My dog is constipated and ate Ex-Lax. Will it help or hurt him?

Ex-lax contains sennosides which cause water to stay in the intestinal tract which can help with constipation. They can cause diarrhea if too many are ingested, and sometimes abdominal cramping and discomfort as well. I agree that the amount of cocoa present is probably negligible, and I would guess that only 4 laxatives are unlikely to have much of an effect although it could take several hours for diarrhea to appear. I am a little concerned about the cause of Hercules' constipation however - it is rare for dogs to become constipated unless they have an underlying problem like kidney disease, high calcium levels, or bones or a foreign object causing a blockage in the colon. If the constipation continues or if you notice significant diarrhea you should see a vet.