/* Google adsense */ /* GOOGLE ANALYTICS */

Apoquel tablets (generic: Oclacitinib maleate) are used to treat chronic allergic disorders in dogs, cats, and other small animals. It is a Food and Drug Administration (FDA) approved immunosuppressive drug that has very good feedback when is used for treating eczema (severe skin allergic disorder), psoriasis, and other allergies in dogs.

It works by blocking JAK-1 cytokines in the body (released by the immune system). Oclacitinib relieves swelling, itching, irritations, redness, on the skin, etc very fast.

It starts showing (good) effects within the first 4 to 6 hours of oral intake. So, it has become very popular and is the top choice of veterinarians for treating severe allergies.

But as an immune system suppressant, Oclacitinib (brand name: Apoquel) shows some negative side effects in dogs.


For Puppies

Apoquel is not recommended for puppies and dogs that are below one year old (< 12 months). Veterinarians discourage its use in small pets because the ratio of side effects is sky-high in young dogs, as well as in old ones (who have a compromised or weak immune system).

In the following piece of article, I decided to share all possible side effects of Oclacitinib maleate (an immunosuppressant drug) or Apoquel tablets in pets. By reading this article, you will become fully aware of the good and bad of this allergy medicine.

Negative Side Effects of Apoquel in Dogs

General adverse reactions by using immunosuppressants in dogs may include neurological or mental disorders, upset digestive system, urinary tract problems, certain skin diseases, cancer, allergies, swelling, pancreatitis, bacterial or viral infections, weight gain, and bleeding, etc.


Apoquel in dogs (in care cases) may cause certain brain disorders. Consult a veterinarian, if your pet is facing the following behavior issues

  • Anxiety
  • Drowsiness
  • aggression
  • Panting
  • behavior changes
  • drooling
  • seizures
  • barking so bad

Digestive Disorders

Apoquel rarely causes digestive tract disorders in dogs. However, if you see the following adverse reactions by using Oclacitinib maleate medication in dogs. Immediately discontinue the medicine and seek a veterinarian’s advice.

  • constipation
  • diarrhea
  • gas
  • vomiting
  • increased thirst
  • bad breath
  • loss of appetite (anorexia)


Apoquel increases the risks of cancers as it suppresses a body’s defense system which helps to fight against harmful pathogens, i.e. bacteria, viruses, fungi, and other microbes, etc.

It contains the active ingredient, “oclacitinib maleate” which belongs to immunosuppressants, i.e. cyclosporin. It works by influencing the job of a defense system, so a pet becomes more vulnerable to diseases such as infections.

It worsens the pre-existing condition, such as a bacterial infection, a viral infection, pancreatitis, hepatitis, etc. Some of the major defects of using oclacitinib in dogs are listed below (that could be fatal and life-threatening);

  • Lymphoma
  • Neoplasia
  • Tumor
  • Head tremor

Urinary Tract Disorders

Apoquel tablets may cause urinary tract infections in dogs. A urinary tract is consists of kidneys, bladder, ureters, urethra, penis (in males), uterus, and vagina (in females), etc.

Commensals bacteria and fungi remain present in a dog’s urinary tract without causing any harm to their bodies. They don’t develop an infection because their replication (growth or population) is controlled by the defense system of the body, i.e. immune system or called immunity.

An immune system suppressant drug may cause (not always but in some cases) over-population or over-growth of these microbes that result in a severe infection.

FDA-approved drugs (antibiotics) are used in the treatment of bacterial infections of the dog urinary tract (UTI).

Cefpodoxime proxetil, Enrofloxacin, Co-trimoxazole, Amoxicillin, Levofloxacin, Doxycycline, Sulfadimethoxine, Cefovecin, Cefalexin, etc are the examples of some broad-spectrum, highly effective, and powerful antibiotics (fights against the germs of bacteria).

Some general urinary tract side effects of Apoquel (Oclacitinib maleate) in dogs are listed below;

blood in urine
blood in the stool

Consult a veterinarian, if you observe any of these adverse reactions after using the medication.


As said above, all immune system suppressant drugs increase the risks of getting or developing a bacterial, viral, or fungal (yeast) infection very high. So, if this is the case you must observe your pet carefully. Because a bad breath after Apoquel medication could be a sign of dental infection in dogs.

Limit the treatment and try to consult a doctor first, if you see the following unwanted consequences;


Apoquel is available in three different potencies or strengths, i.e. 3.6mg, 5.4mg, and 16mg, respectively. Apoquel tablets are effective and in the majority of cases, they provide outstanding and reliable results.

But they do not always work if some cases a dog doesn’t feel better by using this treatment.

So if the pre-existing condition, i.e. dermatitis, atopic dermatitis, psoriasis, swelling (inflammation) on the skin, etc gets worsen. There is no need to continue this remedy.

