There is no Apoquel class action lawsuit alleging the allergy drug harmed dogs or cats. As of mid-2026, no court has certified, and no plaintiff has filed, a product liability class action against Zoetis over injuries to pets from Apoquel (oclacitinib). The only active class action tied to the drug is a securities fraud case brought by investors, not pet owners. That said, a sharp rise in accidental overdoses from the newer chewable formulation, together with a recent ruling in a related Zoetis case, shapes what legal options do and don’t exist right now.
The Only Apoquel Class Action Is a Securities Case
On May 27, 2026, the law firm Labaton Keller Sucharow filed City of Ann Arbor Retiree Health Care Benefit Plan & Trust v. Zoetis, Inc., No. 26-cv-04401, in the U.S. District Court for the Southern District of New York. It is a securities fraud suit under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934. The plaintiffs are Zoetis shareholders, not pet owners, and the alleged harm is financial loss on the stock, not injury to any animal.
The complaint covers a class period from January 14, 2025, through May 6, 2026. It alleges Zoetis and certain executives misrepresented how well Apoquel and its injectable counterpart Cytopoint were performing against a newly launched competing canine dermatology treatment. According to the complaint, both products were losing substantial market share while the company continued to describe strong veterinarian adoption and growth. The suit also targets statements about Librela, a canine arthritis injection, and Simparica Trio, a parasiticide.
Zoetis reported first-quarter 2026 results on May 7, 2026, showing an 11% organic decline in its dermatology franchise, with revenue falling to $347 million from $377 million a year earlier. The company acknowledged “intensified competition in key pet care categories” and “market-share losses in dermatology,” and lowered full-year guidance. Zoetis stock fell more than 21% after the report. The deadline for investors to move for lead plaintiff was July 27, 2026. No class has been certified.
If you are a pet owner and your dog or cat was harmed after taking Apoquel, this case does not cover you. It does not allege the drug injured any animal.
Why Pet Owners Are Searching for This
The reason interest in an Apoquel class action has grown has less to do with the securities suit and more to do with a safety pattern in the chewable version of the drug. Zoetis brought the chewable formulation to market on July 31, 2023, flavored with pork liver and brewer’s yeast. Pets, especially cats, began finding and eating the tablets on their own.
According to the ASPCA Animal Poison Control Center, from June 2023 through mid-March 2025, there were 3,029 reported dog overdoses and 307 cat overdoses involving Apoquel, resulting in 36 deaths. In the nearly ten years before the chewable launched (December 2013 through May 2023), the same center logged 2,016 dog overdoses and 212 cat overdoses with zero deaths. The Pet Poison Helpline reported a nearly threefold increase in Apoquel overdose calls in the year after the chewable’s October 2023 debut. The FDA received 195 reports of accidental overdoses in dogs and 70 in cats between June 2023 and September 2025, and acknowledged those figures likely underrepresent the true scope.
Cats are more sensitive to oclacitinib than dogs. At doses of 10 to 15 mg/kg, cats can develop gastrointestinal distress, cardiovascular problems including abnormal heart rhythms and new murmurs, and central nervous system depression. Between 12 and 38 mg/kg, acute kidney injury can develop within 12 to 36 hours and progress to death within one to four days. The ASPCA has documented fatal kidney injury at doses as low as 6 to 15 mg/kg. In August 2025, NC State’s College of Veterinary Medicine issued a public alert after treating cats that developed acute kidney injury from the chewable tablets; both patients required multiple rounds of hemodialysis to survive.
Zoetis describes the overdose reports as “very rare,” defined as fewer than one incident per 10,000 dogs treated in a 30-day period. The chewable label, most recently updated on October 16, 2025, tells owners to “keep APOQUEL CHEWABLE in a secure location out of reach of dogs, cats, and other animals,” and specifically warns that “cats can get to areas, such as countertops, that may be safe from dogs.” As of mid-2026, the FDA has not issued a recall, a mandatory label change, a safety alert, or a “Dear Veterinarian” letter about the chewable overdose issue.
