Apoquel Side Effects for Dogs (Surprising Risks Revealed)

apoquel side effects

If your dog has allergies or other skin conditions, your vet may recommend Apoquel. But before you consider this immune suppressing drug, it’s important to understand Apoquel side effects. Just how safe is it?

What Is Apoquel For Dogs?

Apoquel is an anti-allergy drug that’s often prescribed by vets. It’s touted as being “a fast-acting and safe treatment for the control of acute and chronic canine pruritus.” Pruritus means itching. When your dog is itchy, you get desperate to make him feel more comfortable. Nobody wants to be itchy and constantly scratching.

A dose of this medication can ease your dog’s allergic itch in as little as 4 to 24 hours. And dog owners do say the drug works to relieve their dogs’ itching. Sounds like something you might want to try, right?

Well, not so fast … Apoquel demolishes essential parts of your dog’s internal disease-fighting systems.

How Does Apoquel Work?

Apoquel affects the body’s kinases. Kinases are signaling compounds that cells use to communicate with each other. In the 1980s, an Australian chemist discovered some new ones, known as JAK1, JAK2, JAK3 and TKY2. With the growing epidemic of dog allergies, pharmaceutical companies saw an opportunity. They developed a drug that would stop these JAKs in their tracks.

And they sure succeeded. The kinase inhibitor Oclacitinib maleate, under the brand name Apoquel stops JAKs from doing their job. JAKs are key elements in controlling both growth and development. These particular JAKs do the work of:

  • Policing the body against tumor formation
  • Controlling body growth and development
  • Forming white and red blood cells
  • Ensuring antibody-producing B cells and “policing” T-cells are functioning well
  • Regulating inflammatory response

Apoquel has a unique mechanism that’s different from other allergy drugs … and that’s to interrupt JAK cell signaling compounds. Apoquel prevents JAKs from working. And without JAKs your dog’s immune system cannot function correctly.

  • JAK1 is vital for the constant surveillance within your dog’s body. Its job is to find and destroy abnormal cells that have become cancerous … before they form tumors. And it’s needed to destroy invading parasites, fungi, bacteria and viruses.
  • JAK2 is central to the production of bone marrow stem cells. These cells then become red and white blood cells and platelets.
  • JAK3 helps your dog’s antibody system (B cells) and its killer-cell system (T cells) work properly.

These JAKs all talk to each other and share information to keep your dog’s body healthy. So you can see that by preventing JAKs from working … Apoquel undermines your dog’s immune system to prevent allergic reactions.

Is Apoquel Safe For Dogs?

A safety study by Apoquel manufacturer Zoetis reported there were no fatalities and abnormal health events in a 28 day study. But abnormal health events were reported in 11 of 179 dogs post-study. These include:

  • 1 dog got euthanized after 450 days of the drug. The dog had developed abdominal ascites and pleural effusion of unknown etiology. This means that he had a fluid-filled abdomen and chest.
  • They euthanized another 6 dogs because of suspected malignant neoplasms. Those are cancers that spread easily … but aren’t detected because of immune suppression.
  • 2 dogs each developed a Grade II mast cell tumor  after 52 and 91 days.
  • 1 dog developed low-grade B-cell lymphoma after 392 days.
  • 2 dogs each developed an apocrine gland adenocarcinoma. One was dermal, the other an anal sac. These problems happened after only 210 and 320 days on Apoquel.
  • 1 dog developed a low-grade oral spindle cell sarcoma after 320 days. It’s a very painful oral cancer for dogs.

Drug research is easy to manipulate. When it comes to Apoquel side effects, Zoetis Inc claimed:

“There were no fatalities and no abnormal health events that necessitated hospitalization in either the study phase [day 0–7 (+3 days)] or the continuation phase [day 8–28 (±20 days)] of the study. Given that the majority of dogs in the placebo group withdrew after the completion of the study phase, the incidence of abnormal clinical signs was similar in both groups.”

It seems from these comments that the drug is fairly safe … but the duration of the study was only 7 days! There was a “continuation phase” after the 7 day study period, from 8 to 30 days. The researchers report:

“Six dogs (four oclacitinib and two placebo group) were withdrawn from the study during the continuation phase for abnormal health events. Abnormal health events were reported in 11 of 179 oclacitinib-treated dogs post-study. These were as follows: diarrhea (four dogs; severe enough to warrant cessation of treatment in one dog); vomiting (four dogs); fever, lethargy and cystitis (one dog); an inflamed footpad and vomiting (one dog); and diarrhea, vomiting and lethargy (one dog).” 

So about 6% of dogs tested had abnormal health events. Maybe that doesn’t seem very high to you, but keep in mind that was only for 30 days! How long can a dog take apoquel before they suffer side effects? The manufacturer says it’s safe for long-term use … but the study results say something different about the side effects of Apoquel in dogs.

The FDA doesn’t think Apoquel is safe, according to a warning letter they sent the manufacturer about “False Or Misleading Risk Presentation” in promotional materials. Read the FDA’s warning letter.

