I’ve noticed that a couple of barn dogs like to eat HoofSnax or FlaxSnax if they are left within reach. I’ve wondered if the biotin in the HoofSnax would hurt the dogs in any way. Also I’ve noticed that the horses love dog Milkbones too. Would there be any problems with feeding the occasional horse treat to a dog or dog treat to a horse? Thanks, VC, Florida

Dear VC,

Generally, it’s best to feed treats and foods made specifically for a particular species of animal just to that animal and not to another species. This is because, even though dogs, horses, cats, and humans are all mammals, we’re each made and function a little differently and therefore we metabolize some ingredients a little differently. You may already be aware of some of these differences.

For example, I love chocolate! And it has no effect on me except to make me deliriously happy (and extra “curvy”). However, dogs metabolize chocolate into caffeine—which they are very sensitive to—and can develop serious heart and muscle dysfunction as a result. So, no chocolate for dogs. In the same way, my husband takes acetaminophen (Tylenol) for his aches and pains but we’re very careful to keep it away from our cat because this particular drug is toxic to the feline species. An example in horses is food or mineral blocks made for cattle may contain the growth promotant monensin (Rumensin) which can be fatal in equines.

So I don’t mean to scare you, but unless you carefully read the individual ingredients on the label of each product you wish to share among species—and diligently cross check it against the known toxins for that species—you might be setting up either your dogs or your horses for trouble. I suggest feeding the horses “horse treats” and the dogs “dog treats” (and the people “people treats”) unless you do your homework.

This week, I’ll do your homework for you! Here are the ingredients in HoofSnax:
wheat flour, ground flaxseed, stabilized rice bran, oats, brown sugar, vegetable oil, cinnamon, brewer’s dried yeast, artificial flavors, salt, rosemary, and biotin

I don’t see anything in this ingredient list that should be a problem for dogs. There’s 20mg of biotin (one daily serving for a horse) in 7 cookies, which means there’s about 3mg of biotin in one cookie. I looked on the label of a dog skin & coat supplement that contains biotin and a 50 lb dog would get 3mg per serving so this amount of biotin should be safe in a dog.

FlaxSnax has the same ingredients as HoofSnax minus the biotin.

Finally, about feeding Milk-Bones to horses. They contain:
wheat flour, wheat bran, beef meal and beef bone meal, wheat germ, milk, beef fat preserved with tocopherols, salt, minerals, chicken meal, malted barley flour, brewers dried yeast, sodium metabisulfite (dough conditioner), vitamins, poultry digest, dried cheese, natural and artificial flavor, malic acid, garlic powder.

Again, I don’t see anything that jumps out as toxic to horses, just some things they’re not used to eating, such as beef, chicken and other poultry, and dairy products. I have a horse with a very sensitive GI tract and I would not give a dog treat to him for fear of causing colic, diarrhea or other disturbances.