Numelvi vs Cytopoint

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.

Cytopoint (lokivetmab) is an injection, not a pill. It's a lab-made dog antibody that grabs IL-31, the "itch cytokine" that drives so much of the itch in dogs, and takes it out of play before it can reach the nerves. It works outside the cells, not inside them like the JAK pills, and Zoetis says it has minimal impact on the rest of the immune system. Your vet gives it in the clinic.

Zoetis says one shot starts controlling itch within a day, and the 2023 AAHA guidelines put the onset anywhere from hours to 3 days. One injection lasts 4 to 8 weeks, and it's repeated every 4 to 8 weeks as needed, depending on the dog.

Cytopoint is priced by weight and only given at the clinic. Figure about $120 to $200 a shot for a 55 lb dog, from about $50 for small dogs and $200 to $300 or more for giant ones. At one shot every 8 weeks that's about $800 to $1,300 a year. These are rough 2026 US prices, and your clinic will vary.

Cytopoint has the fewest strings attached of anything on this page. The 2023 AAHA guidelines list no age limit and no health restrictions for it, and call it safe for puppies and for dogs with other illnesses, including cancer. In the US safety study, dogs on Cytopoint were also taking flea and tick products, antibiotics, steroids, vaccines and even Apoquel at the same time.

• In the US field safety study (162 dogs on Cytopoint, 83 on placebo), the only problems were at the injection site: about 6 in 100 dogs seemed sore after the first shot, versus about 5 in 100 on placebo. No allergic reactions to the shot were seen.
• Rare, 1 to 10 dogs in every 10,000 treated (from the UK label's reporting data): allergic reactions such as facial swelling, hives or anaphylaxis; vomiting or diarrhea; and neurologic signs such as wobbliness or seizures.
• Very rare, under 1 in 10,000: immune diseases where the body attacks its own red blood cells or platelets.
• Uncommonly, a dog's immune system makes antibodies against Cytopoint itself, and the shots stop working as well for that dog.