Some dogs are picky eaters who will graze over a bowl of food all day and turn away most fruits and vegetables you offer up. And other dogs are major scavengers who will eat any food or food-like substance that crosses their path.

When your dog is walking ahead of you and finds some unknown substance to quickly sniff and swallow before you can reach them, should you be worried? Might the food have been spoiled or unsafe for dogs? These are possibilities, but so are the alternatives. They likely found a harmless little mid-walk snack. But for the dog parents who do worry (as many of us do), here are some thoughts from vet professionals to guide you and hopefully put your mind at ease.

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Be prepared for your dog to find snacks 

If you know your dog is among the garbage disposal, will-eat-anything category, try to be prepared on walks. Keep your dog close to you. If they’re too far ahead it’s easier for them to find a little treat and scarf it down before you can even catch up and see what it was. If they’re closer you also have a chance of grabbing the food before it’s swallowed. Whenever possible, try to pry open their mouth and scoop out the mystery item, gross as it may be. If you are able to get it out, you might be able to identify if it was anything harmful.

Related: Yes, Your Dog Can Get Too Many Walks

Alternatively, knowing your dog is food-motivated, bring some favorite treats on walks. If they grab something, immediately get a tasty treat from your pocket and see if you can make a trade. Reward them for dropping the mystery item. You can also train a “drop it” command ahead of time.

Here’s when you should worry about the snacks your dog finds

How concerning your dog’s constant walk snacking is depends entirely on what they grab. If they happen to come across an animal carcass and take a bite, you likely have no reason to be worried. They may have some gastrointestinal discomfort for a day or so, but there shouldn’t be any long-term issues. However, if they do snack on carcasses, get a deworming pill if they aren’t already on one.

There are a few key items you really don’t want your dog to eat, especially without your knowledge. These are:

• Grapes/raisins
• Bones
• Garlic/onions
• Sago palm
• Chewing gum

All of these can be harmful or fatal to dogs. If you aren’t sure what your dog ate and it might be one of these items, stay calm, but pay attention for several hours. If you notice any vomiting, diarrhea, abnormal lethargy, neurologic symptoms, or excessive drooling, call your vet right away. If you’re still on the walk and know they ate something harmful or they have immediate symptoms, get to the car and to the vet right away.

Usually, your dog’s sporadic street snacking won’t lead to anything besides a happy pup and perhaps some GI troubles. But even so, it’s better to be safe than sorry, so being prepared and keeping an eye on your dog after they sneak outside food is always the way to go.

Read Next: How to Take a Safe Trip to the Dog Park

Top photograph: Chalabala/Getty Images