What is Apoquel and how does it work in dogs?

What is an apoquel?

Apoquel is a modern, targeted veterinary medication used to control itching and inflammation in dogs, particularly those related to allergies . It is most commonly used to manage severe itching associated with atopic dermatitis and allergic skin diseases . A key feature of Apoquel is that, unlike corticosteroids used in classic allergy treatments, it directly targets the signals that cause itching, rather than broadly suppressing the immune system.

Allergic diseases in dogs result from an excessive immune response to external factors such as environmental allergens, house dust mites, pollens, mold, foods, or fleas. During this process, certain chemical messengers released by skin cells and immune cells trigger the sensation of itching. Apoquel intervenes precisely at this stage, suppressing the transmission of the itching signal and significantly improving the dog's quality of life.

The main reasons why Apoquel stands out in clinical use are as follows:

• It can reduce itching very quickly.

• It has a more controlled effect profile compared to steroids when used long-term.

• It quickly relieves intense itching, redness, and skin irritation that can make daily life difficult.

Because of these properties, Apoquel has become a widely preferred treatment option for symptom control in both acute itching attacks and chronic allergic diseases.

Apoquel's Active Ingredient and Mechanism of Action

The active ingredient in Apoquel is called oclacitinib. Oclacitinib is a specific molecule that targets certain intracellular signaling pathways in the immune system. It acts by inhibiting a group of enzymes called Janus Kinase (JAK) . This mechanism is the key difference between Apoquel and classic allergy medications.

When allergic itching develops in dogs, various cytokines, primarily interleukin-31 (IL-31), are released by immune cells. IL-31 is a key molecule that stimulates nerve endings, causing the sensation of "itching" in the brain. For this cytokine to exert its effect, it needs the JAK signaling pathway. Oclacitinib, the active ingredient in Apoquel, blocks this signaling pathway by inhibiting the relevant JAK enzymes, primarily JAK-1.

As a result of this blockage:

• The itching signal cannot be transmitted to the nervous system.

• Skin inflammation decreases.

• Redness, irritation, and self-harming behavior subside quickly.

The most remarkable aspect of Apoquel's mechanism of action is that it suppresses cytokines associated with itching and allergies without disabling the entire immune system. This means the dog's overall immune response is not completely halted; only the pathways contributing to the allergic process are targeted.

Thanks to this selective action, Apoquel provides a significant reduction in itching within the first few hours in many cases. Clinical observations show that relief begins on the first day of treatment in most dogs, and itching is controlled within a few days.

Apoquel Usage Instructions and Basic Dosage Principles

Correct dosage and regular use are crucial for the effective and safe administration of Apoquel. The dosage is determined by the dog's body weight and is usually administered orally in tablet form. Tablets can be given whole or divided if necessary.

In clinical practice, Apoquel is generally administered using a two-stage dosing approach. The first stage is the initial phase , aimed at rapid control of itching. During this phase, the medication is given at more frequent intervals. Once itching is controlled, the maintenance phase begins, and the frequency of doses is reduced.

The aim of this approach is:

• To suppress itching as quickly as possible.

• Maintaining symptom control with the lowest effective dose in the long term.

Whether Apoquel is given with food or on an empty stomach generally does not significantly affect its effectiveness. However, in dogs with sensitive stomachs, giving the medication with food may improve tolerability.

The key points to consider during the treatment process are as follows:

• The medication should be given at the same time every day.

• If a dose is missed, a double dose should not be administered.

• Treatment should not be stopped abruptly; if necessary, it should be regulated in a controlled manner.

Because Apoquel is a symptom-suppressing medication, dosage adjustments should always be made based on the clinical picture and the dog's response . Therefore, regular veterinary check-ups are important in cases where long-term use is planned.

In what situations is Apoquel used in dogs?

Apoquel is a medication primarily used to control itching caused by allergies . The key point is that Apoquel doesn't eliminate the root cause of the condition , but it significantly improves the dog's quality of life by suppressing the itching , which is the most bothersome symptom of the allergic process. Therefore, it is generally considered part of a symptom-control treatment approach.