Some veterinarians recommended Apoquel (0.4-0.6mg per one kilogram) twice a day (disclaimer: it’s not recommended by the FDA to take it twice a day, anyhow you must follow your veterinarian prescription).

Skin Disorders

These immune system suppressants’ side effects are very rare but surely possibles. Apoquel is used to treat skin disorders, i.e. redness, swelling, inflammation, itching, irritations, dryness, and discomfort of the skin neither for triggering it.

But for a few unfortunate pets, it may worsen the existing condition and may increase the severity. Apoquel side effects for skin in dogs are the following;

  • Bleeding
  • Dermal masses
  • Dry skin
  • hair loss

Apoquel Causes Weight Gain

A few pet owners reported that they see a visible increase in their pet’s physical weight after using this FDA-approved allergy medicine. Anyhow, it is not something that is inter-related.

In rare causes, apoquel (oclacitinib) may damage the liver, heart, kidneys, etc, and may indirectly cause weight gain or loss.

Using Apoquel for Long Term

Apoquel is (generally) recommended for long-term use for chronic diseases, i.e. eczema, psoriasis, etc. Some studies have been performed on this topic and they suggested that Oclacitinib is safe for long-term use and it doesn’t cause any side effects when used for more than 2 years (continuously).

The studies were performed with healthy dogs, those who were physical and mentally strong. Also, they were young and don’t have any liver, heart, or kidneys complications.

Anyhow, the long-term or persistent use of Oclacitinib medication in dogs is not completely understood and more studies should be performed to better understand its long-term effects in pets.

It weakens the immune system and increases the chances of developing infectious diseases, which also may increase the risks of cancers.

This costly treatment suppresses the symptoms of allergies, doesn’t treat allergy (on a permanent basis). So, your pet’s vet must diagnose the root cause of allergy in your pet to permanently relieve the symptoms.

Apoquel During Pregnancy

Apoquel medication is not recommended to use for pregnant, lactating, or nursing (female) dogs. The chances of side effects are sky-high in dogs that are undergoing pregnancy.

Apoquel Duration

The treatment is usually for the long term (for more than a year) unless the veterinarian succeeds in diagnosing the root cause of allergies in your pet.

Food, dust, pollen, dirt, smoke, smog, specific clothes, rubber, are some common allergens that trigger allergies in pets.
Figuring out the main cause of allergy and eliminating it from a pet’s life is the only solution to treat allergies in dogs. Consult a veterinarian for more details or contact us for more details.


The recommended or suggested dosage for Apoquel medicine is 0.4mg to 0.6mg per KG (kilograms) or 0.18mg to 0.27mg per Pound.

A veterinarian may suggest taking this medicine twice daily (or BD) but FDA doesn’t recommend taking Oclacitinib twice daily for more than two weeks or 14 days.

Taking Apoquel in high doses may cause serious adverse reactions in dogs, including certain digestive problems, infections, vomiting, diarrhea, lethargy, weakness, loss of appetite, etc.

In the case of Apoquel overdose, immediately visit a veterinarian. In severe cases, you can lose your furry friend for the rest of your life.

Stopping Apoquel Suddenly

Unlike steroids, oclacitinib could be stopped suddenly. But it is always suggested to stop or discontinue the use of Apoquel medication in dogs with the recommendation of a doctor or veterinarian.

Conclusion [Summarizing all in few Lines]

Apoquel is an immune system suppressant drug that is FDA-approved. This JAK (Janus Kinase)-1, 3 inhibitor works on certain cytokines (released by the immune system) that cause itchy skin. It is highly effective and rarely causes any side effects. It is not recommended in puppies and dogs below 12 months old or those who have a weak, compromised immune system.

Common Side effects of Oclacitinib (brand name: Apoquel) in dogs include some neurological disorders (anxiety, behavior changes, & enhance drooling), infections (caused by bacteria, fungi, or viruses), cancer (including neoplasia, lymphoma), and other.

In the case of side effects or adverse reactions, immediately discontinue the use and seek a piece of veterinarian advice. Apoquel may cause fatal and life-threatening reactions (in rare cases) that if left untreated may cost death.

Doctor Xeeshan

Doctor Xeeshan

I am Doctor Xeeshan, located in Lahore, Punjab, Pakistan. In this blog, I am providing authentic information about dog breeds, diseases, medications, etc.


Leave a Reply

Avatar placeholder

Your email address will not be published. Required fields are marked *

close X

Try The Best Rated Dog Food On Amazon

Ancient grains like grain sorghum, millet, quinoa and chia seed are naturally high in fiber and rich in protein. Unchanged for thousands of years, different grains provide various nutrients such as vitamins, minerals, antioxidants and omega fatty acids.