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Ask the Vet

Allergy Medicine for Diabetic Dogs: What Is Safe for Them to Take (Vet Answer)

Dr. Samantha Devine
Written and fact-checked by Dr. Samantha DevineVet Approved
Dr. Samantha Devine
Reviewed & Fact-Checked byDr. Samantha DevineDVM (Veterinarian)
Dr. Samantha Devine is a practicing veterinarian who enjoys caring for animals and sharing her knowledge with pet owners. Preventative care, ranging from nutrition to vaccination, is her specialty and passion!View authorThe information is current and up-to-date in accordance with the latest veterinarian research. Learn more
Updated on June 17, 2026
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Owner giving medicine in a pill to his dog

Your pup is itchy, and it's keeping you up—no wonder you're interested in allergy medication for your dog. The question is, what kind of allergy medication can your dog take because it's diabetic? Let's look at some allergy medications and see what your furry family member can take to help you both get some sleep tonight.

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What Is an Antihistamine?

An antihistamine is an allergy medication that helps block the effects of histamine on the body. These medications come in many forms and tend to be effective at controlling many allergy signs and symptoms.

Unfortunately, in dogs, signs of allergies aren't just caused by histamine; they're also caused by inflammatory cells like cytokines. Most dogs don’t have itchy, watery eyes as part of their allergy manifestation; they tend to develop ear infections and lick their paws. As such, many dogs are not well controlled by antihistamines. One study showed that only 27% of dogs responded well to antihistamines1.

The most commonly used antihistamines in dogs are human medications that veterinarians use off-label.

Some of these that are safe for diabetic dogs include:

  • Diphenhydramine (Benadryl)
  • Cetirizine (Zyrtec)
  • Loratadine (Claritin)
  • Chlorpheniramine (Chlor-Trimeton)
  • Hydroxyzine (Atarax)

A veterinarian might recommend a newer medication to control your dog's allergies that isn't an antihistamine.

These medicines include:

  • Apoquel
  • Cytopoint
  • Atopica

Many dogs need a multipronged approach to treat allergies. These treatments can include topical products, such as shampoos. Many veterinarians recommend omega-3 fatty acid products, such as Welactin, to help decrease inflammation and itchiness.

Image Credit: SeventyFour, Shutterstock
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How Are Allergy Medications Given to Dogs?

Most allergy medications, especially antihistamines, are given to dogs in tablet form. These are generally unflavored tablets, but some are available in a liquid formulation.

Apoquel is only available as a tablet, but the company has made a chewable tablet to help encourage dogs to take the medication. Cytopoint is an injection that the veterinarian administers every 4 to 8 weeks. Atopica is usually used in a capsule formulation, but some small dogs can utilize the liquid cat version.

Antihistamines do not usually have interactions with insulin and can typically be given at similar times. Atopica and Cytopoint manufacturers do not report any interactions with insulin treatment either, but it is best to follow the veterinarian’s guidelines to ensure the safest and most effective treatment plan for your dog.

Talk to a veterinarian about whether an antihistamine or other allergy medication might be effective for your dog's allergy signs.

What Happens if You Miss a Dose?

If you miss a dose of your dog's allergy medication, give it when you remember. Do not double up on doses, so if it's close to the time of the next pill, consider the dose missed.

Image Credit: Liudmyla Guniavaia, Shutterstock
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Potential Side Effects of Antihistamines in Dogs

While not all dogs respond effectively to antihistamines, they are relatively safe, even for diabetic dogs. The most common side effect is drowsiness, commonly seen with Benadryl and diabetes or any other condition.

Antihistamines are generally not used in pregnant or nursing dogs because of the possible risk of side effects. Working dogs should not be given an antihistamine without talking to a veterinarian because of the drowsiness factor: you don't want your working dog sleeping on the job or having its reflexes compromised.

Some dogs will develop paradoxical excitement when antihistamines are used. Ever get the zoomies with Benadryl? Well, some dogs do, too.

The veterinarian may suggest using an antihistamine over a steroid if your dog is a diabetic. Steroids are usually contraindicated with diabetic dogs because they have the tendency to cause insulin resistance2. In fact, chronic steroid usage sometimes causes diabetes in our dogs and cats.

Do not use an antihistamine with a decongestant in it, such as Claritin-D Or Zyrtec-D. These medications can be dangerous for your dog to take. You should also avoid any product with xylitol in it due to the risk of hypoglycemia and liver damage.

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Frequently Asked Questions

Are there allergy supplements I can give my diabetic dog?

In most cases, pet supplements are safe to use in your diabetic dog. If they are treats, you'll need to factor those into your dog's caloric intake for the day, which can impact their glycemic regulation.

Fish oils like Welactin are commonly used for allergy sufferers and are often well tolerated.

Probiotics may even be beneficial for allergic dogs. The gut makes up a large portion of the immune system, and probiotics can help keep this organ healthy and regulate the bacteria that live in it.

Can diabetic dogs have Apoquel or Cytopoint?

Diabetic dogs can generally take allergy medications like Apoquel and Cytopoint. These medications are likely more effective than antihistamines for your dog, so you should discuss them as an option with a veterinarian.

Image Credit: Ground Picture, Shutterstock

What dogs should not take Apoquel?

Dogs with parasitic skin diseases like Demodex should not take Apoquel. It may also worsen pre-existing cancers, so typically, dogs with cancer are not prescribed this medication.

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Conclusion

If you have an allergic dog, talk to a veterinarian about options. Your dog will likely need more than one treatment, but antihistamines can help control signs of itchiness.

Sources

Featured Image Credit: Creative Cat Studio, Shutterstock

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Dr. Samantha Devine DVM (Veterinarian)
Authored by

Dr. Samantha Devine DVM (Veterinarian)

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