What should i feed my 7 month old Maltese Terrier?

Coco (my puppy) has had dark sloppy poo's for just over a week now. The Vet said to give him metamucil with his food, but what sort of food,boiled chicken and rice, mince and pasta.??????

~Quality foods: Innova-meat and quality grains, California Natural-simple ingredient food for sensitivities, EVO-grain free, Karma-95% organic; all made by Natura- http://www.naturapet.com/Wellness-meat and quality grains with several formulas, Wellness Core-grain free; made by Old Mother Hubbard- http://www.wellnesspetfood.com/Orijen-all grain free with several formulas; made by Champion foods-http://www.orijen.ca/orijen/products/Canidae- are meat and grain- http://www.canidae.com/ Merrick-meat and grain, Merrick Before Grain-grain free- http://www.merrickpetcare.com/store/Artemis-meat and grain with a variety of formulas- http://www.artemiscompany.com/products.asp?cat=fresh_mixTaste of the Wild-grain free- http://www.tasteofthewildpetfood.com/products/Nature's Variety- Raw frozen diet- offering chicken, beef, lamb, venison, rabbit, and organic chicken, Instinct-grain free, Prairie-meat and quality grains- http://www.naturesvariety.com/Solid Gold-Barking at the Moon-grain free, several other formulas with meat and grains- http://www.solidgoldhealth.com/products/showcat.php?cat=0Now!-grain free, Go!-quality meat and grains and grain free formulas; all made by Petcurean- http://www.petcurean.com/index.phpEagle Pack Pack Holistic-meat and quality grains, Eagle Pack-meat and low quality grains including corn- http://www.eaglepack.com/Pages/EP_Products.htmlTimberwolf-grain free and meat and grain formulas- http://timberwolforganics.com/pet-foodsAvoDerm-meat and quality grains, Pinnacle Holistic-meat and quality grains, allergen free; all made by Breeders Choice- http://www.breeders-choice.com/dog_products/Formm-grain free formula- http://www.frommfamily.com/

soft dog food. any.