Kaleb, I hope you’ll agree, is a handsome beast. In his youth, he cut an athletic figure, and was quite the wanderer. Indeed, without his lust for independent travel, he’d never have come into our lives. Having roamed once too often from owners who showed little interest in taking him back, he ended up in a rescue shelter in Ithaca, New York, and was adopted in 2005 by my girlfriend, Nadia.

What I found was eye-opening. There’s scant evidence that either the supplements or the painkillers are doing much to ease Kaleb’s suffering. There is a treatment that clearly could do some good: a non-steroidal anti-inflammatory drug, or NSAID. But we’d rejected that after discussion with his vet a year or so ago because of fears—possibly overblown—that it might damage his kidneys.

If you have a pet, this should be a cautionary tale. Americans spent $14.2 billion on veterinary care for their pets in 2013—and that doesn’t include proprietary health diets and food supplements. Put another way, pet owners pay about $850 annually in veterinary expenses per dog, and about $575 per cat. Factor in the emotional energy we invest in keeping our companion animals healthy, and you’d hope for high confidence in the end results. But as I’ve learned, much of veterinary medicine is based on shaky scientific foundations: The drugs prescribed for your dog or cat may work no better than those we’ve been giving to Kaleb.

Now in his twilight years, Kaleb doesn’t get around so well. He’s part German Shepherd, and is afflicted by the breed’s curse: hip dysplasia and osteoarthritis. In plain English: his hip joints are loose, which leads to cartilage damage and inflammation. It’s painful to watch him struggling to his feet, and while he still loves to go for a walk, his back legs start to give out before too long. But at least he’s getting the best possible veterinary care, we told ourselves.

More: Too Often, the Drugs We Give Our Pets Don’t Work — Evidence Base — Medium