possible side effects of benadryl in dogs

Question
What are the possible side effects of giving banadryl to dogs?

Answer
Side effects in people are: difficulty breathing; closing of throat; swelling of lips, tongue, or face; or hives. Other, less serious side effects may be more likely to occur: sleepiness, fatigue, or dizziness; headache; dry mouth; or difficulty urinating or an enlarged prostate. Symptoms of a Benadryl overdose include extreme sleepiness, confusion, weakness, ringing in the ears, blurred vision, large pupils, dry mouth, flushing, fever, shaking, insomnia, hallucinations, and possibly seizures.

I do not know if a dog would experience the same side effects as a person, but you should always consult your veterinarian before giving your dog any medication, particularly any that is intended for people.  http://www.drugs.com/benadryl.html