The clinical situations in which Apoquel is most commonly used are:

• In atopic dermatitis, a chronic skin disease caused by environmental allergens (such as pollen, house dust mites, and mold spores), Apoquel is preferred for quickly and effectively controlling itching. In dogs with atopic dermatitis, itching often persists year-round, and Apoquel is used for long-term symptom management in these cases.

• In allergic dermatitis, an allergic skin condition characterized by redness, itching, hair loss, and irritation, Apoquel is used to suppress inflammation and itching.

• Flea allergy dermatitis (FAD): In dogs with hypersensitivity to flea bites, even a single bite can cause intense itching. Apoquel, when used in conjunction with antiparasitic treatment, helps to quickly reduce itching.

• In cases suspected of food allergies, Apoquel may be used for temporary symptom control during an elimination diet if the dog experiences significant discomfort due to itching. The main goal in this use is to maintain the dog's comfort until the diet process is complete.

• For cases of chronic itching with an unclear cause , Apoquel can be used as short- or medium-term support to prevent the dog from constantly scratching and harming itself while the diagnostic process continues.

Apoquel is preferred in these situations because its effect starts quickly and in many cases provides a significant reduction in itching within a few hours. This provides significant relief, especially for dogs experiencing intense itching.

How does the itching and allergy mechanism work in dogs?

In dogs, itching is not simply a skin problem; it is the result of a complex immune-nervous system interaction . In an allergic dog, the immune system perceives normally harmless environmental substances as a threat and creates an exaggerated defensive response to them.

This process generally works as follows:

First, the allergen (such as pollen or house dust mites) passes through the dog's skin barrier. In dogs prone to allergies, the skin barrier is often weakened, making it easier for allergens to pass through. When these substances encounter immune cells, the immune system is activated, and various inflammatory cytokines are released.

Among these cytokines, interleukin-31 (IL-31) plays a key role in the development of itching. IL-31 stimulates nerve endings in the skin, triggering the sensation of itching, and this signal is transmitted to the brain via the spinal cord. As a result, the dog experiences intense itching and exhibits constant scratching behavior.

As the itching continues:

• Skin integrity is compromised.

• Secondary bacterial and fungal infections may develop.

• Inflammation increases further.

• The itch-inflammation cycle deepens.

Unless this cycle is broken, the clinical picture in the dog will progressively worsen. This is where Apoquel comes in, targeting the molecular step where the itching signal is generated. Its ability to intervene at such an early stage of the itching mechanism is the main reason why the drug delivers rapid and effective results.

How does Apoquel relieve itching so quickly?

The main reason Apoquel is so frequently preferred in clinics is its ability to suppress itching very quickly . In many dogs, a significant reduction in scratching behavior is observed within the first few hours after administration of the medication. This rapid effect is due to the biological pathway targeted by Apoquel.

In dogs, the sensation of itching doesn't begin on the skin's surface; it's primarily a signal transmitted through the nervous system . Cytokines like IL-31, released during allergic reactions, stimulate nerve endings in the skin, and this stimulation is transmitted to the central nervous system. Oclacitinib, the active ingredient in Apoquel, inhibits the JAK signaling pathway, which is necessary for these cytokines to exert their effects, thus interrupting the itching signal before it's even transmitted.

Therefore, Apoquel:

• It indirectly suppresses histamine release.

• It prevents overstimulation of nerve endings.

• It prevents the itching reflex from reaching the brain.

An important point is this: Apoquel's effect doesn't just provide superficial relief. As the itching decreases, the dog's self-scratching and biting behavior also decreases , allowing the skin to heal. Thus, a reduction in redness, scaling, and traumatic skin lesions is seen in a short time.

This rapid effect offers a significant advantage in terms of immediate symptom control , especially in dogs that scratch incessantly throughout the night, cannot sleep, or have irritated skin to the point of bleeding. However, it is important to remember that Apoquel suppresses the itching; it does not eliminate the source of the allergy. Therefore, it is generally used while investigating the underlying cause or developing a long-term treatment plan.

Effects of Apoquel on the Immune System

One of the most frequently asked questions regarding Apoquel is about its effects on the immune system . This is because Apoquel targets an immune-related signaling pathway, which naturally raises the question of whether it "suppresses immunity?".

