There are many reasons for sudden liver failure in dogs, such as:

1. Drug poisoning: Dogs taking certain drugs for a long time, or accidentally ingesting human drugs, chemicals, etc., may cause liver failure. damaged, leading to liver failure.

2. Food poisoning: Dogs eat spoiled or toxic food, such as chocolate, grapes, onions, etc. The toxins in these foods may directly damage the liver and cause liver failure.

3. Viral infection: such as hepatitis virus, canine distemper virus, etc. These viruses will attack the dog's liver and cause it to suffer. damage and ultimately lead to liver failure.

4. Congenital causes: Some dogs are born with poor liver function or abnormal liver development, which may increase their risk of liver failure.