often a multiple organ failure. First liver, so cat get anemic and later bilurubin gets high.. And jaundice begins, after liver fail, the kidneys begin to fail, the cat is poisoning internally. It is most time a symple cause or symptom.
The FIP is like a war. Tries to kill all enemies , Not interested which way, the fastest is the best and it used all ways, Multiple and fast and bad.