Dogs and cats may ingest an object that can pass down the oesophagus but is unable to pass out of the stomach or along the intestine (guts). This is known as a gastrointestinal foreign body. Symptoms of this usually include vomiting, loss of appetite and depression. Urgent medical supportive care along with surgical removal is usually required to prevent possible blockage or perforation of the digestive tract, which might lead to overwhelming infection (peritonitis), shock and death.
The clinical signs of a pet having swallowed a foreign body are very variable and can range from no signs at all to signs of shock and depression due to obstruction of the intestine or stomach, or even intestinal perforation and subsequent peritonitis.
Symptoms that may be shown by a dog or cat following ingestion of a foreign object include nausea, acute and repeated vomiting of food or bile, loss of appetite, depression, and lethargy. Vomiting is the most common clinical sign. If the foreign object cannot pass into the intestine, it can remain in the stomach for a long period causing intermittent chronic vomiting.
Many foreign bodies enter the small intestine and the symptoms may resemble those of classic gastroenteritis such as vomiting or possibly diarrhoea. They cause irritation and partial obstruction of the digestive tract.
If the object becomes lodged and completely blocks the intestine, an urgent situation develops as the surrounding intestine deteriorates, and the animal’s condition may worsen rapidly. This can happen within hours of ingesting a foreign object or more commonly will happen later on and worsen over time. Vomiting can become persistent and if the pet is clearly unwell, with a very painful abdomen it is possible that the intestine has perforated. If this occurs, the pet will rapidly deteriorate, and can collapse and die if urgent veterinary attention is not given. Even if veterinary attention is given at this late stage, the pet is still at great risk; so it is always imperative that veterinary advice is sought as soon as possible.
The diagnosis of a gastrointestinal foreign body is made by the veterinary surgeon based on the symptoms, clinical signs and the history of possibly having ingested a foreign body. Sometimes the owner may have witnessed this, thus making the diagnosis easier.
Depending on the size and location of the foreign body and how slim the pet is, the object may be palpated or ‘felt’ though the abdominal wall. A string-like foreign body is far more difficult to detect on palpation. Sometimes it can be seen if a length is lodged under the pet’s tongue.
It will usually be necessary to take x-rays of the pet’s abdomen to confirm the presence of a foreign body in the stomach or the intestine. However, some foreign bodies are not visible on x-ray and other tests (ultrasound or special contrast x-rays) may be necessary.
Additional tests (e.g. blood tests) might be performed depending on the animal’s clinical condition.