Questions about Zenrelia™?

Zenrelia is a newly licensed JAK inhibitor. It is approved for treatment of pruritus associated with allergic dermatitis in dogs, and for treatment of clinical manifestations of atopic dermatitis in dogs.

Zenrelia offers rapid and effective control of the most impactful symptoms of allergic and atopic dermatitis (pruritus and inflammation).¹

Owners expect to see their dog get back to normal with treatment.⁴ Almost 4 out of 5 patients achieve such good control that they are no itchier than a healthy dog.¹

Zenrelia has the added benefit of a simple once-daily treatment regime with or without food from the very start, and is priced so that more dogs can access the highly effective itch relief of JAK inhibitors for the long term.‡ Elanco offers a range of support tools for practices and pet owners who are ready to get started.

Yes, Zenrelia is suitable for long-term use. The SPC does not specify any limitations on treatment duration. Because canine atopic and allergic dermatitis are chronic conditions often requiring ongoing management, Zenrelia's safety has been rigorously assessed in studies evaluating its long term use.^1,3,6

It is recommended that dogs treated long-term are weighed regularly in case of significant weight changes that could affect their dosing requirements (NB we do not expect Zenrelia to induce weight changes, the concern is that if their weight changes for other reasons it might affect how much Zenrelia they need). Periodic monitoring of CBC (haematology) and biochemistry is recommended with long-term treatment. This is a recommendation not a requirement, and the SPC does not specify the frequency.

No. There are no special precautions for the protection of the environment on the Zenrelia SPC. Our regulatory system ensures that all veterinary medicinal products undergo an independent scientific assessment for quality, efficacy and safety – this includes safety to the environment. More information is available via NOAH.

It is still important to ensure owners know how to use and dispose of products correctly, and are encouraged to return any unused or unwanted tablets for proper disposal. Owners should be advised to avoid flushing tablets down the toilet, for example.

The most common observations, as with many medications, were vomiting and diarrhoea, but for Zenrelia these occurred at very low rates over the 4-month study: 8.3% for vomiting, 4.1% for diarrhoea, and 2.4% for lethargy.¹ Incidence of events does not necessarily imply causation. These low rates are reassuring and likely reflect what one might see in any dog population followed over 4 months. Pododermatitis and papilloma are also listed on the SPC, with ‘undetermined frequency’.

• Do not use in dogs with evidence of immune suppression.

• Do not use in dogs with evidence of progressive malignant neoplasia.

• Do not use in cases of hypersensitivity to the active substance or to any of the excipients.

There are no contraindications or special warnings for using Zenrelia with other medications. Zenrelia has been tested in real-world dogs who were receiving a wide variety of medications for other conditions. This included vaccines, antibiotics, parasiticides and NSAIDs^1,3. See below for the full list of concomitant therapies administered during the EU clincal field trial.¹ Use with other anti-pruritic medications such as glucocorticoids or cyclosporine has not been specifically evaluated. Zenrelia on its own has proven to be highly effective in the treatment of pruritus and clinical symptoms of atopic and allergic dermatitis. For further information, see Table S6 in the supporting information. 

While there is no specific contraindication to using Zenrelia with any other product, we encourage you to perform a risk-benefit assessment and decide on a case-by-case basis. Particular considerations are listed on the SPC in section 3.8.

Yes. It is appropriate to vaccinate dogs treated with Zenrelia. As with any other concomitant medication, a risk/benefit assessment should be performed by the responsible veterinary surgeon.

Zenrelia was used in conjunction with vaccinations during field trials with no interactions observed, and there is also a comprehensive study looking at its effect on booster vaccinations, which showed no difference in serological responses between control dogs and dogs being treated with Zenrelia, even at a 3x overdose.⁵ 

When treating pruritus associated with allergic dermatitis, investigate and treat any underlying causes (e.g. flea allergic dermatitis, contact dermatitis, food hypersensitivity). Furthermore, in cases of allergic dermatitis and atopic dermatitis, it is recommended to investigate and treat complicating factors, such as bacterial, fungal or parasitic infections/infestations (e.g. flea and mange).

Use of Zenrelia has not been evaluated in dogs with hepatic or renal disease. Use of Zenrelia in these sub-populations should be according to a risk/benefit assessment by the responsible veterinary surgeon.

Use of Zenrelia in dogs with anaemia has not been evaluated and should be according to a risk/benefit assessment by the responsible veterinary surgeon. 

Ilunocitinib, the active ingredient in Zenrelia, is excreted in faeces (~50%) and urine (~30%). The main component identified in urine and feces was unchanged ilunocitinib, and the liver metabolises a minority of it into metabolites.

There is no specific requirement to do so, however establishing baseline bloodwork prior to starting a dog on any long-term medication and then conducting regular blood checks tailored to the individual case could be considered best practice and may be done at the discretion of the veterinary surgeon.  

The SPC recommends that periodic blood testing be carried out in dogs that are to receive long-term treatment, and these results are likely to be more useful if a baseline picture was established first.  

Any blood changes associated with Zenrelia are usually not clinically relevant. At the start of treatment, decreases in leukocyte (monocyte, eosinophil and neutrophil) counts and a reduction in red cell mass parameters (red blood cell count, haemoglobin and haematocrit) may be seen. These changes typically remain within the laboratory reference range and stabilise within the first month of treatment. However, periodic monitoring of complete blood counts and serum biochemistry is recommended when dogs are on long-term treatment. 

Zenrelia can be used in all dog breeds, as long as they meet the age and weight requirements (12 months or older and 3kg or heavier). There are no breed-specific contraindications for Zenrelia. However, as with any medication, individual responses can vary. 

No. The safety of Zenrelia has not been established during pregnancy, lactation, or in breeding dogs. However, laboratory studies in rats have shown evidence of foetotoxic effects. Therefore, Zenrelia's use is not recommended during pregnancy, lactation or in dogs intended for breeding.