In some cats, the excessive breakdown of red blood cells leads to elevated levels of hemoglobin in the blood. Hemoglobin is then broken down into bilirubin, which causes a yellow pigment to appear in the skin, gums, and eyes. This condition is known as jaundice.In some cats, the excessive breakdown of red blood cells leads to elevated levels of hemoglobin in the blood. Hemoglobin is then broken down into bilirubin, which causes a yellow pigment to appear in the skin, gums, and eyes. This condition is known as jaundice.