Sorry, forgot to post the recall link:
http://www.fda.gov/Safety/Recalls/ucm299606.htm
What brand of dog food are you feeding them? There has been a recent recall of Diamond foods. "Diamond Pet Foods temporarily suspended delivery on April 8, of all products made at its Gaston, S.C., plant." I have been reading on another forum about pets who have been getting very ill and some even dying that have been on this brand of food.
Also, "Cocoa mulch can be harmful to dogs and other pets. This mulch is made from cocoa bean hulls, and dogs may eat it because they're attracted to the smell of cocoa.
Cocoa mulch contains theobromine, a caffeine-like chemical dogs have trouble digesting. Dogs that eat significant amounts of the mulch could have upset stomachs or begin trembling. The chemical could also cause a dog's heart rate to accelerate ("tachycardia"). Some manufacturers include warnings on their cocoa mulch packages to alert pet owners that the product is potentially harmful to dogs."
http://www.ehow.com/list_7533705_mulch-dangers.html
Please contact your vet if they are still having problems.
Sending positive thoughts for your pets' health and safety.
What kind of mulch did they put down in your landscaping beds?
Ghilly