Geraniums are toxic to dogs, so if he just ate this, you can induce vomiting to help him get rid of it, by following these instructions: (feed a small meal or some soft bread first)
"Three percent hydrogen peroxide is quite effective in making dogs and cats vomit. You must be sure to use three percent peroxide and not hair coloring strength peroxide. Despite the label indicating that hydrogen peroxide is toxic, it is safe to give to dogs for this purpose. It is considered toxic since it induces vomiting and therefore does not stay in the body. The appropriate dose of hydrogen peroxide is one teaspoon per 10 pounds of body weight. If you have an oral syringe, one teaspoon equals 5 cc or 5 ml. Once given, walk your dog around or gently shake the stomach area to mix the peroxide with the stomach contents. Vomiting should occur within 15 to 20 minutes. If no vomiting occurs, you can safely repeat the three percent hydrogen peroxide once. If it is still not effective, your dog may need to be seen by a veterinarian for stronger vomiting medication.
Once the hydrogen peroxide is given, it is important to watch your pet so that he does not re-ingest the substance. If there is concern about toxicity, collect and take a sample of the vomitus to your veterinarian."
Just for your future reference, this is a list of the many plants toxic to dogs (although no list is totally inclusive):http://www.veterinarypartner.com/Content.plx?P=A&A=191
If your dog begins to exhibit any of the following symptoms: excessive salivation, nausea, vomiting (before you induce it), diarrhea, difficulty with coordination/stumbling, have him seen by an ER vet, immediately. Also, if you are unsuccessful with trying to get him to vomit, bring him to the nearest ER vet center for evaluation and treatment.
I hope all will be well with your furry boy.
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Edited by Cher on 4/15/2010 at 4:28 AM EST