A woman Kim Richards calls her "second mother" will sue Kim for the dog bites she suffered from Kim's pit bull. The gruesome pics of the injuries make it clear ... she'll be gunning for lots of money.

Kay Rozario says she was in Kim's bedroom in March when she reached over the bed and Kingsley attacked her, biting through her hand all the way to the bone. The dog also went for her face but she blocked it with her arm, which was also injured.

Rozario tells TMZ ... Kim's first reaction was, "Please don't tell anyone. I'll lose my show."

Paramedics came and wanted to call animal control, but Rozario talked them out of it and said Kim would handle it.

Rozario tells us Kim has refused to pay any of her medical bills. So she'll file a lawsuit next week.

As we reported, the dog has attacked 4 people.