Why No Pet-Injury Class Action Has Been Filed
The absence of a class action is not just a matter of timing. A closely analogous case involving another Zoetis product shows why one would be hard to bring.
In October 2024, eight pet owners filed a class action against Zoetis over Librela, alleging the company concealed neurological risks. In October 2025, a federal judge in New Jersey dismissed most of the claims in Hartney v. Zoetis, No. 2:24-cv-09698. The ruling flagged several hurdles that would apply to any Apoquel class action:
- The learned intermediary doctrine. Because veterinary drugs are prescribed by a veterinarian, courts may require plaintiffs to show the vet relied on specific misleading materials from the manufacturer, not just that the drug carried risks the owner didn’t know about.
- A presumption that FDA-approved warnings are adequate. Under the New Jersey Products Liability Act, overcoming that presumption requires alleging the manufacturer deliberately concealed or failed to disclose post-approval risk information.
- Federal preemption concerns for design defect claims, since federal law limits a manufacturer’s ability to unilaterally change a drug’s formulation after FDA approval.
- Specificity requirements. The Librela consumer protection claims were dismissed because plaintiffs made only generic assertions about safety representations without identifying specific misrepresentations they personally relied on.
The Librela plaintiffs were granted leave to file a fourth amended complaint. For Apoquel, plaintiffs would face an added obstacle: the label already warns about accidental ingestion and instructs owners to keep the medication away from cats and other animals. That warning weakens a failure-to-warn theory built around the chewable overdose pattern.
What an Individual Pet Owner Can Do
If your animal was harmed, class action status is not the only route. A few options exist outside it:
- A product liability claim against Zoetis, if the harm resulted from a defective product.
- A veterinary malpractice claim against your vet, if the standard of care was not met. Prescribing the chewable formulation to a household with cats without adequate warning is the kind of fact pattern that could support such a claim.
- A complaint with your state’s veterinary licensing board.
Damages are limited in most states because animals are legally classified as personal property. Recovery is typically capped at economic losses such as veterinary bills and the fair market value of the pet, though some courts have begun recognizing higher “intrinsic value” awards for companion animals.
Long-Term Use and Cancer: What the Data Shows
Owners searching for an Apoquel lawsuit often have a separate worry: whether regular, as-prescribed use of the drug causes cancer. The label has always warned that Apoquel “may exacerbate neoplastic conditions,” and early anecdotal reports from veterinary dermatologists described young dogs developing fast-growing histiocytomas while on the medication.
The largest published study, a retrospective cohort of 660 dogs by Zoetis-affiliated researchers, found no statistically significant difference in cancer incidence between dogs on long-term Apoquel and those on other allergy therapies. Histiocytomas appeared in 5.6% of the Apoquel group versus 4.4% of controls. A separate comparison of 339 allergic dogs on long-term Apoquel found malignancy rates of 16.5% versus 12.8% in controls, also not statistically significant. Postmarketing surveillance covering more than 15 million treated dogs over 11 years shows an overall adverse event frequency of 0.025%, or about 2.5 per 10,000 treated animals. The most commonly reported events are diarrhea, vomiting, loss of appetite, and lethargy. Less common reports include elevated liver enzymes, skin infections, seizures, and low white blood cell counts. Zoetis’s published position is that “long-term or lifelong use per label instructions has a positive benefit–risk profile and is not associated with any cumulative safety risk.”
No class action currently seeks damages for cancer or other long-term effects allegedly caused by Apoquel taken as prescribed.
The Short Answer
If you were hoping to join an Apoquel class action over harm to your pet, there isn’t one to join. The pending Zoetis class action is a securities case for shareholders. The overdose data around the chewable formulation is real and growing, and it may eventually produce individual lawsuits or a future class filing, but the legal hurdles laid out in the Librela ruling explain why no such case exists yet. For now, pet owners with a specific injury are looking at individual product liability or veterinary malpractice claims, not a class.