Pica

• from The Holistic Dog Book: Canine Care for the 21st Century by Denise Flaim
  

  Crab Apple.  Animals with poor hygiene can benefit from this essence, which has a cleansing effect. It is also useful in helping stop obsessive grooming behaviors, or unwise dietary habits such as coprophagy (stool eating) and soil or rock eating.
  
  

Gulpers

After discussing with your vet, here are some things to consider

Where do we go from here? - Multi Dog Household

So you've taught some basics like sit, stay, come, leave it, etc..
What's next?