Orchid and his person, Marissa Fiene

Photo by Allie Culver

Marissa Fiene lost her cat, Orchid, last month after the cat overdosed on a flavored allergy drug prescribed to a dog in the family. Fiene posted on Reddit, "I've been messaging vets, vet schools, shelters, adoption agencies, friends, everyone I can think of, to inform them about the dangers of these chewable tablets. If we had known, maybe things would have been different."

Apoquel, a drug for skin allergies in dogs, came out two years ago in the United States in a chewable form flavored with pork to make it palatable. It's proven to be that, to an extreme.

Two separate organizations that operate hotlines for pet poison emergencies report a rising trend in overdoses in dogs and cats, who are breaking into the packaging and gorging on the contents.

Some reportedly have consumed 100 or more tablets. Greatly overdosing on the drug can bring on any of a variety of clinical signs, including vomiting, eye redness, swelling of the face, and effects on the cardiovascular system, central nervous system, kidneys and liver. Some animals have died.

Veterinary toxicologists and emergency care practitioners are trying to spread the word about Apoquel Chewable's strong allure to pets to ensure that the people giving the medication make a concerted effort to safeguard it.

Apoquel, which contains the active ingredient oclacitinib, is hardly the first pet drug to be made flavored and chewable, but it's evidently unusually enticing, according to veterinarians who have dealt with overdose cases.

"It's common sense to keep medications out of the reach of pets. Obviously, people know that," said Dr. Sara Lister, a toxicologist at the ASPCA Animal Poison Control Center. "But I think emphasizing it for this one would be helpful — if we can have vets just tell owners, 'They seem more likely to seek it out compared with other flavored medications.' "

Case in point: On Christmas Day 2023, one or both of the clinic cats at Juniata Veterinary Clinic in Pennsylvania somehow scaled a set of shelves to reach a container of Apoquel Chewable stored more than six feet up. After knocking the container to the floor, Mittens and Golly devoured an estimated 110 16-milligram tablets between them. (A single 16-mg tablet is the standard dose for a 60- to 89-pound dog.)

Golly, then 11, and Mittens, 13½, were treated with intravenous fluids and other supportive therapies. Jessalyn Jones, a veterinary technician, lingered after her shifts, tearfully monitoring the cats and spoon-feeding them. It took about a month for the cats to overcome injury to their kidneys.

At the time, Apoquel Chewable had been on the market for a couple of months. The intensity of its appeal wasn't understood, and the cats had never broken into other flavored medications kept in the clinic. The team chalked it up to an oddball event, maybe instigated by Golly, who has a reputation as a glutton.

As Dr. Karen Rosenberry, a veterinarian at the practice, said, "We figured it was because our cats are the way they are."

It turns out that theirs were early cases in an unfolding trend. Lister at ASPCA poison control said that during a typical 10-hour shift staffing the hotline now, she alone will field two or three calls about Apoquel overdose.

New formulation of an established drug

Apoquel is approved for use only in adult dogs to control itching associated with allergic dermatitis and to control atopic dermatitis. Some veterinarians prescribe the medication for cats on an extra-label basis.

Made by Zoetis, the original, unflavored formulation debuted in the U.S. in 2013. Ten years later, in June 2023, the U.S. Food and Drug Administration approved Apoquel Chewable. The pork-liver-flavored drug reached the market in October that year. The labeled dosing is 0.4 to 0.6 milligrams per kilogram of body weight administered twice a day for up to two weeks, then once a day thereafter.

Staff at two pet poison advice centers — the ASPCA's, which is based in Illinois, and the Pet Poison Helpline, based in Minnesota — noticed an uptick in calls about accidental overdoses after the flavored formulation came out. And unlike overdoses of the original formulation, which usually involved a few pills, the scale was much greater. Both centers have published recent papers on the topic.

Veterinarians at the Helpline reported in the Journal of Medical Toxicology in April that they received a nearly threefold increase in Apoquel overdose calls in the year following the October 2023 debut of the chewable tablets compared with the preceding year.

Their director of veterinary medicine, Dr. Renee Schmid, said by email that the numbers continue to rise, with calls in 2025 so far surpassing those in 2024 by about 10%.

ASPCA poison control reported in a brief communication published in the Journal of Veterinary Emergency & Critical Care in April that "household pets are ingesting larger quantities and are experiencing signs of toxicosis that have not been noted previously."

Lister, lead author of the communication, followed up with a presentation on Sept. 5 at the International Veterinary Emergency and Critical Care Symposium. There, she reported that from June 2023 through mid-March 2025, the center logged 3,029 overdoses in dogs and 307 in cats, the vast majority involving the chewable formulation. Among the cases, 36 resulted in death.

By comparison, from December 2013 through May 2023 — a period of nearly 10 years before the chewable form was available — the center logged 2,016 overdoses in dogs and 212 in cats, with no deaths.

