Trazodone vs Benadryl for Dogs

Dogs, just like humans, experience anxiety and various behavioral issues. Fortunately, there are medications available that can help manage these conditions. Two such medicines are Trazodone and Benadryl.

What are Trazodone and Benadryl?

Trazodone is an antidepressant medication that doubles up as an effective tranquilizer. It’s often prescribed for dogs experiencing anxiety, especially after surgery.

Benadryl, whose active ingredient is diphenhydramine, is an antihistamine primarily used to treat allergies in both humans and animals.

Key Uses

Trazodone for Dogs:

  1. Post-surgical anxiety management.
  2. Behavioral issues like separation anxiety.
  3. Long trips or any event that might stress your dog.

Benadryl for Dogs:

  1. Allergic reactions, including symptoms like itching or swelling.
  2. Mild sedation, especially during events like fireworks.
  3. Motion sickness relief.

Dosage: How Much to Give?

Trazodone Benadryl
Recommended Dosage 1.7 to 9.5 mg/kg every 8 to 24 hours 1 mg/lb every 8 to 12 hours
Peak Dosage (study) 8.0 to 30.9 mg/kg/day Typically not exceeded beyond standard dose

Side Effects: What to Watch Out For


  1. Sedation or lethargy.
  2. Diarrhea or vomiting.
  3. Increased anxiety or restlessness.
  4. Panting.


  1. Drowsiness.
  2. Dry mouth.
  3. Urinary retention.
  4. Increased heart rate.

Interactions and Precautions

  • Avoid giving either medication with alcohol.
  • Some dogs might have an allergic reaction to Benadryl. Symptoms include vomiting, diarrhea, or a rapid heartbeat.
  • Fatal diphenhydramine poisoning, although rare, is possible. Always follow recommended doses.
  • Trazodone can interact with other medications. Consult your vet if your dog is on any other drug.

The Final Takeaway

While both Trazodone and Benadryl can act as sedatives, their primary functions differ. Trazodone is generally prescribed for anxiety and behavioral issues, while Benadryl is often the go-to for allergies and mild sedation.


Q: How do I monitor my dog after administering Trazodone or Benadryl?

A: Observe your pet closely for a few hours after giving the medication. Watch for any abnormal behavior, excessive sedation, difficulty breathing, or signs of an allergic reaction such as swelling or hives. It’s also a good idea to ensure they have access to fresh water, as both drugs can cause dry mouth in some pets.

Q: Can puppies or senior dogs take Trazodone or Benadryl?

A: While both medications can technically be administered to dogs of any age, the effects may vary. Puppies and senior dogs may have different metabolic rates and sensitivities. Always adjust dosages based on a vet’s recommendation and monitor for any exaggerated side effects.

Q: Will long-term use of these drugs have adverse effects on my dog?

A: As with any medication, prolonged use can have potential implications. Long-term use of Trazodone might lead to liver or kidney concerns. Benadryl, when used repeatedly, may cause urinary retention issues or potential heart rate abnormalities. Periodic health check-ups and blood tests are advised for dogs on prolonged medication.

Q: Can these drugs impact my dog’s appetite or weight?

A: Some dogs might experience a reduced appetite when starting on Trazodone, leading to potential weight loss. On the other hand, the sedative effect of Benadryl might reduce a dog’s activity level, which, combined with normal feeding, could result in slight weight gain. It’s essential to monitor your dog’s eating habits and adjust their diet or medication as needed.

Q: Are there any natural alternatives to these medications?

A: Yes, there are natural alternatives that can be explored. For anxiety, products with ingredients like valerian root or chamomile might help. For allergies, natural supplements containing quercetin or omega-3 fatty acids can offer relief. However, the efficacy of natural remedies can vary, and they should be considered supplementary rather than primary treatments.

Q: If my dog accidentally consumes an extra dose, what should I do?

A: If your dog ingests more than the recommended dose of either Trazodone or Benadryl, it’s essential to contact your vet or an emergency animal clinic immediately. Overdose symptoms might include severe lethargy, difficulty breathing, or a marked change in behavior.

Q: Can Trazodone or Benadryl interact with other commonly prescribed dog medications?

A: Yes, both can have interactions. For instance, Trazodone can amplify the effects of other sedatives or interact with medications affecting serotonin levels. Benadryl can also enhance the effects of other anticholinergic drugs or medications affecting the central nervous system. It’s crucial to provide your vet with a full list of any medications or supplements your dog is taking.

Q: Are there specific breeds that may have adverse reactions to these medications?

A: While most drugs are generally safe across breeds, some breeds may have heightened sensitivities. For example, Collies and related breeds might metabolize drugs differently due to a mutation in the MDR1 gene. Always inform your vet about your dog’s breed and any known genetic predispositions.

Q: Can weather or environmental changes affect how my dog reacts to Trazodone or Benadryl?

A: Environmental factors, like extreme temperatures, can influence how a dog metabolizes medications. For instance, in hot conditions, a dog may become more dehydrated, possibly intensifying the sedative effects. Always ensure your dog is in a comfortable environment and has access to water when administering these drugs.

Q: My dog has a pre-existing health condition. Is it safe to administer these medications?

A: Dogs with certain health conditions, such as liver or kidney diseases, might process Trazodone or Benadryl differently. Additionally, dogs with cardiac conditions or glaucoma may face heightened risks. It’s imperative to discuss your dog’s full medical history with your vet before starting any new medication.

Q: Will these drugs affect my dog’s mood or personality?

A: Both Trazodone and Benadryl can cause drowsiness, which might make your pet seem more lethargic or less playful. Some dogs might also exhibit temporary mood changes, such as increased irritability. It’s important to note any behavioral changes and discuss them with your vet if they persist.

Q: Are there any immediate side effects I should be aware of post-administration?

A: Post-administration, watch for signs of excessive drooling, coordination issues, or digestive upset like diarrhea or vomiting. While these side effects are uncommon, they can occur and warrant immediate veterinary attention.

Q: Can these drugs be given before a potentially stressful event, like a thunderstorm or fireworks?

A: Yes, both Trazodone and Benadryl can be administered preemptively to help alleviate anxiety triggered by specific events. However, ensure you’re following vet-recommended dosages and timings.

Q: What should I do if I miss giving a scheduled dose?

A: If a dose is missed, give it as soon as you remember. However, if it’s close to the next scheduled dose, skip the missed one and continue with the regular schedule. Avoid giving a double dose.

Q: How should these medications be stored?

A: Store both Trazodone and Benadryl in a cool, dry place away from direct sunlight. Avoid areas of high humidity, like bathrooms, to maintain the drug’s efficacy. Always keep them in their original packaging to avoid any mix-ups.

Q: Is it safe to administer human formulations of these drugs to my dog?

A: While the active ingredients are often the same, the concentrations, additives, or other ingredients in human versions might differ. It’s always safer to use formulations specifically designed for pets. Before using any human medication, always consult your veterinarian.

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