Apoquel For Dogs – Side Effects Of Apoquel For Dogs

Medical review by K9 Healthcare Council of America (K9HCA). Intended for educational purposes only. Always seek medical advice from your veterinarian.

Apoquel For Dogs

By their very nature, dogs tend to lick, scratch and chew themselves! But if your dog is suffering from unrelenting itching behavior due to skin allergies, relief can’t come soon enough for you and your dog to get back to a life of doing what you love.

Unfortunately, when dermatitis causes an itch that just won’t go away, your dog’s repetitive scratching & chewing behaviors can eventually damage your dog’s skin–causing painful skin lesions.

This pattern sets up a vicious cycle of irritation which is hard to break; and even harder to treat.

If your dog is constantly itching, scratching or biting his skin, it might be time for serious medical intervention. Apoquel is often prescribed by veterinarians for dogs allergies, but what are the side effects of Apoquel for dogs?

Apoquel For Dogs Allergies

Oclacitinib, brand name Apoquel®, is an FDA approved immune suppressant drug often prescribed by veterinarians for dogs to control the itch and inflammation associated with allergic and atopic dermatitis.

Apoquel is used to treat itching in dogs resulting from a variety of causes including flea allergy, food allergy, contact allergy and canine Atopic Dermatitis.

Apoquel is ideal for both short or long-term treatment for pruritus (intense itching) and can help to offer relief without many of the side effects associated with steroids. In most dogs, Apoquel starts to relieve unpleasant symptoms within 4 hours, and effectively controls itching within 24.

However, the antipruritic effects of the Apoquel wear off quickly, within 12-24 hours, so the medication needs to be given daily in most cases. In addition, Apoquel is only intended for dogs over 12 months in age and weighing more than 6.6 lbs.

Apoquel for dogs allergies. Side effects of apoquel for dogs
Apoquel for dogs: a cautionary tale: Apoquel is the latest in a line of drugs used to help dogs with itchy skin caused by allergies or atopic dermatitis but comes with serious health concerns.

How Does Apoquel Work?

When a dog suffers from allergies which cause dermatitis, there are two parts to treating them:

  1. Identifying the allergen so they can be protected from future exposure to it, and
  2. Relieving the discomfort of their symptoms in the meantime.

Veterinarians will recommend Apoquel for the second part – relieving the discomfort of itching.

Apoquel is an oral tablet that works differently than other allergy medications like steroids, antihistamines or cyclosporine for dogs. Apoquel goes straight to the source to help relieve itching and inflammation at its core—addressing the underlying cause of irritation to soothe allergic reactions.

In simple terms, Apoquel changes how the immune system reacts.

But let’s break that down a little bit more. Apoquel is an FDA approved immune suppressant drug in the selective Janus kinase (JAK) inhibitor class, which targets pruritogenic (itch creating) cytokines. The main active ingredient in Apoquel is oclacitinib maleate.

Specifically, when oclacitinib enters the bloodstream, it blocks particular enzymes called Janus kinases. They’re the real troublemakers when it comes to the itchiness and inflammation associated with atopic dermatitis.

Apoquel works to control pruritus by inhibiting primarily JAK-1 and JAK-3 signaling that would normally occur when a cytokine binds to a receptor on the surface of the cell. This includes blocking the effects of inflammatory cytokines released from activated lymphocytes (IL-2, -4, -6, -13) as well as IL-31, a cytokine directly involved in the sensation of itch.

side effects of apoquel in dogs
Illustration of lymphocytes attacking a cancer cell. Natural killer cells are a type of lymphocyte that destroys cancer cells but are inhibited by immune suppression action of Apoquel.

Unfortunately, while Apoquel can reduce your dog’s itching skin and make his allergy more tolerable, what it means long-term is the very serious adverse effect of demolishing essential functions of your dog’s internal disease-fighting immune systems.

What are the Benefits of Using Apoquel for Dogs?

