Signs of Benadryl Overdose In Dogs & What to Do
Benadryl, known by its generic name diphenhydramine, is a popular over-the-counter antihistamine that many pet owners consider for their dogs. It’s often used to help with allergies, motion sickness, and even anxiety. While it can be effective, it can have serious consequences if not used correctly. Originally designed for humans, Benadryl has made its way into veterinary use because of its versatility and generally mild side effects when given correctly.
However, the difference between safe use and potential harm can be small, so it’s essential to understand how to give your dog Benadryl. Dosages will likely differ from human to dogs due to differences in metabolism and physiology. This guide will walk you through important facts about giving Benadryl to your furry friend, including dosage recommendations, signs of overdose, and how to keep your pup safe.
Check with Your Vet Before Giving Benadryl
Before giving your dog Benadryl, always check with your veterinarian. They’ll be able to provide personalized advice based on your dog’s size, health conditions, and any other factors that could affect how the medication works. This step is crucial to avoid any unwanted side effects or complications. By understanding the potential risks and proper usage, pet owners can make informed decisions about their dog’s health and prevent accidental overdoses.
What is the Correct Dosage for Your Dog?
Giving the correct dose of Benadryl is key to keeping your dog safe. Jennifer Coates, DVM wrote: “According to the Merck Veterinary Manual, the standard dose for Benadryl® is 2–4 milligrams per kilogram of body weight, or 0.9–1.8 milligrams (mg) of Benadryl® per pound.
Therefore, a simple and practical dose is 1 mg of Benadryl® per pound of your dog’s weight, given two to three times a day. For example, a 10-pound dog might receive a 10 mg dose in the morning, afternoon, and evening.” However, this can vary depending on your vet’s advice and your dog’s specific needs.
Here’s a general dosage guide, though it’s always best to consult with your vet prior to giving Benadryl or any medicine to your dog
| Dog’s Weight | Recommended Dosage |
| 10 lbs | 10 mg |
| 20 lbs | 20 mg |
| 30 lbs | 30 mg |
| 40 lbs | 40 mg |
| 50 lbs | 50 mg |
Some dogs may need lower or higher doses depending on their health. Also, be sure to check the label on your Benadryl product—some formulations contain extra ingredients that can be harmful to dogs. To be safe, stick with vet-approved versions of human Benadryl that contain only diphenhydramine.
Recognizing Signs of a Benadryl Overdose
Although Benadryl is generally safe when given correctly, too much can lead to serious health problems. If your dog accidentally gets an overdose, it’s important to act quickly. Here are some signs to watch for:
Neurological Symptoms:
- Extreme drowsiness or sedation
- Agitation or hyperactivity
- Confusion or disorientation
- Seizures or tremors
Heart and Circulation Issues:
- Rapid heartbeat
- Abnormal heart rhythms
- High blood pressure
Digestive Problems:
- Vomiting
- Loss of appetite
- Constipation or difficulty urinating
Breathing Issues:
- Rapid breathing
- Difficulty breathing
Other Warning Signs:
- Dilated pupils
- Fever
- Weakness or trouble walking
Potential Side Effects of Benadryl in Dogs
Even when given at safe doses, Benadryl can still cause mild side effects. Here’s what to look out for:
- Drowsiness – Most dogs get sleepy, which is often the desired effect.
- Dry Mouth – Increased thirst or difficulty swallowing can occur.
- Urinary Retention – Some dogs may urinate less frequently.
- Gastrointestinal Upset – Vomiting, diarrhea, or loss of appetite are possible.
- Increased Heart Rate – Less common, but can be risky for dogs with heart problems.
- Blood Pressure Changes – Benadryl can cause fluctuations in blood pressure.
- Behavioral Changes – Some dogs may become hyper instead of sedated.
- Allergic Reactions – Though rare, some dogs may have an allergic response to Benadryl itself.
It’s important to be aware that Benadryl can cause diarrhea in some dogs. While usually mild and temporary, persistent or severe diarrhea should be reported to your vet. Also, dogs with glaucoma, high blood pressure, or thyroid problems may be more at risk of complications.
