What do vets prescribe for itchy dogs

Are you searching for everything you need to know about allergy medicine for dogs? Help is here. Integrative veterinarian Dr. Julie Buzby guides you through the signs, symptoms, and treatment options for canine allergies, including the latest on newer allergy medications such as Apoquel® and Cytopoint®.

While allergies are a very common problem in dogs, that doesn’t make it any easier for you or your beloved canine companion who is suffering.

Thankfully, now veterinary medicine has more to offer our itchy canine companions beyond Benadryl® and prednisone, the “go-to” allergy medicines for dogs in prior decades. There are newer veterinary-prescribed medications like Apoquel and Cytopoint that can quickly quell the itch.

By the end of this article, you’ll have a comprehensive list of nine solutions for dogs with allergies that includes Benadryl, Apoquel, and Cytopoint. Read on or jump to a specific topic by clicking any of the headlines in the Table of Contents below.

What are dogs allergic to?

Before we can talk about some strategies to manage allergies in dogs, first we need to establish the types of allergies dogs suffer from. Dog allergies are broken into three main categories:

1. environmental allergies
2. food allergies
3. flea allergies

1. Environmental allergies in dogs

Environmental allergies, also known as seasonal allergies, atopy, or atopic dermatitis, are exactly what the name would indicate — allergies to components of your dog’s environment. The most common environmental allergens include:

• tree pollen
• weed pollen
• grass pollen
• dust mites
• mold and mildew

While these are the most common, dogs can also be allergic to other environmental substances.

2. Food allergies in dogs

Food allergies, also known as cutaneous adverse food reaction (CAFR), occur when your dog’s immune system sees foods or ingredients as an allergen. There are a variety of foods that have been implicated in food allergies in dogs. The most common culprits are beef, chicken, lamb, and wheat.

3. Flea allergies in dogs

Dogs with flea allergies are not allergic to the presence of the fleas themselves but to the flea’s saliva that is deposited in the skin when it bites the dog. This means it only takes a few flea bites to make a flea-allergic dog significantly itchy.

Why your veterinarian may need to treat with a combination of medications

To further complicate matters, a dog may suffer from one, two, or all three of these types of allergies. The symptoms of these allergies have a cumulative effect, which is why your veterinarian may treat your dog with a combination of allergy medications for dogs, especially if your dog has more than one type of allergy. Sadly, there is no single “magic bullet” that works in all cases all the time.

How allergies impact your dog’s quality of life

Dogs who suffer from moderate to severe allergies often scratch constantly, lick their paws obsessively, and battle one ear infection or skin infection after another. In short, quality of life ebbs for these itchy dogs. They are too busy scratching and licking to fully enjoy the simple pleasures of dogdom.

This was the case for Zachory, a Chow mix who needed relief from allergies.

Taming allergy flare-ups in a senior dog

Recently, I met Zachory—a 65-pound Chow mix who had allergies. On top of that, he was fragile, suffering from back pain, hind end weakness, and intervertebral disc disease in his neck.

His mom wisely realized that contorting his body in unnatural positions to scratch himself all day was the last thing he needed to be doing. She knew he needed relief from his environmental allergy symptoms, which were at their worst in the spring.

Like many dogs with allergies, he exhibited many classic symptoms included on the list below.

Symptoms of allergies in dogs

• Itchy ears that are prone to infections
• Licking or gnawing at feet and legs
• Incessant scratching of the armpits, belly, face, base of the tail, or seemingly everywhere
• Red, irritated skin that is prone to infections
• Frequently attempting to rub the face or body against the floor
• Less commonly, a dry cough or other respiratory symptoms

For years, when Zachory’s allergies “flared up,” his mom would take him to the vet for a steroid injection. (More to come about how steroids can yield miraculous results, but the body pays a price.) In Zachory’s case, his liver enzymes were on the rise, and he was now on a nonsteroidal anti-inflammatory drug (NSAID).

An important caution about NSAIDs and steroids…

NSAIDs and steroids should never be used together because of potential damage to the gastrointestinal tract (ulceration) and kidneys.

So even though Zachory came to me for acupuncture of his neck, I was excited to discuss new, better, and safer options for treating his allergies. We worked with his regular veterinarian to select and administer Cytopoint. Zachory’s injection (dosed by body weight) was pricey. However, unlike some alternatives, it should keep him symptom-free for about a month.

