How much Benadryl is toxic to a dog? A Complete Guide

Symptoms of Benadryl Poisoning in Dogs

Although Benadryl is generally safe for dogs, some side effects can occur. Side effects usually occur within an hour of administration. They are typically mild and can include:

  • Depression
  • Drooling
  • Excitability
  • Lack of appetite
  • Rapid breathing
  • Rapid heart rate
  • Sedation
  • Overdoses of Benadryl are more often caused by your animal getting a box of the medication from the garbage or medicine cabinet than by being given too much. If you see these signs of an overdose, contact your veterinarian immediately.

  • Abnormal heart rate
  • Aggression
  • Agitation
  • Difficulty breathing
  • Erratic or aggressive behavior
  • Extreme drowsiness
  • Fever
  • Increased blood pressure
  • Muscle tremors
  • Red eyes
  • Types

    Along with a version of diphenhydramine by the name of Vetadryl developed specifically for cats and dogs, there are a few other first generation antihistamines that can be used for dogs. These can include:

    Chlorpheniramine – This antihistamine is frequently used in small animal veterinary practice and is less likely to cause drowsiness than some of the others

    Clemastine – Clemastine is classified as an antipruritic (anti-itch), as well as a sedating antihistamine, and is tends to exhibit fewer side effects

    Hydroxyzine – This drug is a more aggressive antihistamine, but also has more potent side effects

    Meclizine – Commonly used to reduce nausea, particularly nausea caused by motion sickness

    What to Do If Your Dog Overdoses on Benadryl

    If you suspect that your dog may have eaten any Benadryl, or if you think you may have accidentally given too much, contact your veterinarian or an emergency veterinary clinic immediately. You could also consider calling Pet Poison Helpline at 855-764-7661 or ASPCA Animal Poison Control at (888) 426-4435. They can help you determine whether your dog may have consumed a dangerous amount, and what to do next, for a reasonable fee.

    Diagnosis of Benadryl Poisoning in Dogs

    Unless the consumption of the medication was witnessed, the diagnosis of allergic reaction or poisoning is likely to be driven by the signs, and supportive treatments will be started as soon as possible. If you see your dog ingest a large amount of Benadryl, or he seems to be having a reaction to prescribed Benadryl, gather as much information about the incident as possible and provide the details to the veterinary team upon arrival at the clinic. The age and weight of your dog will be measured, and a urinalysis, complete blood count, and biochemistry profile will also likely be recommended at the veterinarians office at this time as well.

    Currently, there are no reliable tests that can detect the substance in the blood or urine, so the diagnosis is based on clinical signs and timing. It is helpful to have the packaging on hand. The packaging can help determine the strength of the particular type of Benadryl that your pet consumed, as well as ensuring that toxicity from any additional ingredients is addressed before it becomes a problem.

    Benadryl For Dogs? Dr. Dan Explains

    Benadryl dosage for dogs – Ive heard that you can give benadryl to a dog, so how much should I give to my dog with allergies – weighs around 25 lbs.

    Benadryl is an antihistamine. Its active ingredient is diphenhydramine. Diphenhydramine can be given to dogs for a variety of reasons. It can be used for allergic respiratory disease, cough, pruritis (itchy skin) due to allergy, motion sickness, and mild sedation. It should not be used if your dog has urinary retention, glaucoma or hypertyroidism. Side effects include drowsiness and CNS depression (Impaired thinking and perception, decreased heart rate, slow breathing)

    The general dose of Benadryl (diphenhydramine) is 2 to 4 mg/kg up to three times day. If your dog weighs 25 lbs (11.3 kg) the dose of Benadryl would be 22.6mg to 45.2mg up to three times a day.

    Benadryl tablets are available in 25mg and 50mg strength. If you were using the Benadryl 25mg tablet you could give 1 to 2 tablets up to three times day.

    It is worth noting a vet should be consulted to reassure you that your dogs symptoms are not indicative of something more serious.