How one biotechnology company is working to extend the lifespan of dogs

As research into the biology of aging advances, veterinary medicine is beginning to explore therapies designed not just to treat age-related disease, but to slow the process of aging itself. In this interview with dvm360, Brennen McKenzie, MA, MSc, VMD, director of veterinary medicine at Loyal, discusses experimental drug programs in development aimed at supporting healthy aging in dogs.

McKenzie outlines two programs Loyal is currently working on: medications that target growth-related hormones in large-breed dogs to slow accelerated aging, and a drug designed to address metabolic dysfunction to help delay age-related disease. Coinciding with this work, Loyal recently announced progress toward conditional FDA approval for LOY-002, a once-daily pill that targets age-related metabolic dysfunction in senior dogs. If approved, the Loyal says it would be the first FDA-authorized drug specifically indicated for lifespan extension in any species.¹

The following is a transcript of the video, lightly edited for clarity and cohesion:

McKenzie: Hi, I'm Brennen McKenzie. I'm a small animal veterinarian and I am currently both part-time in private practice, where I've been for almost 25 years now, and the director of veterinary medicine for Loyal, which is a biotechnology company based in San Francisco, [California]. Our mission is developing medications to try to extend the healthy lifespan of dogs.

dvm360: Are there any emerging therapies that you know of that support healthy aging in dogs?

Well, at Loyal, for example, we're working on a couple of different programs for medications to hopefully support healthy aging. One is looking at large-breed dogs. We know that the larger a dog is, the shorter their lifespan, and that's a consequence of the fact that we've bred them very intensively for body size, and a side effect of that has been a chronic overexpression of some growth-related hormones. Some of these very giant-breed dogs essentially have a growth disorder. We’ve created an acromegaly of a sort, and that has a lot of negative effects on the pace of aging. They age at an accelerated rate.

One of our programs is developing some medications to lower what's called insulin-like growth factor 1 (IGF-1). IGF-1 is one of those growth hormones. And if we can, after they're fully grown, if we can lower those levels for the rest of their life to something more like a small or medium-sized dog, we might be able to slow that abnormally accelerated aging. That's one program.

The other is a medication that we're developing specifically to target metabolic dysfunction. As I mentioned, we know from studies of caloric restriction that treating insulin sensitivity and other aspects of metabolic dysfunction is really effective in delaying age-related disease and extending healthy lifespan, but it's really hard to do that, both for psychological reasons, because food is love, and also because if you don't appropriately calorically restrict, you can overdo it and create malnutrition, which is not healthy. So we think that medications that mimic some of the same effects of caloric restriction may get some of those benefits as a safer and more practical strategy.

Reference

1. Coppock Crossley K. Lifespan extension drug in development for senior dogs reaches a new milestone. dvm360. January 13, 2026. Accessed January 13, 2026. https://www.dvm360.com/view/lifespan-extension-drug-in-development-for-senior-dogs-reaches-a-new-milestone