Dogs swallow everything from toys and fabric to corn cobs, bones and stones. The risk depends on the size, shape and material of the object, the size of the dog and where the object is. Signs of a blockage can include repeated vomiting, loss of appetite, abdominal pain, lethargy and less stool, but early on the dog may seem fairly unaffected.
Contact a vet as soon as you know your dog has swallowed something unsuitable. In some cases an object can be removed with endoscopy before it has moved further down, while other cases require surgery. X-rays and ultrasound may be used depending on what your dog swallowed and which symptoms it has.
Seek help quickly if your dog starts vomiting, is in pain, stops eating or becomes lethargic. Do not pull on string or other objects sticking out of the mouth or bottom, and do not make your dog vomit without a vet's instructions.