Key Highlights
- Zenrelia (ilunocitinib tablets) is a new, once-daily medication for dogs 12 months or older that helps manage itching due to allergic and atopic dermatitis.
- Apoquel and Zenrelia act as a JAK inhibitor, targeting the immune system.
- It's important to understand the implications of warnings regarding the use of drugs that impact the immune system.
- Potential side effects are similar to Apoquel, including vomiting, diarrhea, and lethargy.
- Zenrelia's safety in pregnant, lactating, or breeding dogs has not been evaluated.
Introduction
As an integrative and holistic veterinarian, my primary goal is to ensure the health and well-being of your pet by exploring all possible avenues for treatment—whether they are traditional medicines or holistic alternatives. Allergic dermatitis is a distressing condition that can severely impact a dog’s quality of life, leading to intense itching, inflammation, and discomfort. Recently, a new drug called Zenrelia has been approved for this purpose, and it’s essential to critically evaluate its potential benefits and risks.
Understanding Zenrelia and Its Role in Treating Allergic Dermatitis in Dogs
Zenrelia, also called ilunocitinib tablets, is prescribed to treat dogs suffering from the itching of allergic dermatitis, including atopic dermatitis. This new medicine works by blocking Janus kinases, which are important enzymes involved in inflammation.
By stopping these enzymes, Zenrelia can break the chain of events that cause itching. This medication is in the same type of drug as Apoquel, or oclacitinib. It can be given once a day, where Apoquel is started at twice a day, with some dogs only needing once a day dosing.
The Science Behind Zenrelia: How It Works as a JAK Inhibitor
A Janus Kinase (JAK) inhibitor is a type of medication that helps to reduce inflammation in the body. It works by blocking specific enzymes called Janus kinases, which play a role in the signaling pathways that lead to inflammation and immune responses.
While this mechanism can provide much-needed relief for dogs suffering from allergic dermatitis, it’s important to recognize that by dampening these signals, we may also be suppressing the immune system's ability to respond to other challenges, including infections and vaccinations.
Potential Downsides of JAK Inhibitors
The immunosuppressive nature of current JAK inhibitors raises significant concerns. While they may provide immediate relief from allergic reactions, they can also leave a dog vulnerable to infections and may hinder the body’s response to vaccines. This is crucial for both young and older dogs. For instance, while younger dogs typically have a lower risk of developing cancer, older dogs—especially those already battling cancer—might find their situation exacerbated by a drug that suppresses their immune response.
What does this mean for the immune system, and why did the FDA warn veterinarians?
While this mechanism can provide much-needed relief for dogs suffering from allergic dermatitis, it’s essential to recognize that by dampening these signals, we may also be suppressing the immune system's ability to respond to other challenges, including infections and vaccinations. The studies to demonstrate efficacy were done in 10-month-old Beagle dogs. The FDA issued a letter (1) to veterinarians stating "Before using Zenrelia, read the entire package insert, including the boxed warning describing the risk of vaccine-induced disease and inadequate immune response to vaccines." They also warned that "Zenrelia-induced immunosuppression may increase the risk of opportunistic infections, including demodicosis, interdigital furunculosis, coccidiosis, and pneumonia, and may also exacerbate subclinical or uncomplicated infections. New neoplastic conditions (benign and malignant) were observed in dogs treated with Zenrelia during clinical studies. You should consider the risks and benefits of treatment before starting Zenrelia in a dog with a history of recurrent serious infections or recurrent demodicosis or neoplasia. You should also monitor the dog for the development of infections while on the drug."
Limitations of the laboratory studies done thus far
The safety study and efficacy of Zenrelia were evaluated in a study involving 10-month-old Beagles over six months. While the results seem promising, it is crucial to note that the young age of the dogs in the study means we don’t yet fully understand how Zenrelia will affect older dogs, especially those with pre-existing health conditions.
How does Zenrelia compare to Apoquel?
Black Box Warnings:
- Zenrelia: The FDA has issued warnings regarding potential immunosuppression, particularly affecting the response to vaccinations.
- Apoquel: Dogs with existing infections do not have the same level of concern regarding vaccination response, but caution is still advised.
Side Effects:
- Zenrelia: Some potential side effects include vomiting, diarrhea, and decreased appetite, similar to Apoquel, but with additional considerations regarding immune response.
- Apoquel: Also has side effects that include vomiting and diarrhea, but has a well-established profile over years of use.
Frequency of Dosing:
- Zenrelia: Administered once daily.
- Apoquel: Typically requires dosing twice daily initially, which can decrease to once daily after a few days.
A Holistic Approach to Allergic Dermatitis
In my practice, I advocate for exhausting all possible alternatives before resorting to immunosuppressive drugs like Zenrelia or Apoquel. Consider implementing a minimally processed diet or a food trial to help rule out food intolerances or allergies and to lower the playing field for inflammation in the body by feeding a minimally processed diet.
Seeking the advice of a holistic or integrative veterinarian to explore how nutrition, supplements, herbal remedies, and lifestyle changes might improve your dog's quality of life and treatment success without the inherent risks of immunosuppression. Discuss allergy testing and desensitization as some general practitioners do this type of testing.
Conclusion
Given the potential risks associated with Zenrelia and JAK inhibitors, it may be prudent to explore alternative approaches before jumping into new medications. One such approach is transitioning your dog to a minimally processed diet or implementing a food trial to help reduce inflammation in the body. Natural remedies and nutrition can significantly manage allergic reactions without the side effects associated with pharmaceuticals.
As we continue learning more about Zenrelia and its long-term effects, I encourage you to consult your veterinarian to determine the best course of action for your dog. While we naturally want to help our dogs feel better by being less itchy, we want to make sure we do not cause another problem to manifest. Together, we can navigate the complexities of canine health and discover the most suitable options for your furry family member.
Frequently Asked Questions
Are there holistic approaches I can consider alongside Zenrelia?
Yes! Explore minimally processed diets, food trials, and holistic supplements that can help reduce inflammation and improve your dog’s overall health, potentially enhancing the effectiveness of any medication. Consulting with a holistic veterinarian can provide tailored advice.
Can Zenrelia be used in older dogs with pre-existing conditions?
While Zenrelia can be used in older dogs, caution is advised, especially if the dog is battling chronic conditions like cancer due to the drug's immunosuppressive effects. Many cancers never take hold because our immune system tags them as abnormal and they are eliminated. My concern would be that we blunt this response in older dogs.
Should I see a veterinary dermatologist?
Yes, seeing a veterinary dermatologist for allergy testing can be valuable in managing your dog's allergic dermatitis. Veterinary dermatologists specialize in skin conditions and can offer comprehensive evaluations, especially if your dog's condition is chronic, you feel like you are spinning your wheels, and your pet's quality of life is compromised. Veterinary dermatologists have advanced training and experience in diagnosing and treating skin issues, including allergies. They can provide a more detailed assessment of your dog’s condition. Allergy testing, which may include intradermal testing or serum tests, can help identify specific allergens triggering your dog's symptoms. This targeted approach allows for more effective management strategies.
What Should Pet Owners Know About the Immunization Schedule When Using Zenrelia?
Zenrelia can change how a dog's immune system reacts to vaccines. It is essential to talk about when to give vaccines with your vet. Your vet might suggest pausing Zenrelia for some time before and after the vaccination. This way, your dog can have an adequate immune response.
Reference:
(1) https://www.fda.gov/animal-veterinary/product-safety-information/dear-veterinarian-letter-regarding-important-safety-information-associated-use-zenrelia-ilunocitinib
