Here are some signs that your dog may have swallowed a nail:
* Vomiting
* Diarrhea
* Abdominal pain
* Lethargy
* Loss of appetite
* Difficulty swallowing
* Drooling
* Blood in the vomit or stool
If you see any of these signs, it is important to take your dog to the vet immediately. The vet will be able to determine if your dog has swallowed a nail and will recommend the best course of treatment.