Thankfully, Cytopoint won’t interfere with his other medications and it has worked beautifully for him! Mom described it as a huge relief for both of them.

Why dogs suffer from allergies

If your dog suffers from allergies like Zachory did, there are solutions! But before we jump into treatment options, it’s important to understand why allergies happen in the first place.

Uncovering the role mast cells play in allergies

In humans, the cells that mediate allergies—called mast cells—are predominantly located in the upper respiratory tract, which also happens to be the location that most of our seasonal allergy symptoms center around. However, for our canine companions, this is not the case.

In dogs, the allergy-mediating mast cells live in high concentrations in the skin. (Remember, ears are just an extension of the skin.) Thus, dogs are more likely to have seasonal allergy symptoms that center around the skin and ears.

Mast cells are a type of white blood cell that is made in the bone marrow then travels to the tissues of the body (skin, GI tract, respiratory tract, etc). They help protect the body against foreign invaders.

Mast cells look very distinct under a microscope. They are filled with tiny granules which contain several active substances, the most well known of which is histamine. Don’t forget about histamine because it will come into play when we look at allergy therapies — namely antihistamines.

When mast cells sense something they see as a potential threat—in this case an allergen, like pollen—they become activated and start “degranulating.” This is the process of dumping the granule contents (histamine and other immune system molecules) into the surrounding tissue. A chain of events ensues which summons the rest of the immune system army (aka the reinforcements) and causes allergy symptoms.

Now that we’ve established the role the mast cell plays in dog allergies, let’s discuss allergy medicines for dogs and supportive therapies.

Benadryl, Apoquel and 7 more options for soothing allergies in dogs

1. Antihistamines like Benadryl and Zyrtec

ANTI-histamines, such as diphenhydramine (Benadryl®), certirizine (Zyrtec®), and hydroxyzine, are commonly taken by humans to treat allergy symptoms and can be used for dogs as well. These medications work by preventing histamine from binding to cells and exerting its effects.

The benefits of antihistamines are that they are cheap and may help with mild environmental allergies in dogs. The downside is that they are typically unimpressive in their effectiveness for more significant environmental allergies in dogs. Therefore, they usually need to be used in combination with other medications to control symptoms.

2. Oclacitinib (Apoquel): a newer allergy medication for dogs

Oclacitinib (Apoquel) is a relatively new medication for treating allergies in dogs. (The FDA approved it in 2013.) Apoquel works by blocking the action of JAK1 and JAK3, molecules normally used to transmit the “itch and inflammation signal” created in response to an allergen. This translates to less itching and inflammation for your allergic dog.

Like the dog in the before and after photos below, most allergy patients respond to Apoquel very quickly. It’s highly effective in quelling the itching, as well as managing the allergies long term.

Initially, the medication is given twice a day for two weeks and then tapered to once a day for maintenance. Some dogs show an increase in symptoms when they go from the twice-a-day dose to the once-a-day dosing. If you notice your dog is becoming more itchy again, speak to your veterinarian for guidance on how to proceed.

Possible side effects of Apoquel

Like any medication, there is a risk of side effects. However, the number of dogs who experienced side effects (such as vomiting and diarrhea) was very low compared with other medications.

Because Apoquel does block a chemical signal in the immune system, there is a risk of suppressing the immune system at high doses. However, since Apoquel has a more specific target than other medications such as cyclosporine or steroids, there is a comparatively lower risk of immunosuppression.

Apoquel: full disclosure

In the interest of full disclosure, there was some concern that because of the way Apoquel works to modify the immune system, it could be linked to the development of cancer in dogs.

A study was recently published which compared the occurrence of cancer and skin masses in allergic dogs who were treated with Apoquel to allergic dogs of a similar age and breed who had never received Apoquel. This study determined that there was no significant difference in the rate of occurrence of cancer and skin masses or in the average age at death between the groups, which is reassuring.

The Apoquel product insert, however, continues to warn that it may exacerbate (worsen) cancerous conditions, and that the risks and benefits should be weighed before using it in dogs with a history of cancer.

Personally, I think it’s a valuable drug that has dramatically improved quality of life for many dogs who suffer from allergies. Although the data doesn’t indicate that Apoquel increases the cancer risk, I still prefer to play it safe and use other allergy treatments in dogs with documented or suspected cancer.

