Causes of cats vomiting black liquid:

1. Cats vomiting black viscous liquid may be caused by the cat eating sharp objects that scratch the esophagus, poisoning, or viral infection caused by disease.

2. Cats suffering from infectious peritonitis will vomit repeatedly, and the vomitus will also be black.

Solutions for cats vomiting black liquid:

1. If it is caused by food or poisoning, it is recommended to stop feeding and give the cat a small amount of water to drink to clean the stomach. Keep an eye on your cat's condition and seek medical advice if necessary.

2. If it is caused by infectious peritonitis, etc., the owner should use corresponding anti-inflammatory drugs for the cat and cooperate with the doctor for active treatment.