Lister reported that overdoses before Apoquel Chewable debuted typically amounted to accidental double doses given, a pet consuming a dose meant for another pet, or cats eating medication tucked in Pill Pockets or food. "So," she noted, "they [were] not eating large quantities of pills 'unassisted.' "

Dogs and cats appear to be much more motivated to get at Apoquel Chewable. In a case report published in June by the Journal of the American Veterinary Medical Association, a 77-pound dog experienced acute kidney injury after consuming a full 60-count bottle of 16-mg tablets. "The bottle had been part of a package delivery, and the patient chewed both the box and bottle open while on the front step," the authors wrote.

Apoquel Chewable

Photo by Jessalyn Jones

Apoquel Chewable is flavored with pork liver and brewer's yeast, according to the maker, Zoetis.

Too much of a good thing?

An early case of overexposure to the drug occurred during a palatability study by Zoetis. According to a paper published in 2022 in BMC Veterinary Research, one of the client-owned dogs in the study had to be withdrawn because of an acute exposure. "The enrolled dog, and potentially her housemate, consumed 50 tablets after gaining access to where the chewable tablets were stored," the researchers wrote. They added: "Follow-up examination and clinical pathology results did not report any adverse health events due to the acute exposure."


Authors of the palatability paper explain that veterinary pharmaceutical companies make flavored, chewable formulations to help pet owners comply with prescribed therapies, to reduce the stress on the pet and the owner associated with pilling their pet, and to "make the overall medication experience more reminiscent of the pleasurable experience of giving the dog a treat."

Zoetis told the VIN News Service in an email from spokesperson Jeannie Neufeld that the flavoring in Apoquel Chewable is pork liver and brewer's yeast. "Pork liver is used in other Zoetis chewable products in a formulation that is slightly different than Apoquel Chewable," Neufeld wrote.

The email notes that the package insert and label on Apoquel Chewable directs users to keep the drug "in a secure location out of reach of dogs, cats and other animals to prevent accidental ingestion or overdose" and reminds pet owners to replace the lid or close the carton.

The message advises further: "Cat owners should keep in mind that cats can get to areas, such as countertops, that may be safe from dogs."

Apoquel Chewable is sold by Zoetis in 250-count bottles with child-resistant caps or in boxes containing 10 blister packs of 10 tablets each. Zoetis said both packaging types "are designed to ensure product integrity and safety" and added that it is "committed to ongoing evaluation of packaging and product safety to balance accessibility for intended users with measures that reduce the risk of accidental ingestion by pets other than those prescribed."

The company said reports of Apoquel Chewable overdoses among dogs and cats are "very rare," a classification it applies to incidents occurring in fewer than one out of 10,000 dogs treated in a 30-day period.

In the U.S., the FDA has received 195 reports of accidental overdoses of Apoquel Chewable in dogs and 70 reports in cats from June 1, 2023, to Sept. 1, 2025.

That's notably fewer than the number of overdose cases fielded by ASPCA poison control. The FDA derived its figures by reviewing the narrative section of adverse event reports and might not have captured all such incidents "because of the phrasing or brevity of the narrative section," according to an email from the Department of Health and Human Services in response to a query from VIN News. The agency added that there may be incidents that have gone unreported for a variety of reasons, including that the owner didn't know it should be reported or how to report.

Intensive care sometimes needed

While patients have recovered with fluids and supportive care alone, sometimes more intensive treatment is necessary. The veterinary hospital at North Carolina State University this year provided hemodialysis to two cats that went into kidney failure following overdoses of Apoquel Chewable.

In both instances, the cats — a 2-year-old orange tabby named Cheese and a 3-year-old gray tabby named Buddy — got into a canine housemate's bottle of medicine on the kitchen counter.

Cheese

Photos by Julia Williamson

Cheese traveled 265 miles in March from his home in Greenville, South Carolina, to North Carolina State Veterinary Hospital, where he received four hemodialysis treatments to support his body while his injured kidneys healed. Today (right), he is back to his social, cuddly self, his owners say.

In Cheese's case, the first sign that something was amiss happened on a Saturday in March. Harrison Williamson, one of the cat's owners, said he suddenly heard Cheese "violently throw up in ways I'd never heard before."

When he realized Cheese had gotten into the dog's allergy medication, he "started freaking out," called his wife, Julia, who was out of town, then rushed the cat to an emergency hospital. The Williamsons later estimated that Cheese had ingested 70 times the therapeutic dose.

His kidney function poor and declining, Cheese was referred the next afternoon by their local ER in Greenville, South Carolina, to the veterinary dialysis center at NC State in Raleigh, 265 miles away.

"They handed me Cheese and said that at any time, he could go into cardiac arrest," Harrison recounted, describing the cat as "very lethargic" with a swollen face and bloodshot eyes. During the 3½-hour drive, Harrison said, "I kept my hand on him to make sure he was breathing."

Cheese was hospitalized for 10 days and received four sessions of dialysis. Once home, he had to be fed and medicated through a tube for a few more weeks.

