Numelvi vs Apoquel

Numelvi (atinvicitinib) is the newest. It's a once-a-day pill given with food, and it's more targeted than the older JAK drugs: it's built to block mainly one enzyme, JAK1. It's labeled for dogs as young as 6 months, younger than Apoquel or Zenrelia, and it has no vaccine warning; in its vaccine study, dogs on Numelvi responded normally to their shots. The catch is that it's new. Its field study ran only 28 days, and the label says it hasn't been studied in the field beyond that. I couldn't find a price I'd trust yet, so ask your vet's office.

• In its 28-day study (144 dogs on Numelvi, 144 on placebo): vomiting or nausea 6.9% vs 4.2%, ear infections 6.3% vs 5.6%, blood in the urine 4.9% vs 4.2%, poor appetite 4.2% vs 3.5%. Diarrhea was actually more common on placebo (10.4%) than on Numelvi (4.2%).
• Not for dogs under 6 months or dogs with serious infections. It may make infections more likely, including demodex mange and infected cysts between the toes, and new tumors have been reported in dogs on other JAK drugs.

Apoquel (oclacitinib) is a pill, and since 2023 there's a chewable version too. The itch messengers in allergic skin, including IL-31, the main itch signal in dogs, pass their message along inside the cell using enzymes called JAKs. Apoquel blocks those enzymes, so the message doesn't get through. It's not a steroid and it's not an antihistamine. It came out in 2013 and changed how vets treat itchy dogs.

It works fast. Zoetis says it starts relieving itch in as little as 4 hours, and in the label's one-week study, owners rated dogs on Apoquel less itchy than dogs on placebo on every one of the first 7 days. It's given twice a day for up to two weeks, then once a day after that, with or without food.

Figure roughly $80 to $110 a month for a 55 lb dog, and about $120 to $140 for the first month while it's given twice a day. That's about $960 to $1,320 a year. These are rough 2026 US prices, and your clinic and city will vary, so ask for a quote.

The label says Apoquel isn't for dogs under 12 months old, dogs with serious infections, or breeding, pregnant or nursing dogs. Because it changes how the immune system works, it can make a dog more prone to infections, including demodex mange, and it can make existing tumors worse. New lumps and cancers, both benign and malignant, showed up in dogs during the studies. The best long-term comparison, about 660 allergic dogs, found no difference in tumors between dogs on Apoquel and dogs on other treatments. Still, if your dog has had cancer or keeps getting serious infections, that's a real conversation to have with your vet before starting it.

• First 16 days of the label's atopic dermatitis study (152 dogs on Apoquel, 147 on placebo): diarrhea 4.6% vs 3.4%, vomiting 3.9% vs 4.1%, poor appetite 2.6% vs 0%, lethargy 2.0% vs 1.4%. Most of it settled down on its own while the dogs kept taking the pill.
• Counting everyone who got Apoquel in that study and its open follow-up (283 dogs), the most common new problems were skin infections (12%), lumps of various kinds (12%), ear infections (about 10%) and vomiting (about 9%). There was no placebo group to compare against for those numbers, so it's hard to say how much was the drug and how much was the allergy itself.
• In a follow-on study, 239 dogs stayed on Apoquel for an average of about a year. A small number developed tumors, including 6 dogs put to sleep for suspected cancers, and there was no comparison group. That's why the label tells vets to watch dogs on Apoquel for infections and new lumps.