By the way, if you’d like to learn more about cancer in dogs, please listen to my podcast interview with my friend and colleague, Dr. Sue — Cancer Vet: The Myths and Misconceptions of Cancer in Dogs.

Finally, Apoquel is labeled for the management of allergies in dogs older than one year of age, which means it cannot be used in young dogs suffering from allergies.

The bottom line on Apoquel for dogs

BOTTOM LINE: Apoquel is a veterinarian favorite due to its ability to rapidly and effectively control allergies with minimal side effects. Although it should still be used with caution in dogs with cancer, a recent study indicates that it doesn’t increase a dog’s risk of developing cancer.

3. Canine Atopic Dermatologic Immunotherapeutic (Cytopoint)

An even more recent development in the management of allergies in dogs, has been the development of Cytopoint—an antibody (immune system molecule) that attaches to an itch-triggering chemical signal called IL-31. Once bound to IL-31, Cytopoint blocks the creation of further itch signals, thus offering relief to your itchy dog. It’s not a pill, but rather, is given every one to two months as an injection at your veterinarian’s office. This is great news for owners of dogs who won’t take pills .

The before and after photos below illustrate the marked improvement Cytopoint can make. The photo on the left was taken on November 25, 2020. The photo on the right was taken May 14, 2021.

Cytopoint starts working within one to two days after the injection and helps the dog for one to two months. Because it is targeting a very specific signal in the immune system, the risk of suppressing the immune system is low, so it can be used safely with other medications. 

Unfortunately, because this medication targets the chemical signal associated with the itching “feeling” instead of modifying the action of cells in the immune system, it’s not as effective as steroids or Apoquel in reducing signs of allergy-related inflammation such as red and irritated skin or swelling of the ear canals.

The bottom line on Cytopoint for dogs

BOTTOM LINE: This is the “latest and greatest” allergy medication for dogs. It is perhaps better than other available options for dogs who already have an underlying medical condition. However, it does not do as good of a job at reducing inflammation. Since a single injection lasts four to eight weeks, it can be an easy and effective solution for allergies.

4. Dog steroids for allergies

Steroids, including prednisone, dexamethasone, and triamcinolone are available in a wide variety of forms including oral liquids, oral tablets, topical medications/shampoos, and injectable medications.

They work by suppressing specific cells and chemical signals found in the immune system to dramatically reduce inflammation and itching. In fact, steroids often work like magic to provide relief for itchy dogs. (For more information on prednisone, listen to my podcast: Prednisone 101.)

Benefits of steroids as an allergy medication for dogs

The benefits to steroids include:

• Steroids work rapidly, powerfully, and are relatively inexpensive.
• Steroids are particularly beneficial in the treatment of ear infections in dogs. Here’s why: many times the swelling of the ear canal is so severe that it can be difficult to get the medication down into the ear canal to treat the infection. Because steroids reduce inflammation, they are one of the only classes of allergy medication that can open the ear canal, allowing for better treatment of the underlying ear infection.

However, and it’s a big “however,” steroids are not without side effects.  Compared with other medications discussed in this article, steroid’s side effects are relatively common and disturbing.

What are the side effects of steroids?

• Increased thirst
• Ravenous appetite
• Frequent urination
• Panting
• Muscle wasting
• Increased risk of urinary tract infections, fungal infections, mange, and bacterial infections
• Potential to cause iatrogenic Cushing’s disease in dogs, a condition in which administration of steroids, either topically or systemically, mimics naturally occurring Cushing’s disease in dogs.

The bottom line on steroids for dogs with allergies

BOTTOM LINE: Steroids are highly effective for environmental allergies (not necessarily food allergies) but super concerning for long-term use. Chronic steroid use will likely take a toll on the dog’s body, and the risks may outweigh the benefits.

5. Immunotherapy: the gold standard in treating environmental allergies in dogs

When it comes to treating environmental allergies in dogs, the gold standard is immunotherapy. Similar to “allergy shots” in people, this treatment works by slowly exposing the dog’s immune system to the allergen until the immune system no longer reacts to it. 

The immunotherapy is given as an injection under the skin once every one to three weeks or as a medication that is given under the tongue (sublingual) every 12 hours.