Apoquel does not work like classic immunosuppressive drugs that completely suppress the immune system. Oclacitinib specifically targets JAK-1-dominant signaling pathways . These pathways play a key role in the transmission of cytokines associated with itching and allergic inflammation. However, most of the immune system's primary defense responses against infections are mediated through different signaling pathways.

Thanks to this selective effect:

• Itching and allergic inflammation are suppressed.

• However, the dog's overall immune capacity is not completely disabled.

Nevertheless, Apoquel is considered to have a mild and controlled suppressive effect on the immune system. However, particularly with long-term use, some dogs may become more susceptible to bacterial or fungal skin infections. This is not so much due to the drug being directly harmful, but rather because the suppression of allergic reactions allows infections to progress more easily and go unnoticed.

Therefore, during Apoquel treatment:

• Regular check-ups for skin and ear infections.

• Dogs with a history of chronic infections are monitored more closely.

• Clinical examinations should not be neglected during long-term use.

This is important. When used with proper patient selection and appropriate monitoring, Apoquel has a controlled and predictable effect profile on the immune system.

What is the difference between Apoquel and steroids?

One of the main reasons for Apoquel's rapid acceptance in clinical practice is its different effect profile compared to corticosteroids . For many years, steroids have been the most commonly used drugs for controlling allergic itching in dogs. However, steroids are known for their powerful effects as well as the serious long-term side effects they can cause.

Steroids suppress the immune system extensively . This suppression affects not only allergic reactions but also the body's normal defense mechanisms. Long-term steroid use can lead to problems such as weight gain, muscle loss, liver strain, increased risk of diabetes, skin thinning, and increased susceptibility to infections.

Apoquel offers a different approach. The active ingredient in the drug targets specific signaling pathways associated with allergies and itching , rather than the entire immune system. Therefore:

• It does not create broad-spectrum immunosuppression.

• Metabolic side effects are significantly less compared to steroids.

• With long-term use, the risk of systemic side effects is more controlled.

Another important difference is the onset of effect . While steroids are effective, in some cases it may take several days to reach full effect. Apoquel, on the other hand, begins suppressing itching in most dogs within hours of the first dose.

However, Apoquel should not be considered a complete replacement for steroids. In some cases of acute, severe inflammation, steroids may still be necessary. The preferred approach in clinical practice is to use Apoquel in place of steroids or to reduce steroid dosage in appropriate cases. This provides both symptom control and reduces the risk of long-term side effects.

Important Safety Points to Consider When Using Apoquel

Although Apoquel is generally a well-tolerated medication, it is not a product that can be used without question in every dog and under every condition . Because the drug's mechanism of action is related to the immune system, certain safety precautions must be carefully considered during its use.

First, Apoquel should be carefully evaluated in dogs with active infections . If there are ongoing bacterial or fungal infections in the skin, ears, or other parts of the body, suppressing itching alone without treating these infections may mask the clinical picture. Therefore, it is important to control existing infections before starting Apoquel.

The following situations require special attention when using Apoquel:

• History of recurrent skin and ear infections.

• Chronic diseases related to the immune system

• Dogs with a history of tumors

• Patients who have been using other immune system-affecting drugs for a long time

Possible side effects that may be observed during Apoquel use include changes in appetite, mild gastrointestinal discomfort, and rarely vomiting or diarrhea. In most cases, these effects are mild and may appear in the first few days of treatment and resolve spontaneously.

Another important safety point concerns its use in young dogs . Because their immune systems are still developing and not fully mature, using Apoquel at a very young age is generally not recommended. Therefore, age and overall health should always be considered together.

During treatment, the dog's general condition, skin structure, and signs of infection should be regularly monitored; the treatment plan should be reviewed if any unusual conditions are noticed.

Is Apoquel suitable for long-term use?

One of the most frequently asked questions about Apoquel is whether long-term use of the medication is safe . This question is especially important for chronically allergic dogs that experience itching year-round.

Apoquel is considered a suitable option for long-term use when the right patients are selected and regular follow-up is provided. Its more targeted effect compared to steroids is one of the main reasons for its long-term preference. However, this does not mean uncontrolled and unlimited use.