Julia Williamson noted that their dog, Kobe, had been taking Apoquel for nearly four years, the regular formulation for most of that time. He switched to Apoquel Chewable at the start of the year when his veterinarian stopped carrying the original form. "To me, it didn't matter that it tasted good," she said. "That was their only option."

Since the harrowing experience with Cheese, the couple has taken Kobe off Apoquel altogether, opting to try other ways to quiet his itch. Julia Williamson is soured on palatable drugs. "Even with humans, I don't think that medicines should taste good," she said, noting that some antacids are so tasty, "you can just pop them like candy."

The second cat seen at NC State, Buddy, lives in a household in Augusta, Georgia, with two other cats and two dogs. One of the dogs had been taking Apoquel Chewable for about four months when Buddy apparently got into the container. His owner, Alison Gault, said her husband found the bottle on the floor, open and broken, one morning in July. Two tablets remained when there were supposed to be 17.

Buddy

Photo by Alison Gault

About eight hours after he consumed an estimated 15 16-mg tablets of Apoquel Chewable, Buddy threw up, hid and his third eyelid appeared, suggesting something was amiss.

The couple took Buddy and a second cat that they thought might have partaken to their regular veterinarian. Over a few hours' observation, the cats seemed fine and were sent home.

But eight hours after the incident, Buddy's eyes started looking strange. His third eyelid appeared, he threw up, was lethargic and hid under a bed. The Gaults took him to an emergency hospital, where he stayed overnight. Like Cheese, his kidney function went from bad to worse, and they were referred for dialysis.

During his 10-day hospital stay, Buddy also had fluid removed from around his lungs, treatment for pancreatitis and a blood transfusion to counter anemia. Once home, he, too, temporarily required a feeding tube.

Gault reported that Buddy is back to his old self now. Her dog, like the Williamsons', is no longer on Apoquel. "I couldn't bring myself to bring it back in the house," she said.

The family will be paying off the $27,000 they amassed in veterinary bills for a while, but "Buddy's alive," Gault said, "so it was worth it."

Orchid wasn't as lucky. A 5-year-old cat belonging to Marissa Fiene and Allie Culver in Kansas City, Missouri, Orchid died in August after eating as many as 29 16-mg tablets of Apoquel Chewable. As in other cases, the bottle, kept on the kitchen counter, was discovered on the floor, open and empty.

Although she received immediate veterinary attention at an urgent care, then at an emergency and specialty hospital, Orchid's condition was dire. She developed a heart murmur, had difficulty breathing and stopped producing urine, a cascade of events within two days of the overdose that led to a decision to euthanize her.

Orchid's regular veterinarian, Dr. Rochelle Clark, said her clinic has carried the chewable tablets for two years. "This is the first time I've had any issues," she said.

Alarmed by what happened, Clark requested Orchid's medical records from the hospitals where she was seen. Clark reported the incident to Zoetis, and she now makes sure that clients with Apoquel Chewable prescriptions are alerted to store the medication securely. She has "NOT SAFE FOR CATS" written on every bottle dispensed from her clinic. Clark knows the drug is sometimes prescribed to cats extra-label, but she chooses to err on the side of caution.

The nature of the drug

Oclacitinib, the active ingredient in Apoquel, inhibits Janus kinase (JAK), a family of enzymes involved the body's immune response that promote inflammation, itching and pain. The FDA has approved a variety of JAK inhibitors for people to treat conditions including rheumatoid arthritis, Covid-19 and certain blood cancers. Apoquel was the first JAK inhibitor to be approved for veterinary use. Last year, a second JAK-inhibiting allergy drug for dogs was approved, ilunocitinib (brand name Zenrelia). It comes in one formulation, unflavored.

ASPCA poison control reported in its paper that ingestion of 10 to 15 mg/kg of oclacitinib have resulted in gastrointestinal, cardiovascular and central nervous system signs in both dogs and cats, and dosages of 12 to 38 mg/kg have resulted in acute kidney injury in both species. Because severe overdoses are relatively new, veterinarians are still working out the mechanisms behind the health effects seen in exposed animals and how best to treat them. 

Dr. Tyler Johnson, an emergency and clinical care specialist at NC State, said when the hospital received the first call about a cat with significant kidney injury from Apoquel Chewable, their reaction was, "Oh, that's odd."

"We don't really understand why some of these cats are getting such a significant kidney injury," Johnson said. "The receptor that the drug is acting on is found on pretty much every tissue throughout the body and is responsible for helping to mitigate inflammation."

While dogs can become quite sick from overdose, cats are drawing particular attention, in part because they're usually smaller and may be exposed to higher doses relative to their size, and because their physiology is different.

"Cats don't metabolize drugs as readily as dogs," said Dr. Tina Wismer, a toxicologist and senior director of ASPCA poison control, explaining that as obligate carnivores, cats as a species haven't been exposed to as many toxicants as omnivores like dogs. "Cats are missing major metabolic enzyme groups," she said.

Plus, unlike dogs, cats do not have a reputation for indiscriminate eating. "We always expect dogs to eat chewable medications," Wismer said, "but cats, they're usually pretty selective in what they eat."