If the seeds are plain and unshelled, dogs can have pistachios as a small snack, but the risks of illness and choking hazard should have you looking elsewhere for a healthier treat.

Gabrielle Fadl, DVM and director of primary care at Bond Vet, says it's probably best for pistachios to remain a "once-in-a-while" treat for dogs rather than a consistent part of their diet. The faux-nuts do contain several health benefits for dogs, but they also possess high amounts of calories and fats that can upset your pups' digestive system. 

Plus, dogs can't eat pistachio shells because they can become an obstruction in their digestive system. Here's what else you should know about pistachios and dogs:

When Are Pistachios Bad for Dogs?

Pistachios can be unhealthy and dangerous for dogs when they're still in their shells and coated in flavoring. However, even when they're plain, too many pistachios can put your dog's health at risk. 

The seeds, even without shells, can become lodged in a dog's throat or intestine, Fadl says. That's especially true for small dogs. 

Pistachio flavoring is another worry. Onion and garlic, for example, are toxic for dogs and can cause life-threatening anemia. Non-toxic flavors or salted pistachios can still upset dogs' digestive systems, and even plain pistachios can, too, Fadl says. It all depends on the individual pup. 

Plain, unshelled pistachios are the safest for dogs, but even they aren't without risk. Too much of the high-calorie snack can contribute to obesity, and there are serious, long-term risks, too.

Pistachios' Links to Canine Pancreatitis, Liver Disease

Too many pistachios or older, moldy pistachios can put your dog's health in serious danger. These cases are rare, however, and might only occur if your dog gets into a bag full of pistachios. 

"Although the fats in nuts are considered ‘healthy fats,’ they can still contain more fat than is healthy for dogs to ingest," Fadl says. 

That's why too many pistachios can lead to pancreatitis, a sometimes life-threatening affliction that requires immediate veterinary treatment. 

Pistachios past their expiration date can develop mold, which in turn can release aflatoxins, Fadl says. Though rare, those are toxic to dogs and can cause liver disease.

This is why it's important to keep all snacks securely away from your pups, especially if they're counter-surfers. If your dog consumes a large amount of pistachios or flavored pistachios, call your veterinarian right away. 

If your dog is seriously ill, head to your nearest emergency veterinarian or call a pet poison hotline.

When Are Pistachios Good for Dogs?

All that said, pistachios can have some health benefits for dogs because they include protein, vitamins, minerals, and fiber, Fadl says, adding that their "healthy fats" can in theory improve skin health and limit inflammation.   

But dogs can eat pistachio nuts in moderation only. Fadl says giant breeds might be able to have up to 10 pistachios per day while small dogs should only eat one per day. Basically, it depends on the size of your dog. 

Be sure to talk to your veterinarian before feeding your dog pistachios. With so many risks involved, it's probably best for you to keep pistachios to yourself and feed your dog a different treat.

Can Dogs Eat Other Nuts?

Pistachios aren't the only nut to keep an eye on when it comes to whether dogs can eat nuts. Macadamia nuts are toxic to dogs, so avoid them and their brethren: English walnuts, horse chestnuts, ginkgo nuts.

Pecans are also toxic for dogs, and our pups should avoid walnuts, too. 

Almonds, cashews, and peanuts might be safer for dogs, but they can still make your dog ill. It's probably best to avoid giving nuts to your dog in general.