Benefits of immunotherapy as an allergy medication for dogs

There are many benefits of immunotherapy.  Instead of suppressing the immune system, the treatment is directly targeted to the allergens that specifically trigger that dog’s immune system. A skin test or blood test is used to determine which allergens are a problem for that dog, and the immunotherapy is customized based on that information.

Between 50% to 80% of dogs on immunotherapy show improvement in allergy symptoms after a year of treatment.

Downsides to immunotherapy as a medication for dogs with allergies

There are some downsides to immunotherapy.  First, because the immune system is being stimulated instead of suppressed, there is a low risk of a serious allergic reaction. Second, therapy is a lengthy process, usually taking between six to 12 months. Because no standard protocol exists, results can vary, and dogs may need to remain on immunotherapy for the rest of their lives to maintain control of their environmental allergies.

The bottom line on immunotherapy for dogs with environmental allergies

BOTTOM LINE: Immunotherapy can be a great tool for dogs with environmental allergies because it specifically targets the problematic allergens and has a low risk of side effects. However, it may take six to 12 months to reach full efficacy and doesn’t work in all cases.

6. Atopica as a medication to treat allergies in dogs

Cyclosporine (Atopica) works by blocking the activation of T cells, a type of white blood cell that targets specific foreign invaders, and decreasing the release of pro-inflammatory chemicals. This helps reduce the signs associated with allergies since they are mediated by the immune system’s reaction to allergens.Cyclosporine is effective for long-term management of allergic dogs and in some cases, can be used as a sole treatment for allergies.

Atopica takes about six to eight weeks before the full effects of medication are seen. Sometimes other allergy medications for dogs might need to be used to control allergy symptoms while waiting for the cyclosporine to kick in. It’s also important to note the some dogs experience undesirable side effects.

What are the side effects of Atopica?

• Vomiting and diarrhea in the first seven to 10 days of administration (Thirty percent of dogs may have this.)
• Overgrowth of the gums (gingival hyperplasis)
• Immunosuppression could lead to increased susceptibility to developing neoplasia (cancer)
• Reported increase risk of urinary tract infections in dogs and fungal infections

The bottom line on Atopica for dogs with allergies

BOTTOM LINE: Atopica can be effective at managing allergies. However, it comes with a host of side effects. This is why it has fallen out of favor in recent years as a first line allergy therapy now that Apoquel and Cytopoint have come on the market.

In addition to medications to treat dogs with allergies, there are a number of ways supportive therapies can help control allergy symptoms. Next, we’ll look at three.

7. Making diet changes to help control food allergy symptoms

Performing a food trial, which involves changing your dog to a hypoallergenic diet, can help diagnose and manage food allergies in dogs. If the allergy symptoms improve after your dog has been on the new food for six to 10 weeks, a food allergy is a likely the underlying reason for the symptoms.

Confirmation of the diagnosis comes if symptoms return within 14 days after being reintroduced to the old food or suspected allergen. Once a food allergy is diagnosed and the allergen is identified, continuing to eliminate it from the diet may help control allergy symptoms long term.

How do I choose the food for a food trial?

The goal of a food trial is to ensure that your dog is eating only food that it’s unlikely to be allergic to. This can be accomplished using a veterinary prescription diet or a homemade diet formulated by a veterinary nutritionist. 

For detailed information on homecooked diets, check out my podcast: Homecooked Diets for Your Dog with Dr. Jackie Parr.

If a commercial kibble or canned diet is going to be used, it is important to choose a veterinary prescription diet instead of an over-the-counter diet. Studies evaluating over-the-counter diets detected the presence of proteins not listed on the label due to cross-contamination during manufacturing. This means that it’s possible that an allergic patient may unknowingly continue to be fed the allergen, making it appear that the new diet didn’t help improve allergy symptoms.

Prescription diets, in contrast, are produced on a dedicated food production line that only processes the food on the label. This prevents contamination with other proteins so you can feel confident that your dog is eating only the listed ingredients.

Types of hypoallergenic diets

Hypoallergenic diets fall under two categories:

• Novel protein: These diets usually consist of a new protein, such as kangaroo, rabbit, duck, venison, etc. that your dog has never eaten before and therefore is less likely to be allergic to.

• Hydrolyzed protein: The protein source in these diets is broken down into such small pieces that the body should not mount an allergic response to the food.

