** Shares of pet pharmacy firm PetMed Express PETS.O rise 30% to $3.73
** Cardone Ventures, backed by billionaire investor Grant Cardone, has offered to buy PetMed Express for $4.25/share in cash, valuing the company at about $89 mln
** The proposal, which is unsolicited and non-binding, was sent to PetMed's board and does not include any financing conditions, Cardone said
** There is no certainty that the offer will lead to a deal - Cardone
** Stock down 25% YTD
(Reporting by Kamal Choudhury in Bengaluru)
((Kamal.Choudhury@thomsonreuters.com;))