if you want to know dog breed you just need to take dogs blood sample and you can just test it through DNA Testing Kit. 
Few days back i was thinking to buy a dog's DNA kit, as i was searching, i got some important details on http://www.pomskies.com/best-dog-dna-test-kit-reviews/. There are various options available to buy, which are Wisdom Panel, Mars Veterinary, Wisdom Panel Mixed Breed, Embark Dog & Canine Breed Identification Test kit to know which type of exact breed it is.