"I feel incredibly sad and wish I could offer more than condolences," Ronson wrote on her Twitter page. "Unfortunately there are no words to describe how sorry I am. There is absolutely nothing I can say that will alter one minute of today, nothing."
The case is under investigation by the Los Angeles County Department of Animal Care & Control. "The incident is still an allegation until such a time that a witness provides evidence to support the allegation," Michelle Roache, a spokesperson for the department, tells PEOPLE.