What to Do If Your Dog Overdoses on Benadryl
Ellen Malmanger, DVM, wrote in the PetMD article: “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.”
How Much Benadryl Is Too Much?
Knowing the lethal dose of Benadryl can help prevent tragic accidents. The reported lethal dose is around 24 mg per pound of body weight, but severe toxicity can occur in much lower amounts—especially in small dogs or those with health issues. Even giving just 2-3 times the recommended dose can cause dangerous side effects.
Some factors that affect Benadryl toxicity include:
- The dog’s size and weight
- Individual sensitivity to the medication
- Any pre-existing health conditions
- Whether the dog is taking other medications
- The type of Benadryl (liquid, tablet, or gel cap)
Because human Benadryl products can have different concentrations and added ingredients, it’s always safest to double-check with a vet before giving any dose.
How Can Pet Insurance Help You if Your Dog Needs a Treatment?
Pet insurance can be a valuable tool in managing the costs of treating a dog’s veterinary expenses. By having a pet insurance policy in place, you can have peace of mind knowing that you can provide medical care for your furry companion without worrying about the financial burden. Pet insurance can help cover the costs of veterinary consultations, diagnostic tests, medications, and even specialized treatments if required.
Reimbursement
This method is the most common for pet insurance companies. You pay out of pocket for the veterinarian bill, and then the insurance company reimburses you for what’s covered under the insurance plan. The steps look like this.
- You pay the vet bill after your dog’s visit.
- You fill out the pet insurance claim form.
- Submit the claim form and other required documentation to the insurer.
- After the claim is approved, you will be reimbursed for eligible expenses.
What Does Odie Pet Insurance Cover?
Pet insurance covers various veterinary expenses, providing financial protection and peace of mind for pet owners. Here are the details of the coverage options offered by Odie Pet Insurance:
Illness & Injury Plan
The Illness & Injury Plan is an all-inclusive insurance plan designed to cover a wide range of medical needs for your pet. This plan includes comprehensive coverage for various illnesses, injuries, and veterinary services. Some of the covered items include:
- 24/7 Televet Chat
- Emergency vet visits
- Overnight hospital stays
- IV Fluids & Medications
- Medical Supplies
- Surgeries
- MRI/CAT Scans
- Rehabilitative Care
- Prescription Medications
- Gastrointestinal issues
- Laboratory Tests
Accident-Only Plan
The Accident-Only Plan is designed for pet owners seeking coverage specifically for accidents. This plan provides financial protection for emergency veterinary care resulting from accidental injuries. It includes 90% reimbursement up to $10,000 each year, with a $250 annual deductible.
Here’s an overview of the Accident-Only Plan:
- Coverage for broken bones, sprains, eye injuries, and traumatic dental fractures.
- Coverage for wounds, including bite wounds, lacerations, snake bites, and bee stings.
- Veterinary treatments covered for accidental injuries include X-rays & ultrasounds, laboratory tests, emergency care, hospitalization, CT scan & MRI, and surgery.
The Wellness Add-on Plan
The Wellness Plan is an add-on for routine care coverage you can purchase with an insurance policy. It focuses on preventive care and covers routine veterinary services. Odie has two wellness plan options available:
Basic Plan:
- Covers services such as spay/neuter and teeth cleaning, rabies vaccination, flea & tick prevention, heartworm prevention, vaccination/titer, wellness exam, heartworm test or FELV screen, blood, fecal, parasite exam, microchip, urinalysis or ERD, and deworming.
- Reimbursement up to $305 per year.
Plus Plan:
- Ideal for puppies and kittens.
- Covers services such as spay/neuter and teeth cleaning, rabies vaccination, flea & tick prevention, heartworm prevention, vaccination/titer, wellness exam, heartworm test or FELV screen, blood, fecal, parasite exam, microchip, urinalysis or ERD, and deworming.
- Reimbursement up to $535 per year.
