A new study out of North Carolina State University, published in JAVMA, put an AI-enabled digital stethoscope through a head-to-head test against real clinicians, and the results are a useful reality check for anyone eyeing these devices as a shortcut. Researchers had a board-certified cardiologist, a cardiology resident, and a fourth-year veterinary student examine 105 dogs and cats using the same AI-powered device, then compared the device's readings against what the humans actually heard.

The device held its own in some respects: it caught 87% of canine murmurs and matched the fourth-year student's performance almost exactly. But its specificity in dogs was weak (56%), meaning it flagged a lot of healthy hearts as suspect, and in cats it fell apart entirely, catching only 2 of 22 murmurs. It also classified every single dog in the study as having some form of arrhythmia, which is the diagnostic equivalent of a smoke detector that never stops beeping.

The device in question is built and marketed for human use, and that's the real story here. "Universal" instruments assume a universal patient, and cats in particular seem to break that assumption. For practices weighing whether to add AI-assisted auscultation to the toolkit, this is a useful reminder that experienced ears still catch what the algorithm misses, especially in the species the device wasn't built for.

Johne's disease has a diagnostic problem that has outlasted decades of testing: infected cattle can carry Mycobacterium avium subspecies paratuberculosis for years while shedding little to nothing detectable, which means conventional fecal culture and antibody tests routinely miss early infection. Researchers at the Australian Centre for Disease Preparedness took a different approach, screening cattle blood for a signature of three circulating microRNAs instead of hunting for the pathogen itself.

The results are promising on paper. The microRNA panel hit 92.8% sensitivity and 94.8% specificity, comfortably ahead of the combined reference tests used for comparison. It's not a finished product yet as the study was small, the infected and uninfected cattle came from different herds and breeds, and there's no evidence yet that the test can catch MAP during the earliest, most contagious window of infection. Still, if a follow-up study can show early detection, this could give herd veterinarians a genuinely better tool for a disease that has quietly frustrated the industry for years.

We cover a lot across veterinary medicine, science, and the broader animal kingdom in this newsletter. But when vet med is your 9-to-5 (or longer), and you're reading this deep into a weekend newsletter, you might want a palate cleanser.

That's why we're trying something new: every week, we'll recommend something decidedly not about veterinary medicine. We got the idea from one of our favorite podcasts. At the end of every episode, the hosts give what they call "carve outs," a chance to shout out anything else they've been enjoying, no matter how unrelated it is to the episode's subject matter.

Since we're stealing their idea, it only feels right to start our new segment by shouting out the podcast itself: Acquired. Acquired tells the stories and strategies of the world's greatest companies through deep dives (often over four hours long) into a company's history, from founding to today. The dedication and research hosts Ben Gilbert and David Rosenthal put into each episode is incredible, and we've learned a ton from it.

Some of our favorite episodes cover Costco, Ferrari, Coca-Cola, Taylor Swift, and Trader Joe’s. Their most recent two-part episode on Disney pulls back the curtain on all the Disney magic, and if you’re a sports fan there are fantastic episodes on the NFL, Formula 1, and Indian Premier League Cricket.

I know we said we'd keep this about anything but vet med, but their episode on Mars was too good to leave out. It’s mostly about the chocolate empire, but does touch on their vet med business, since nearly 60% of Mars’ revenue now comes from the pet care business, and 40% from snacking.

Go find Acquired on Apple, Spotify, or wherever you get your podcasts. Let us know if you enjoy it as much as we do!

Here are some of the other stories that caught our eye and we're following this week from around the veterinary world and animal kingdom: