Over-the-counter (OTC) antihistamines for dogs include diphenhydramine (Benadryl), loratadine (Claritin), and cetirizine (Zyrtec). These three medications can provide relief from dog allergy symptoms and may be the only treatment needed for some lucky dogs. Other dogs may still need prescription medications to treat their allergies long term.
Seasonal Allergies in Dogs
Environmental allergies, or atopy, can be as miserable for dogs as they are for humans. But humans get runny eyes and sneezing fits and dogs itch. Remember: Fleas cause your dog to itch, too, so be sure you check for a flea infestation, which will need a flea treatment.
Dog allergy symptoms include:
- Frequent scratching and chewing of skin
- Licking and chewing at paws
- Scratching ears
- Chronic ear infections
- Red, irritated skin or ears
- Flaking skin
- Licking and chewing at hind end
- Rashes and sores
- Darkening of the skin
- Inflammation around the eyes
Allergies cannot be cured and will require lifelong management. Some dogs only require treatment during specific times of year, but others may need treatment year-round.
Safe OTC Allergy Meds for Dogs
If your dog is itchy and scratchy, and you are sure you are dealing with an allergy, you may decide to your own medicine cabinet for home remedies for dog allergies. The three primary antihistamines used by humans with allergies are also safe for dogs. For many dogs, these medications will not be able to control allergy symptoms alone, but they can provide some relief until you are able to get a vet appointment. These medications may play a role in long-term management.
NOTE: Always check the inactive ingredients on any product for xylitol or birch sugar. This artificial sweetener may be added to human medications, but xylitol is extremely toxic to dogs.
Benadryl
Diphenhydramine (Benadryl) is safe for dogs and a solid first option to try. The Benadryl dosage for dogs is 1 milligram (m) per pound, meaning a 50-pound dog will get 50 mg. Diphenhydramine is usually available in 25 mg tablets, so this dog would get two tablets. Benadryl is usually given twice a day and can make dogs sleepy.
Benadryl is also available as a liquid, which can be easier to dose for small dogs.
Claritin
Loratadine (Claritin) is safe for dogs and only needs to be given once a day. The dosage for dogs is 1 mg per four pounds, meaning a 50-pound dog will get 12.5mg. Loratadine is usually available in 10 mg tablets, so this dog would get one tablet. To get your dog’s dose, divide his weight by four. Then divide that by 10 to get the number of tablets.
Zyrtec
Cetirizine (Zyrtec) is safe to give your dog and is given twice a day. The Zyrtec for dogs dosage is 1 to 2 mg per four pounds, meaning a 50-pound dog will get 12.5 to 25mg. Zyrtec is usually available in 10 mg tablets, so this dog would get one to two tablets. It is generally best to start with the lower dose. To get your dog’s dose, divide his weight by four. Then divide that by 10 to get the number of tablets.
Side Effects of OTC Allergy Meds in Dogs
Over-the-counter antihistamines are generally well-tolerated by dogs, but side effects are possible. Things to watch for are drowsiness, sedation, poor appetite, vomiting, or diarrhea.
If your dog seems sick after taking any medication, call your vet.
When to See a Vet for Dog Allergies
Allergies are not emergencies, but we strongly recommend scheduling a veterinary appointment sooner than later. OTC antihistamines may help in mild cases, but there are more robust prescription options available that may provide your dog better relief. Your veterinarian can also make sure that your dog’s allergy meds don’t conflict with any other medications or supplements he may be taking.