Apoquel offers various benefits for dogs suffering from allergies, with the primary advantage being the temporary relief it provides from the incessant and distressing symptom of itching. As soon as it is administered, Apoquel starts to take effect within just four hours, offering quick relief to your dog. It works effectively to control and alleviate itching within 24 hours, allowing your furry friend to experience much-needed relief from their allergies.

Side Effects of Apoquel for Dogs

Apoquel is the latest in a line of drugs used to help dogs with itchy skin caused by allergic or atopic dermatitis. Released in 2013 by Zoetis, the animal medicine arm of pharmaceutical giant Pfizer, Apoquel was developed as an alternative for dogs who didn’t benefit from earlier drug therapies or who couldn’t tolerate their side effects.

So far no anti-itching drug (including Apoquel) has been created which is completely effective or completely free from side effects.

What Are the Potential Side Effects of Apoquel? 

You may have tried other treatments to relieve your dog’s allergic itch. So, getting the right treatment early on can help avoid unnecessary suffering and the out-of-pocket expenses associated with treatments that just don’t do the trick.

Adverse reactions reported in a masked field study included diarrhea, vomiting, anorexia, new cutaneous or subcutaneous lumps, and lethargy.

apoquel side effects
Apoquel side effects include vomiting, diarrhea and severe lethargy. APOQUEL may also increase the chances of developing serious infections or cause existing parasitic skin infestations or pre-existing cancers to get worse.

In most cases, diarrhea, vomiting, anorexia, and lethargy spontaneously resolved with continued dosing.

Common adverse reactions seen in dogs taking Apoquel:

  • Vomiting
  • Diarrhea
  • Depression/lethargy
  • Anorexia
  • Pruritis
  • Elevated liver enzymes ALT & ALKP
  • Drug interactions
  • Rapid Panting
  • Trembling
  • Seizures
  • New cutaneous / subcutaneous lump

Low numbers of dogs in studies with Apoquel developed demodicosis (skin mites), neoplasia (abnormal cell growth), pneumonia, bloody diarrhea, skin and ear infections, UTIs, and histiocytomas. Interestingly, in early studies, a few dogs developed polydipsia (increased drinking), increased appetite, and aggression, similar to what may be seen with steroids.

But the biggest concern about Apoquel is that it may exacerbate neoplastic conditions and increase susceptibility to infection, including demodicosis (mange).

Apoquel Interrupts Life-Sustaining JAKs

Apoquel’s mechanism is to interrupt JAKs … and prevent them from working properly.

According to the manufacturers description of Apoquel, dogs taking Apoquel had decreased leukocytes (neutrophil, eosinophil, and monocyte counts) and serum globulin, and increased cholesterol.

Essentially, Apoquel undermines your dog’s immune system from ensuring adequate inflammatory response measures to fight against tumor formation.

JAK’s are key elements in controlling both growth and development and policing (monitoring) of cancer cells. They are responsible for forming white & red blood cells and ensuring antibody-producing B-cells and T-cell surveillance within your dog’s body to find and destroy abnormal cells that have become cancerous–before they become tumors.

These JAK’s communicate with each other and share information to keep your dog’s body healthy. By preventing JAKs from working, Apoquel undermines your dog’s protective immune system and cancer protection response. Without JAKs your dog’s immune system cannot function correctly.

JAK-1 is a crucial messenger. It’s needed to destroy invading parasites, fungi, bacteria and viruses. JAK-2 is central to the production of bone marrow stem cells. These cells then become red and white blood cells and platelets. Your dog’s antibody system (B cells) and its killer-cell system (T cells) need JAK-3 in order to function properly at full capacity.

Apoquel Dosage for Dogs

Apoquel is dosed according to your dog’s weight. Remember, Apoquel is ONLY for dogs 6 lbs and over; so the recommended initial dosage for dogs 6.6 – 9.9 lbs is 1/2 of a 3.6 mg tablet.

