A few weeks ago, my Facebook page blew up with people sharing a particular post about the University of Minnesota College of Veterinary Medicine’s discovery of a new urolith (urinary stone) comprised of calcium tartrate tetrahydrate.

Image of struvite stones in a dog’s bladder

If you work in clinical practice in veterinary medicine, at some point you are likely to have sent bladder stones off to the Minnesota Urolith Center for analysis. Identifying the stone you’re dealing with is crucial to determining how to prevent future stone formation, often with specialized prescription diets. (The struvite stones depicted in the image above are ideally suited to control through diet) Because the MUC analyzes more stones than almost any other laboratory, they are in an unique position to identify early trends, and a few years ago, they began receiving new and unusual stones for identification. The new stones were comprised of choline and tartrate, but so few had been submitted, no one thought too much about it at first.

Then they began receiving more and more cases, mostly in small-breed, male dogs. MUC started collecting dietary information on the patients diagnosed with these stones, and they found a clear link between these uroliths and the use of choline bitartrate used in some of the more popular fresh food brands for dogs–such as Farmer’s Dog, JustForDogs, and NomNom brand foods. It is also commonly added to vitamin and mineral supplements available through such sites that help dog owners balance their homemade diets with a mineral mix. There have even been cases reported in humans taking supplements with choline bitartrate in them.

What is choline bitartrate anyway? It’s a salt of tartaric acid, making it a bioavailable form of choline in diets. Tartaric acid is the ingredient in grapes and raisins that make them lethal to pets, and ingestion of cream of tartar is also toxic as well! (I have a favorite holiday cookie recipe that calls for cream of tartar that I no longer make, as I consider the risk of accidental ingestion by one of the pets too great a risk) Choline bitartrate is not the same as tartaric acid, and yet clearly there are downsides of feeding it to our pets. To make matters more confusing, not all of the dog food companies studied specify what type of choline bitartrate is used in their brands, and it is possible that some types are safer than others.

The paper detailing the discovery of these stones and their link to choline bitartrate in the diet was first published in the Journal of Veterinary Internal Medicine in April 2025, but it wasn’t until a Facebook post by a veterinary clinic warning of the dangers of feeding fresh pet foods, such as the brands listed above, that information about this issue really took off on my social media. I don’t spend much time on Facebook, so I hadn’t run across the articles, but several people emailed me links, usually with the title “DON’T FEED FARMER’S DOG” in the subject line.

That’s how it was framed: Don’t feed X Brand, instead of “here’s an ingredient you should check to make sure is not in your dog’s food or supplements.” The pet food/pet influencer industry generates a lot of money, and it would be naive to think there aren’t people who have a certain desire to control the narrative. Especially when a single post can be so easily shared over and over again on Facebook. I came across a follow up post recently, in which the OP stated they were not advocating changing foods without talking to your veterinarian, but the odds are only a fraction of Facebook users saw that post.

The thing is, this warning isn’t meant to be an attack on a particular brand of fresh pet foods. I found choline bitartrate listed in certain lines of Wysong foods, as well as some lines of American Natural Premium foods, and several joint supplements, such as those made by MaxxiPaws. Ollie dog food listed this ingredient as well. It’s a recognition that we as pet caretakers need to be aware of this new issue and its cause, and take steps to protect our dogs, particularly if they fall into the higher risk categories of being a male, small breed dog.

I checked my own dog’s food after the Facebook post. I confess to a sigh of relief when I saw his food contained choline chloride and not bitartrate. The problem is, there will be no way of knowing moving forward if the type of choline bitartrate makes a difference and if companies have taken the steps to make this ingredient safer to feed.

I’ll be the first to state here, I am NOT a nutritionist. But there are some things I caution my clients about feeding their pets. There have been cases of raw diets contaminated with the bird flu killing cats, and the bird flu has been reported in cattle and swine as well as poultry. I’ve never been a big fan of raw diets, and given the FDA has scaled back its food safety inspections, I am even less likely to recommend feeding raw diets, particularly since recent events within the CDC make it doubtful bird flu is being closely monitored. With the rise in popularity of grain-free diets, we saw concerns about certain heart protective amino acids not being bioavailable in GF diets, thus showing a correlation in the increase of cardiomyopathy, particularly in dogs. I do not recommend grain-free diets for our pets, despite the fact that on any of the most popular “Ten Best Dog Foods” list, 90% of the foods listed are usually grain-free. I think the rise of the influencer culture has been a big factor in the increased popularity of these foods, as well as some of the negative marketing campaigns I’ve seen aimed at some of the big dog food companies (not that these companies are necessarily blameless when it comes to food safety).

So, you must realize here I am biased in my own way regarding pet foods. You must take anything I say with that in mind. But I will tell you that when I speak with veterinary nutritionists, dermatologists, and cardiologists, none of them recommend feeding BEG diets: Boutique, Exotic, Grain-Free. And every single cardiologist I have ever spoken with tells me the first thing they do when diagnosing a new cardiac patient is take them off BEG diets if they are being fed.

So for now, I’m going to continue to read my labels, and avoid any diets with choline bitartrate in them.