According to wikipedia, Purina split up, so now the chicken food part is owned by Land O Lakes and the pet food part is owned by Nestle.
https://en.wikipedia.org/wiki/Ralston_Purina
Selected quotes from the wikipedia article:
Ralston Purina (originally Ralston-Purina) traces its roots to 1894
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In 1986, Ralston Purina sold Purina Mills, its US animal feed business, to British Petroleum. Purina Mills is now owned by Land O'Lakes.
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Ralston Purina became the subject of an acquisition bid by Swiss-based Nestlé, whose Friskies brand was the other leading US brand of pet food. Nestlé S.A. and Ralston Purina announced in January 2001 a definitive merger agreement.