Apoquel Safety For Puppies

Apoquel is limited for use in dogs over 12 months old. They conducted a margin of safety study on 6 and 12 month old dogs. The study on 6 month old dogs ended quickly. They had developed bacterial pneumonia and demodectic mange infections!

Here’s the warning on the company’s website:

“IMPORTANT SAFETY INFORMATION: Do not use APOQUEL in dogs less than 12 months of age or those with serious infections. APOQUEL may increase the chances of developing serious infections, and may cause existing parasitic skin infestations or pre-existing cancers to get worse.”

In the 12-month old dogs here is a partial list of the Apoquel side effects seen in the study:

  • Papillomas (warts)
  • Interdigital furunculosis (cysts) with related dermatitis symptoms
  • Edema of feet
  • Pneumonia
  • Lymphadenopathy (abnormal or swollen lymph nodes) in peripheral nodes

Yes, you read right. The side effects include various types of skin diseases. But skin problems are what you’re trying to control by using Apoquel for most dogs. The drug was also found to lower white and red blood cell count. And it impacted certain types of lymphatic tissue … lymph nodes as well as bone marrow.

Is There An Alternative To Apoquel For Dogs?

Therapies like acupuncture and homeopathy can help dogs with environmental allergies. But acupuncture results tend to be short term and may need repeating every couple of weeks. Homeopathy works well but it can be a slow process. Your homeopath will usually need to prescribe a series of remedies until you find one that works for your dog.

Natural Alternatives Without Apoquel

Here are 5 natural alternatives to apoquel for dogs you can try, that won’t cause the most common side effects:

1. Topical Solutions

Use a topical product that works to calm the source of the itchy skin and skin inflammation. Your dog’s skin has 10 times more mast cells than humans do on their skin. So it’s no surprise they’re constantly scratching … but scratching increases the intensity of the itching, because it activates more mast cells. When your mother told you that the more you scratched that mosquito bite, the more it would itch … she was spot on!

So if you can nip the first itchy spot in the bud, you’re way ahead of the game. Itching begets scratching and if we can handle the first set of itches we may win the battle.

Here are some things you can use to help the itch.

  • Derma Drops by Spa Diggity Dog: Apply to itchy spots as soon as you can.
  • Zymox: This comes in a spray-on or cream formula. It’s excellent for itchy hotspots. You can find it on Amazon. Make sure you get the one without hydrocortisone which is a steroid. 
  • Baking Soda: You can make a poultice and slurry it on the area.
  • NuStock: A great dependable product to nip itching in the bud.

Remember … many dogs have seasonal allergies. You can give these products during the common allergy seasons, the spring and fall. Another important point is that it’s difficult to get dogs off of Apoquel, so you need something on hand.

Read about more topical solutions for itchy dogs …

2. Chinese Herbs

Zhu Dan Tablets from Seven Forests can help with the itch. I recommend giving these with a meal.


  • ½ pill to 1 pill twice a day for a smaller dog
  • 1 pill two to three times a day for a medium dog
  • 2 pills two or three times a day for a large dog

3. Histoplex by Biotics Research

Histoplex is a blend of herbal extracts shown to help regulate the immune systems. I find it works well for our dogs also.


  • A small dog can get ½ pill twice a day
  • Medium dog 1 pill twice a day
  • A large dog can have up to 3 pills twice a day while 2 pills twice a day usually suffices.

4. Betathyme

Betathyme is a naturally formed steroid that can help to stop that itch. Follow the directions on the label.

5. Atronex by Standard Process

This is a very niceproduct that helps to curb the itch. Like Betathyme, follow the directions on the label.

Apoquel looked like a miracle for dogs with allergies … and the owners watching them itch.  Unfortunately, it turned out to be anything but. The negative effects of this drug as well as other conventional drugs are now well known. And fortunately, the patent on Apoquel doesn’t expire until 2026, so it will be a while before anyone can flood the market with generic Apoquel for dogs.

Kicking The Apoquel Habit

Over my many years of experience with holistic modalities, that’s what I’ve found works best. It’s non-invasive, non-toxic … and helps create a stronger immune system. An immune system that can and will fight off cancer and disease.

Unlike Apoquel … which stops that intolerable itching at the high cost of:

  • A low white cell count
  • A low red cell count
  • Stunted growth 
  • Increasing your dog’s risk of cancer.

When I became a veterinarian I vowed to protect the health of our pets. I wanted to make them healthier and help them live longer and happier lives.

Sometimes, with all these new and confusing drugs that pet owners rush to, I feel like I’m swimming upstream.


Cosgrove S, Wren J, Cleaver D, Martin D, Walsh K, Harfst J, Follis S, King V, Boucher J, Stegemann M. Efficacy and safety of oclacitinib for the control of pruritus and associated skin lesions in dogs with canine allergic dermatitisNational Center Of Biotechnology Information. 5, July 2013.

Cosgrove S, Cleaver D, King V, Gilmer A, Daniels A, Wren J, Stegemann M. Long-term compassionate use of oclacitinib in dogs with atopic and allergic skin disease: safety, efficacy and quality of lifeNational Center Of Biotechnology Information. 26, June 2015.

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