The goal of long-term Apoquel use is as follows:

• Finding the lowest effective dose to keep itching under control.

• Avoiding unnecessary high doses or frequent use.

• Early detection of potential risks through regular clinical checkups.

In some dogs, symptoms can be controlled by initially using Apoquel regularly, gradually reducing the dosage or switching to an intermittent use pattern. This approach reduces drug exposure and improves long-term safety.

However, since Apoquel does not eliminate the underlying cause of the allergy, it should not be considered a permanent solution on its own . In dogs where long-term use is planned, the healthiest approach is to evaluate it in conjunction with environmental control, proper nutrition, skin barrier support practices, and other treatment options if necessary.

When used at the correct dosage and monitored with regular veterinary checkups, Apoquel can help maintain a good quality of life for many years in many dogs.

Which dogs should not have Apoquel?

Although Apoquel is a medication that can be safely used in many dogs, it should not be preferred or should be evaluated very carefully in some cases . The main reason for this is that the drug affects immune-related signaling pathways.

The following are situations where Apoquel should not be used or should be seriously questioned :

• In dogs with active infections, simply suppressing itching while there is an ongoing bacterial, fungal, or parasitic infection can lead to infection progression and mask the clinical picture. Therefore, treating the infection should always be the priority.

• Immunocompromised dogs: In dogs with congenital immune problems or those receiving immunosuppressive treatment for other reasons, the use of Apoquel should be carefully evaluated in terms of risk-benefit.

• In young dogs, the use of Apoquel is generally not recommended for puppies whose immune systems are not yet fully developed. Interfering with immune signals during development can lead to undesirable consequences later in life.

• Dogs with a history of tumors: Caution should be exercised when using Apoquel in dogs with a history of neoplastic disease, either past or present. In such cases, alternative treatment options should be considered first.

• In dogs with severe systemic disease, or those with serious liver , kidney , or endocrine system problems, the use of Apoquel should only be planned after a comprehensive evaluation.

Apoquel is not entirely forbidden in dogs belonging to these groups; however, it should not be a routine or automatic choice . Each case should be considered individually, taking into account the clinical picture, comorbidities, and alternative treatment options.

Follow-up and Monitoring Process During Apoquel Treatment

Regular follow-up and clinical evaluation are crucial for the safety and effectiveness of Apoquel treatment. The rapid symptom control provided by the medication can sometimes lead to overlooking underlying problems. Therefore, treatment should not be reduced to simply asking "has the itching gone?".

The key points to consider during the follow-up process are as follows:

During the first days of treatment, the level of itching, skin redness, and the dog's overall behavior should be closely monitored. As itching decreases, hidden infection foci in the skin may become more apparent. This may indicate the need for additional treatment.

For dogs where long-term use is planned:

• Regular examination of the skin and ears.

• Early detection of signs of recurrent infection

• Periodic clinical examinations as needed.

This is important. In some cases, the Apoquel dose may be reduced or the interval between uses extended depending on the clinical course. This approach both prevents unnecessary use of the drug and increases long-term safety.

Another important aspect of the follow-up process is continuing to investigate the underlying cause of the allergy . While apoquel suppresses symptoms, environmental control measures, appropriate dietary adjustments, and skin barrier support care practices should be continued simultaneously.

Apoquel treatments, when followed regularly and managed with a holistic approach, make itching control in dogs more sustainable in the long term.

Post-Apoquel Clinical Expectations and Treatment Success

Clinical expectations after initiating Apoquel treatment are generally based on rapid relief in the short term and controlled symptom management in the medium to long term. Most dogs experience a significant reduction in itching behavior after the first doses of the medication. This improves the dog's quality of life and gives the skin time to repair itself.

Successful Apoquel treatment typically involves the following developments:

• A decrease in persistent scratching, licking, and biting behaviors.

• Redness and irritation on the skin subside over time.

• Secondary infections can be controlled more easily.

• Sleep patterns and overall behavior are approaching normal.