The dosage for dogs 10-14.9 lbs. is ½ of a 5.4 mg tablet, twice daily. The dosage for dogs 15-19.9 lbs. is one 3.6 mg tablet twice daily.

The dosage for dogs 20-29.9 lbs. is one 5.4 mg tablet twice daily. The dosage for dogs 30-44.9 lbs. is ½ of a 16 mg tablet twice daily.

The dosage for dogs 45-59.9 lbs. is two 5.4 mg tablets twice daily. The dosage dogs 60-89.9 lbs. is one 16 mg tablet twice daily.

The dosage dogs 90-129.9 lbs. is 1½ 16 mg tablets twice daily. The dosage for dogs 130-175.9 lbs. is two 16 mg tablets daily.


Apoquel should not be given to dogs younger than 12 months or those with serious infections. Do not use Apoquel in breeding, pregnant, or lactating dogs. APOQUEL may increase the chances of developing serious infections and may cause existing parasitic skin infestations or pre-existing cancers to get worse.

And for concerned pet parents who have tried multiple therapies without success, APOQUEL has still not been tested in dogs receiving other medications, including corticosteroids and cyclosporine commonly used to treat skin conditions in dogs.

Alternative To Apoquel for Dogs Allergies

If your dog is rolling, rubbing and scratching his skin excessively, has recurrent ear problems (such as head shaking or ear discharge with odor), or skin rashes and hair loss, you need to find allergy relief…FAST!

Natural Alternative to Apoquel for Dogs

For those pet parents who are looking for a more natural way to treat their dog’s allergy symptoms without the worry of destroying their dog’s immune response system, there is new evidence that CBD (Cannabidiol) from full spectrum hemp can help alleviate your pet’s itching and scratching allergy symptoms without the negative immune suppressive side effects.

CBD oil for dogs allergies
Hemp CBD oil is a superior natural treatment alternative to relieve symptoms of itching for dogs with allergies & atopic dermatitis.

Dog Allergies Medicine – CBD For Pet Allergies

Academic research centers in the United States are currently studying the effects of using CBD-rich products to treat a wide range of canine conditions including chronic pain, cancer, diabetes, cardiovascular disease, as well as effective therapeutic intervention for canine allergies.

Cannabidiol (CBD) is a non-intoxicating, non-psychogenic component of the hemp plant that holds enormous therapeutic potential for our pets with Atopic Dermatitis.

CBD oil as a treatment for Allergic Dermatitis seems to work by modulating the cellular inflammatory response. In particular, CBD acts as a neuro-immune modulator, or signaling molecule, for communication between cellular structures, tissues and organ systems specifically involved with inflammation & allergic responses.

Specifically, Cannabidiol curbs inflammation by suppressing the infiltration and functional activity of T cells and macrophages localized at the site of inflammation; thereby preventing the cascade of cellular immune/allergic responses that result in your dog’s sorrowful itching & scratching behavior.

Previous studies concluded that endocannabinoid receptors are “up-regulated” in dogs with atopic dermatitis (skin allergies), which suggests they can respond to this inflammatory condition by producing chemical substances that can reduce inflammation–the major cause of the symptoms of allergies.

apoquel for dogs side effects
CBD is a natural treatment for dogs with environmental (indoor and outdoor) allergens, such as pollen, dust mites, and mold.

But just like other herbal medicines, CBD may not have an immediate, instantaneous effect on this condition. By using a daily CBD phytonutrient supplement it’s possible to suppress or at least moderate the agonizing effects of chronic inflammation for animals who suffer from skin inflammation “hot-spots” and allergic dermatitis.

Better still, the positive effects of CBD for dogs extend well beyond the physical care of your pet.  Full spectrum CBD oil is a safe, holistic pet food supplement that can also improve mental, emotional and behavioral related canine issues like noise phobias and Separation Anxiety as well as Musculo-skeletal & mobility problems like osteoarthritis.

