Pecans, and walnuts too, are quite a treat for you and me but they can be toxic for dogs. We found out the hard way.
Our daughter raises Miniature Australian Shepherds and has brought the puppies to our house to run around and play in our yard which has a couple of gigantic pecan trees inside the fence. On one of their visits, we noticed one puppy not doing very well after being there for a while. He was very lethargic, drooling and had vomited, was having tremors, and didn’t seem to be neurologically sound. We thought he was having a seizure. A Vet couldn’t determine what caused it because, honestly, there are too many things it “might” be since puppies are known to play with, and eat, anything.
We did some research and found some disturbing things about pecans and dogs. Pecans have the compound juglone in them which is harmful to dogs (and horses too, by the way). Juglone can cause tummy problems and vomiting. If there is an aflatoxin or mycotoxin from Aspergillus mold on them, it can cause the symptoms noted above in my daughter’s puppy and also muscle weakness, fever, and seizures. Mold is more likely in nuts with shells still on, especially in damp conditions. In general, since pecans are high in fats and oils and dogs can be sensitive to foods with a high degree of fats, these nuts are not good for dogs.
We have older dogs and they eat pecans but have never had one symptom so we are inclined to believe puppies and their immature system might make them more susceptible to being affected. In our case, this beautiful puppy is just fine now. Keeping your dog out of the area where pecans fall is your first and best defense.
American Kennel Club article by Sassafras Lowrey, Nov 1, 2022.
https://akc.org/expert-advice/nutrition/can-dogs-eat-pecans/
Rogue Pet Science article “Can Dogs Eat Pecans? Here’s what to know”
https://agrilifetoday.tamu.edu/2020/11/09/the-nuts-and-bolts-of-pecans/