Short answer
Pistachios are a common hidden ingredient in many packaged foods that dogs might snatch, including trail mixes, granola bars, certain cereals, baklava, biscotti, ice cream flavors, and some stuffings or pesto sauces. The bigger risk with these items isn't just the nut itself, but that they're often heavily salted, covered in chocolate, or mixed with raisins—all of which are toxic. Always check ingredient lists on packaging left within reach, and be extra cautious with shared desserts or party snacks.
Pistachios — Food safety facts
Feed with care · Dogs · full breakdown on the linked food page
Usually salted, and the shells crack into sharp pieces. Avoid.
The full verdict, portion guidance and serving notes are collected on the Pistachios food facts page.