Although CBD seems to be a potent new therapy to positively influence the inflammatory response and eliminate the tormenting symptoms of allergies in our furry friends; using CBD for K9 allergies is far more effective when used in conjunction with dietary changes and family home-environment improvements to avoid needless contact exposure to potential external allergens that are at the root-cause your dog’s unnecessary itching symptoms.

What are Some Natural Remedies for Fleas in the Home?

There are several natural remedies that can help to combat fleas in your home without resorting to chemical treatments. One way to prevent flea infestation is by using regular flea medication or trying natural flea sprays on your dog. These products can help repel fleas and minimize the chances of your pet getting bitten.

Additionally, you can take measures to protect your home from fleas and other pests. Sprinkling borax or a powder called diatomaceous earth in the cracks and crevices of your house can be an effective way to control fleas indoors. These substances work by dehydrating and killing the fleas, breaking their life cycle and preventing infestation.

By using these natural methods, you can help keep your home flea-free and provide relief for your dog from the intense itching and discomfort caused by flea bites. Remember to consult with a veterinarian for the most suitable natural remedies for fleas based on your pet’s specific needs.

FAQ’s About How to Improve Your Dog’s Immune System

How can I normalize my dog’s immune response?

Normalizing your dog’s immune response can be supported by providing them with a healthy diet and probiotics. A simple and nutritious diet, with minimal ingredients, additives, and preservatives, can help minimize the chances of allergies that might compromise the immune system. Additionally, giving your dog probiotics can contribute to establishing a balanced and robust gut flora, which plays a crucial role in immune system regulation and response.

How can I improve my dog’s gastrointestinal health?

Improving your dog’s gastrointestinal health can be achieved by giving them probiotics. Probiotics help to establish and maintain healthy gut flora, which has been linked to better immune responses. It is important to note that results may take a few weeks to become noticeable, so consistent use of probiotics is necessary to see the desired improvement in your dog’s gastrointestinal health.

How can I prevent food allergies in my dog that may affect their immune system?

To prevent food allergies in your dog and minimize their impact on the immune system, it is recommended to feed your dog a simple and healthy diet. This diet should have as little ingredients, additives, and preservatives as possible. By providing a clean and minimally processed diet, you can reduce the chances of food allergies developing and safeguard your dog’s immune system.

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2 thoughts on “Apoquel For Dogs – Side Effects Of Apoquel For Dogs”

  1. My dog Jessi who is twelve now has been on Aboquel for about three years. She has gone through tests because her symptoms are similar to Crushing disease. After reading this and putting out way too much money, she is getting off this pill.
    She has been so sick and I have been going through anxiety over all this. She has all the symptoms from a pill that should not be given to dogs. Thanks for the article.

  2. My 7 year old blue heeler was prescribed Apoquel for some sort of eye allergen she must’ve came into contact with that was causing her eyes to itch, I didn’t do my research about this medication and feel I should have! About 5 days after I started her on this medication she started having other troublesome symptoms such as hind lameness, couldn’t walk barely, her back legs were stiff & she would fall down easily while walking, I of course panicked thinking that her age related arthritis was suddenly getting much worse rapidly and I was a mess! Then came the severe diarrhea, which was odd to me because how would her arthritis worsening cause diarrhea?! So I decided to discontinue the medication and get her into the vet asap, well the only appt that was available wasn’t for a couple days and since she wasn’t crying or showing symptoms of being in pain aside from her legs not functioning properly I decided to wait it out until the appt, she hasn’t taken the Apoquel or the eye ointment the vet prescribed her in two days and last night she began walking much better, this morning the day of her scheduled appt, she is walking normally, jumping on and off the couch again & pretty much back to herself with a bit of lingering diarrhea that’s becoming more solid! I really believe this medication caused my girl to lose her ability to walk and caused the severe diarrhea! I am so upset that I allowed this to happen by not doing my research and just giving her the medication blindly! Folks please do your own research and ask the vet questions regarding anything they prescribe, including rare side effects! Don’t make the same mistake I did!


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