my dog has food intolerance to certain foods i beleive its fish but not certain she scratches, bites her feet ,and get an upset tummy from it allDo you mean to check for allergies?
If yes, your vet should be able to pull the blood and send the sample to the lab themselves. Heska is one of the labs that some vets use. link to the site http://heska.com/ if you mean a intradermal skin testing this is usually done by a specialist.
here is another link http://www.peteducation.com/article.cfm?c=2+1587&aid=504
why do you ask?