Food trials can be tricky to execute

Although food trials have tremendous benefits because they can help identify and manage food allergies, they can be tricky to perform. The diets are expensive and can be labor intensive if a homemade diet is used.

The new diet needs to be fed for six to 10 weeks with no additional treats, table scraps, or protein sources. It is critical that every member of the family and even neighbors are on the same page regarding the diet trial.

Taking these precautions will ensure that no one accidentally feeds your dog table scraps or treats during this period. Your dog sneaking cat food, stealing a snack from the toddler, or conning the neighbor out of a treat can be enough to make the food trial appear to have been unsuccessful in decreasing allergy symptoms. In reality, however, your dog was still eating the allergen.

Also, talk to your veterinarian about heartworm and flea and tick prevention during the diet trial. The flavoring in some medications can negate the test as well.

The bottom line on food trials for dogs with food allergies

BOTTOM LINE: Eliminating allergens from your dog’s diet is by far the best way to manage food allergies. Although it can be expensive and cumbersome to carry out a food trial and tightly control your dog’s diet long term, this is the single best way to give your food-allergic dog some relief. All other medication and treatment options pale in comparison.

8. Essential fatty acids as a supportive therapy for treating allergies in dogs.

Essential fatty acids (EPA/DHA) help decrease inflammatory signals in the body and improve the skin barrier. This can help reduce the amount of medication, particularly steroids or antihistamines, needed to control allergies.

It’s important to point out that this is an additional therapy. In other words, it is ineffective as a single therapy to control allergies and itching but can be useful in conjunction with the other therapies discussed here. Also, it may take up to two months to see improvement.

Essential fatty acids (Omega 3s) come in oils or capsules that can be added to your dog’s food and are relatively safe and relatively inexpensive. For more information on the importance of careful storage of Omega 3s and to learn which brand I recommend, read my article: The Benefits of Omega-3 Fatty Acids for Your Dog.

The bottom line on essential fatty acids for dogs with allergies

BOTTOM LINE: Essential fatty acids make a great adjunctive therapy for dogs with allergies, but they are not sufficient as a sole means of allergy control.

9. Environmental changes to help reduce allergy symptoms in dogs.

As discussed in the section on the types of allergies, there are often multiple factors contributing to flare ups, which gives opportunity for various avenues of control. Treatments that can work synergistically with allergy medicine for dogs to help reduce symptoms include:

Flea Prevention

In addition to spreading diseases like Bartonella, fleas can contribute to allergy flare-ups in dogs. If your dog is flea allergic, all it takes is the saliva from the one bite of a flea to trigger an allergic flare-up.

Therefore, it is important to keep your dog on year-round flea prevention. Flea preventatives come in oral and topical treatments. Please talk with your veterinarian about which preventative is best for your dog.

Medicated shampoo for dogs

Medicated shampoos can be used to treat fungal and bacterial infections as well as reduce the number of allergens that build up in your dog’s fur.  Most protocols involve bathing your dog one to two times per week and letting the shampoo sit for a contact time of 10 to 15 minutes before rinsing it off. Talk with your veterinarian about which shampoos and bathing frequency would be best for your dog.

Also, simply wiping a dog’s body and paws down with a cold, wet washcloth after being outdoors will remove allergens from the coat and can help reduce allergy symptoms for dogs with environmental allergies.

Vacuuming/washing pet beds

Dust mites are a common source of allergens in humans and pets. Although it’s difficult to completely eliminate dust mites from the environment, routine vacuuming, and washing dog bedding in hot water will help reduce the number of dust mites in the environment.

Bottom line on environmental changes for dogs with allergies

BOTTOM LINE: Environmental changes can help reduce the allergen load on and around your dog, thus decreasing the allergic reaction. When it comes to allergies, every little bit helps, but these changes are not meant to be a stand-alone management tool.

Infographic: Allergy medicine for dogs

As a summary, the infographic below is your quick reference guide to understanding how each allergy treatment option works, the dosing frequency, and the pros and cons.

Partner with your veterinarian to help you find the best allergy medicine for your dog

Thankfully, there are a lot of options today for allergy medicines for dogs. Please talk with your veterinarian about which medication options may be best for managing allergies in your dog. Your beloved canine companion will thank you for it.

What questions do you have about allergy medicine for dogs?

Please comment below.