Not that anyone asked, but my favorite tree in the whole world is the oak tree. We have dozens of species of oaks in California, and where I grew up, in the great Sacramento Valley, the Valley Oak (Quercus lobata) is the most ubiquitous and also the largest oak tree around. They live to be hundreds of years old and grow into massive, photogenic shapes. When my husband and I bought the property where we have lived for the past (almost) three years, one of the key selling points was the magnificent hundred-year-old Valley Oak that stands in front of the house, and several other smaller Valley Oaks sprinkled around the property, along with some lesser oak varieties, the Blue Oak and the Live Oak.
Here’s the down side of living with oak trees, one that I never fully appreciated until now: acorns. So. Many. Acorns. And while all the oak trees are producing them, the Valley Oak makes some of the largest ones; they exceed the size of a standard tube of lip balm. Their distinctive “caps”, too, are a hazard. When they separate from the acorn, they become a separate large, hard, marble-shaped hazard.
Acorns underfoot on the lawn. (“Ow! OW!”)
Acorns getting mowed by the mower (turning the mower into a dangerous, projectile-throwing machine).
And worst of all: Dogs chewing on and (sometimes) eating the acorns.
California kids grow up with the information that the native indigenous people in California harvested the acorns and made them a staple of their diet – and every California kid who lives near an oak tree tries to reenact this. You gather acorns, peel off the skin to expose what appears to be a big, delicious nut, and find some rocks capable of grinding the nuts into a coarse flour. The goal is to then add some water and use your hands to mix the flour and water into a dough and try to make a tortilla. At some point in the process, you dip your finger into the flour and lick it, or take a little bite of the dough, and – ACK! Blech! It’s bitter!
When California kids get a little older, they learn that acorns are full of bitter tannins, and that the native people used to leach the flour with water, sometimes many times, to remove the bitter substance and make the acorns safe to eat.
And, as vet-bill-paying adults, we learn that in addition to being bitter-tasting, these tannins can be toxic to humans, horses, and dogs. Shoot!
Tannins in acorns can be toxic to dogs
I know several people whose dogs get sort of addicted to chewing the bitter-tasting nuts and end up with an extremely upset stomach – and in severe cases, kidney failure and death. A dog who becomes inappetent after eating acorns requires immediate veterinary care. My sister had a little dog who, at least once a year, would require a vet visit after sneaking a few acorns. She liked them after it had rained a time or two in the fall, when the nuts have gotten soaked with rainwater and fermented slightly – which seemed to increase their toxicity.
Despite the wealth of nuts littering my property in the fall, neither of my dogs has been interested in picking them up or chewing them, even speculatively, and up until now, neither have any of my foster dogs. That is, until my most recent foster dog arrived. I have to keep a very close eye on Coco, who has become inexplicably drawn to chewing on the acorns, to the extent that I basically can’t have her out of my sight on my fenced, two-acre property. Wah!
Like my sister’s dog from years ago, Coco is (thankfully) uninterested in the dry ones that cover most of my property, and is mostly drawn to the ones that have been soaked by the sprinklers on my front lawn. While this is quite a lot, given the GINORMOUS Valley Oak, the pride of our property, at least it’s just those. So it’s my new evening hobby: hanging out on the front lawn in the evenings with my dogs, throwing the ball for Woody, watching Woody and Coco wrestle, watching Otto watch for feral cats and squirrels … and picking up acorns from the lawn, and dumping them in our “green waste” barrel. I probably have a few more weeks to enjoy this new hobby before the tree’s supply is done and I can relax again.
Have you ever had trouble with an acorn-eating dog? Spread the word about this danger.
My miniature poodle, EmmieLou nearly died from chewing on acorns when she was 4 years old. It turns out that most of the acorns that have fallen in the rain are moldy and the aflatoxin is liver toxic. We have a red wood porch with a large oak tree overhead and a dog door leading to this porch. My baby presented with extreme lethargy and inappetence and I realized she was seriously ill. I rushed her to Sage Emergency in Concord, Ca not knowing she had been chewing on acorns. They determined that she was in liver failure with high liver enzymes in her serum and very low platelets. She received two transfusions and fluids for several days and they saved her 3K out of pocket. They are great there. The attending determined that she must have eaten an Aminita mushroom but I told him that was not possible since we had not walked in a month and her only access to the outside was the porch and not the yard— No mushrooms. I told him I had discovered chewed acorns with mold and that it must be Aflatoxin poisoning which gives the same liver damage as Aminita mushrooms. He scoffed at me and disregarded my observations. I insisted that this must be the case and said that it was important to note to help others and he still disregarded me. My Ph.D. from U.C. Berkeley in molecular bio research probably makes me more observant and intuitive than him so take it from me, moldy acorns on the ground can kill your dog. My Emmie’s liver made a full recovery and I now clear all the acorns from the porch.
My dog is eating pine nuts – is this OK??
Two words: Nut Wizard!!! I bought one a couple of years ago after a massive acorn crop; I love it!!! it works really well and it’s much better than raking.
What about acorns from Bay trees? We have some bay trees in the woods nearby, and my dog always picks up the dried acorns. So far he has never gotten ill. Are they toxic likethe acorns from the oak trees?
My mini schnauzer loves to eat acorns. We try to pick them up during the day, but she always seems to find them. We have too many oak trees to keep our yard acorn free. She hasn’t gotten sick yet, but I do worry that she will.
Hi Nancy, thanks for this article. I would like to add some very important information to it: WALNUTS and STRYCHNINE! We live in Lake County, home of walnuts and Pears. While we do have oak trees our dogs haven’t developed a taste for them (thankfully!) However, my female cattle dog mix Xena LOVES walnuts. And while the nuts themselves are not harmful their husks are! When the nuts drop they usually still have their green husk on which is full of a strychnine like poison. My vet tells me horror stories about the number of dogs she sees because of this. Liver and kidney damage can be the result of the worst of it. Xena tends to be chubby and it’s difficult to keep her weight down and as we know nuts are also full of fats that quickly add weight to her chubs. It’s a full time job to keep an eye on her and try to pick up all the nuts from several large walnut trees. They are our only source of shade and are lovely so I hate to even think about cutting them down. I felt this information may save a doggie life or two, so there you go. Thanks for all you do!
Thank you! I didn’t know about that! Today, we had a chimney sweep visiting and I was picking up acorns while he was working, and he mentioned that his business partner lost his dog to poisoning from eating green walnuts.
When my dog was a pup he would eat acorns and have an upset stomach every time. Now that he is an adult, he seems un-interested.
I have a 13 year old pit-bull mix we rescued as an adult. Her owner was incarcerated and she was left in the backyard to fend for herself until animal control picked her up. She was so skinny when we got her, you could count her ribs from a distance. We believe that’s what made her a scavenger. In any case, we realized this year that she was eating the acorns in our back yard, so we started picking them up. She had some pretty nasty poops, but no vet visits required. Thankfully. It’s good to know now that there is a real danger associated with them. We’ll remain vigilant. Thanks so much for the useful post.
*attracted
My dog ate acorns for 14 years. She cracked them and ate the inside. Leaving hundreds of acorn shells everywhere in the house. She never had any problems. This is the first year she hasn’t been attacked to them.