Ah, the classic David-and-Goliath situation. Generally, ideas are not protectable, so if you have a new idea for, let's say a sun block for dogs, you can't prevent someone else from developing a sun block for dogs. You could protect the sun block formula (through a patent or trade secret), or the branding identification with your particular line (through trademark or trade dress).

If you've taken the steps to properly protect your intellectual property, you might be a more attractive target for acquisition (instead of outright theft). Consult with an intellectual property attorney to develop a plan of action (and a budget) for protecting your product.