Dr. Selmer: The most common side effects of Benadryl are lethargy, dry mouth and urine retention. Diarrhea, vomiting and decreased appetite are possible, but not common. There is no evidence that Benadryl will cause fear in dogs.
What to expect when you give your dog Benadryl?
Benadryl Side Effects in Dogs Common side effects of Benadryl include drowsiness, dry mouth, urinary retention, hypersalivation, increased heart rate, and loss of appetite for some dogs. The side effects of Benadryl for dogs are typically thought to be minor as the medication is widely recommended for dogs.
How long does it take for Benadryl to wear off in dogs?
It usually takes 24 hours for Benadryl to wear off and stop working. However, for dogs with liver or kidney disease, the effects can last longer. Always talk to your veterinarian before giving Benadryl, especially if your dog has chronic liver, kidney, or heart problems.
How do I know if my dog is having a reaction to Benadryl?
An allergy to diphenhydramine will have similar symptoms to other allergies, including: Red rashes on the skin. Swelling of the face and tongue. Diarrhea, vomiting, and upset stomach.
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