A newly published case series co-authored by ABVT diplomate Dr. Sara Lister documents the first reported cases of accidental oclacitinib (Apoquel®) toxicosis in cats—an emerging and potentially fatal hazard for curious felines.
The paper, "Severe Toxicosis Secondary to Accidental Oclacitinib Ingestion in Three Cats," appears in the Journal of Veterinary Emergency and Critical Care. Dr. Lister, of ASPCA Poison Control, authored the study with Dr. Jessica Kielb Basile of BluePearl Veterinary Partners.
The report describes three cats that each ingested large overdoses—more than 100 mg/kg—of oclacitinib chewable tablets, a Janus kinase (JAK) inhibitor approved for dogs. All three developed severe acute kidney injury along with systemic complications including ocular signs, low blood calcium, abdominal pain, and reduced urine output. Two of the cats died or were euthanized, while the third recovered fully after an extended course of intensive supportive care. Necropsies on the two deceased cats revealed renal tubular necrosis, though no definitive mechanism of toxicity was identified.
The authors note that the increasingly palatable chewable formulation has driven a rise in reported overdoses, as many cats readily consume large quantities. With no known antidote, treatment remains supportive, and the authors urge veterinarians to counsel owners to store the medication securely and to consider the less palatable tablet form in at-risk households.
For more information on this topic, visit ABVT's Oclacitinib Resource Page.