However, clinical success should not be judged solely by the reduction of itching. Since Apoquel suppresses the symptoms of the allergic process, managing the underlying cause is the key factor determining the long-term success of the treatment. Apoquel's effectiveness becomes much more sustainable when used in conjunction with reduced exposure to environmental allergens, a proper diet, skin barrier support practices, and additional treatments if necessary.

While Apoquel alone may be sufficient for some dogs, other cases may require dose adjustments or intermittent use. The key to treatment success is using the medication correctly and for the required duration . In cases where regular follow-up, clinical response observation, and a holistic approach are used, Apoquel emerges as a reliable option for pruritus control.

Frequently Asked Questions

What exactly does Apoquel do in dogs?

Apoquel is a medication used to quickly control itching in dogs, particularly that caused by allergies . Its primary effect is to suppress the biological signals that trigger itching. This reduces persistent scratching, licking, and biting behaviors in dogs. Apoquel does not eliminate the root cause of the allergy; however, by controlling itching, the most bothersome symptom of the allergic process, it significantly improves the dog's quality of life.

How many hours does it take for Apoquel to start working?

One of Apoquel's most remarkable features is its rapid response . In most dogs, a significant reduction in itching behavior is observed within the first few hours of administration. In some cases, this effect is noticeable the same day, while in others it becomes clearer within 24 hours. This rapid effect stems from Apoquel targeting an early step in the itching mechanism.

Is Apoquel cortisone or steroid?

No, Apoquel is not cortisone or steroids . While steroids suppress the immune system broadly, Apoquel has a more targeted mechanism of action . Apoquel suppresses specific signaling pathways associated with itching and allergic inflammation. This difference is the main reason why it offers a more controlled side effect profile compared to steroids with long-term use.

Is Apoquel suitable for long-term use?

Apoquel is considered a suitable medication for long-term use with appropriate patient selection and regular follow-up. It is particularly preferable for long-term symptom control in dogs experiencing year-round allergic itching. However, the goal of long-term use is always to control itching with the lowest effective dose . Regular clinical check-ups enhance the safety of long-term use.

Does Apoquel suppress the immune system?

Apoquel does not produce a completely suppressive effect on the immune system; however, it provides controlled and selective suppression . It targets certain immune signals associated with itching and allergies. Therefore, the overall immune system is not completely deactivated. Nevertheless, it is important to be cautious and have regular follow-ups, especially with long-term use, due to increased susceptibility to infections.

Can Apoquel be used in puppies?

Apoquel is generally not recommended for use in very young dogs. Because puppies' immune systems are not yet fully developed, interfering with immune-related signaling pathways can lead to undesirable consequences. Therefore, the use of Apoquel should be planned considering age, overall health, and clinical picture.

Can infections be masked while using Apoquel?

Yes, because Apoquel suppresses itching , it can mask the symptoms of existing infections . Skin and ear infections, in particular, can be harder to notice when the itching is reduced. Therefore, it is important to treat active infections before starting Apoquel and to have regular check-ups throughout the treatment period.

Can Apoquel be abandoned abruptly?

Apoquel is not a medication that causes serious rebound effects when stopped abruptly like steroids. However, itching symptoms may return if the medication is stopped suddenly. Therefore, dose reductions or changes in frequency of use should be done in a controlled manner according to the dog's clinical condition. The aim is to prevent the recurrence of symptoms.

Is Apoquel used for every case of itching?

No, Apoquel is not suitable for every case of itching. In cases such as parasitic infections, fungal or bacterial skin diseases, the priority should be treating the underlying cause . Apoquel is more often preferred for itching of allergic origin. Simply suppressing symptoms without clarifying the cause of the itching can complicate the clinical process.

Is Apoquel a sufficient treatment on its own?

Apoquel effectively controls itching in most cases; however, it is not a permanent solution on its own . Best results are obtained when used in conjunction with environmental control measures, proper nutrition, skin barrier support practices, and additional treatments as needed. Apoquel should be considered an important part of a holistic allergy management plan.

Sources

• Zoetis Veterinary Product Information

• European Medicines Agency (EMA) – Oclacitinib Monographs

• American College of Veterinary Dermatology (ACVD)

• theveterinarymedicine.com

• vetscriptions.co.uk