Veterinary school warns of severe feline illness following ingestion of oclacitinib chewable tablets

Cheese, one of the patients who received treatment at NC State Veterinary Hospital after becoming severely ill from ingestion of oclacitinib chewable tablets. (Images courtesy of NC State University)

NC State College of Veterinary Medicine has issued an alert to cat owners who have dogs taking oclacitinib chewable tablets (Apoquel; Zoetis), as the school’s hospital has been seeing cases of severely ill cats following ingestion of the canine allergy medication. Recently, NC State Veterinary Hospital treated 2 cats that developed acute kidney injury and required hemodialysis to support their recovery after they ate the pork liver-flavored tablets.

“Previous reports of very high ingestions like this have resulted in death,” Tyler Johnson, DVM, DACVECC, a fellow in advanced emergency and critical care and extracorporeal therapies at the NC State Veterinary Hospital, said in the university alert.¹ “The incidence of Apoquel ingestion-related toxicity has increased at our hospital since the release of a chewable formulation that, for some reason, cats seem to be inclined to eat. Both of the cats we treated actively sought out the medication.”

Oclacitinib tablets are used to manage itching associated with allergic dermatitis in dogs of at least 12 months of age.² The medication is also intended for control of atopic dermatitis in dogs of the same age group.²

In NC State’s report, Shelly Vaden, DVM, PhD, DACVIM, a professor of small animal internal medicine at NC State’s College of Veterinary Medicine and president of the American College of Veterinary Nephrology and Urology as well as of the International Renal Interest Society, expressed the importance of client education on the dangers of Apoquel to cats, especially for families with cats and dogs in the household. She recommends prescribing dogs who live with cats the nonchewable form of oclacitinib tablets,¹ which would prevent the cat from accessing the medication.

“We’re hoping veterinarians start asking whether there are cats in the household before prescribing the chewable form,” said Vaden.¹ “We believe that households with cats should rely on the original, nonchewable form of Apoquel or be extra diligent in keeping the chewable form away from their cats.”

Yu Ueda, DVM, PhD, DACVECC, director of extracorporeal services and an emergency & critical care specialist; and Tyler Johnson, DVM, DACVECC, a fellow in advanced emergency and critical care and extracorporeal therapies; work together on a patient at NC State Veterinary Hospital.

Oclacitinib chewable tablets ingestion carry the risk of severe clinical signs in cats. In these felines, the medication can cause lethargy, vomiting, diarrhea, facial swelling, liver damage, and kidney injury. Some cats may even require intensive care hospitalization, according to NC State.¹ Cats who develop severe kidney injury may also need to undergo hemodialysis, like the 2 patients NC State treated.

Both of the patients treated at NC State experienced a full recovery following 4 dialysis treatments. Cheese, the first cat who received treatment at NC State for oclacitinib toxicity, underwent standard decontamination procedures—which include induced vomiting and administering charcoal—at his local veterinarian following ingestion. After his state did not improve, Cheese was referred to NC State. 

“I don’t think that our treatments for either of these cats did anything to remove the medication that they ingested, but what it did do is support their injury well enough that they were able to have a pretty quick recovery,” Johnson said.¹ “What we essentially did with dialysis was intervene for the kidneys that weren’t functioning well and allow time for those kidneys to recover enough to heal themselves.”

Cheese.

Although Cheese may develop kidney disease as an older cat, he is currently doing well and “it’s like nothing ever happened,” said Johnson.¹

To date, only a select group of veterinary specialty, referral, and academic hospitals in the US provide all types of extracorporeal therapy like hemodialysis, hemoperfusion or therapeutic plasma exchange to help remove toxins or other harmful substances in an animal’s bloodstream. From Washington DC to Florida, NC State is currently the only veterinary center that offers all forms of this therapy.¹

There have been no studies conducted that evaluate the effectiveness of this type of therapy to remove oclacitinib from the bloodstream—or even whether the therapies remove the drug from the bloodstream at all.¹ Still, according to NC State, Johnson is preparing a case study on the 2 treatments for publication, something the school says is “the first step leading to clinical studies and an official treatment protocol.”¹

“The scientific literature is very sparse,” said Johnson in the university report.¹ “We talked to poison control centers to see what they have amassed, and they will follow up with some of these cases to understand what happened to them. That’s where a lot of the information is coming from right now. Our case study demonstrates, at least for [the 2] animals that were severely affected, how we can successfully support them through it.”

Any cases of oclacitinib chewable tablets ingestion by a cat should receive immediate veterinary attention. “Decontamination procedures such as inducing vomiting and administering charcoal can be administered, but extracorporeal therapies may be required in cases of large ingestions,” wrote UC Davis.¹

References

1. Wheeler BE. Alert: NC State seeing cats severely ill from ingesting chewable allergy medicine for dogs. NC State College of Veterinary Medicine. August 5, 2025. Accessed August 14, 2025. https://news.cvm.ncsu.edu/alert-nc-state-seeing-cats-severely-ill-from-ingesting-chewable-allergy-medicine-for-dogs/
2. Zoetis announces FDA Approval of Apoquel® Chewable (oclacitinib chewable tablet) for control of pruritus associated with allergic dermatitis and control of atopic dermatitis in dogs. News release. Zoetis. June 13, 2023. https://news.zoetis.com/press-releases/press-release-details/2023/Zoetis-Announces-FDA-Approval-of-Apoquel-Chewable-oclacitinib-chewable-tablet-for-Control-of-Pruritus-Associated-With-Allergic-Dermatitis-and-Control-of-Atopic-Dermatitis-in-Dogs/default.aspx