Foreign Body Removal
There are many objects a dog can swallow that cannot be passed through the whole intestinal tract. When this occurs, it can be a medical emergency and requires removal as soon as possible.
Here at Queensland Veterinary Specialists, we often get referrals for animals needing medical intervention after ingestion of a foreign body.
Common types of foreign bodies
You may be surprised to hear the kinds of things animals can swallow. Most commonly, we see referrals for swallowed bones, fabric (e.g. bedding, clothing), fish-hooks, corn cobs or large seeds (e.g. peach seeds). Even tampons, nails or needles can be swallowed and wreak havoc. Sometimes thin objects (string or hair) which would normally pass through gets lodged on something firm and results in a linear intestinal foreign body and plication (folding) of the bowel.
When the object in question is swallowed, it can get stuck before it gets to the stomach (that is, in the oesophagus) or it can end up in the stomach. The animal will generally attempt to vomit up the object, and in most cases this is successful. However, if the object cannot be brought up and blocks the normal flow of food and water, it can become a life-threatening problem.
Common signs of foreign bodies
Occasionally, the only sign may be that the owner saw their pet swallow a foreign object. If nothing has been witnessed, then signs generally occur due to blockage of the digestive tract, which can occur within minutes or days. Signs include:
- Vomiting, retching or regurgitating
- Salivating
- Inappetence (not wanting to eat)
- Abdominal pain
- Lethargy, dehydration and collapse in severe cases
How is an obstruction diagnosed?
Once your pet has been admitted, a thorough examination will be completed. This includes a physical examination (evaluation of the hydration status, vitals, and abdominal palpation), blood tests and other procedures to help identify the problem. These may include:
- Radiography (X-rays) – A useful tool to undercover gas dilatation of the intestinal tract and to discover foreign materials such as metals or bones.
- Ultrasonography – Compared to radiography, it is helpful in the examination of intestinal wall layers (there are four layers to the bowel), bowel motility (movement of food), and other abdominal organs. Foreign material such as fabric or plastic can be found this way. Ultrasound is also useful in identifying other intra-abdominal concerns.
Abdominal ultrasound is most commonly employed to identify the presence of a foreign body, and its location in the abdomen. It has the added advantage of being able to assess the other abdominal organs (liver, spleen, kidneys, bladder, adrenal glands), and to assess for other possible intra-abdominal concerns such as perforations or presence of free fluid or gas in the abdominal cavity.
One limit of abdominal ultrasound is if the animal has food in their stomach, it can be difficult to distinguish between foreign material or normal food. Repeating the ultrasound hours later may be useful in these situations.
Radiographs (X-rays) can be performed of the chest or abdomen. Chest radiographs are generally used to diagnose foreign bodies in the oesophagus. This can be used to confirm how far along the foreign body is within the oesophagus and can also give information of what type of foreign body it is (metal, bone, fabric/soft tissue). This may also indicate how difficult it could be to remove. Radiographs can also give information on possible complications, such as pneumonia (from aspiration of vomit), or free gas/fluid where it shouldn’t be (such as the space between the lungs and chest wall) which can indicate a rupture of the oesophagus.
Radiographs can also be performed on the abdomen, especially if the foreign object is metallic or bone. They can show you if the foreign body is causing a complete blockage of the gastrointestinal tract.
Unfortunately, some objects cannot be seen on radiographs (such as some fabric foreign bodies) and so endoscopy may be required to both diagnose and resolve the problem.
Treatment
Once a foreign body is diagnosed, surgery to remove the obstruction is often required. This typically involves making an incision through the abdominal wall and examining the entire gastrointestinal tract (by sight and feel) to find the foreign body. The material may be removed by one of the following (or combination) of procedures:
- Enterotomy – The intestinal wall is incised (cut open) and the foreign body will be removed. The incision wound is then closed with sutures
- Enterectomy – If a certain section of the intestinal wall is very unhealthy, an enterectomy (remove a section of the intestine) will be performed. The resected ends of the intestines will then be reconnected where there are healthy tissues
- Gastrotomy – An opening in the stomach to facilitate removal of the material. The opposed ends of the linear incision are then closed with suture material
When is Endoscopy used?
Endoscopy is used to identify and remove the foreign body in the following situations:
- A foreign body is identified in the oesophagus
- A foreign body is in the stomach and is causing clinical signs (vomiting, abdominal pain, inappetence)
- A foreign body is in the stomach and is at risk of causing a perforation (e.g. sharp objects such as needles)
- A foreign body is in the stomach and is at risk of causing harm or death to the patient (e.g. batteries)
When Endoscopy may not be used
- If the foreign body in the stomach appears too large (e.g. large rock or hair ball), then surgery is often recommended
- If the foreign body has moved past the stomach into the intestinal tract, then surgery is required if it is causing an obstruction
- If the foreign body can be removed by inducing vomiting (e.g. small and not too sharp)
- If the foreign body is not causing clinical signs and is considered likely to pass through without consequence, a ‘wait and see’ approach is occasionally employed
Foreign body removal
An Endoscopy has to be performed under a general anaesthetic. Often pre-anaesthetic bloodwork is performed to ensure electrolytes, kidney values and other parameters are normal. The patient may require some fluid rehydration prior to anaesthesia, especially if protracted vomiting has occurred.
Endoscopy involves using a long, flexible scope, with a video camera at the end so that the image can be seen on a TV screen adjacent to the patient. The veterinarian is able to pass the scope down the oesophagus, into the stomach and even the first part of the intestine. Once the foreign body is identified, graspers or wire loops are fed through a channel in the scope and are used to grasp the foreign object which can then be carefully dislodged and removed via the mouth with the scope. For foreign bodies in the oesophagus, larger graspers are often employed and are inserted beside the scope.
Benefits of Endoscopy
Removing objects using a scope is often less invasive and results in a speedier recovery for patients than surgical removal. Removal can often be faster than surgery (although this can vary depending on the type of foreign body). Generally, the procedure is also a cheaper option than surgery.
Risks of Endoscopy
As the patient is anaesthetised, the normal risks associated with general anaesthesia should be considered.
Once removed, especially if lodged for a prolonged period of time, the underlying tissue can be damaged and result in inflammation and ulceration. If this occurs in the oesophagus, then a possible complication is scarring of the food tube, resulting in formation of a stricture (narrowing of the oesophagus) which may require further intervention.
There is also a risk of oesophageal or gastric perforation (tears), especially if the object is sharp. In these cases, the patient may require emergency surgery.
Post procedural care
- Endoscopy – The majority of patients with endoscopically removed foreign bodies go home the same or following day. We may elect to send them home with some antacids or gastroprotectants, anti-nausea medication, or pain relief. Generally, follow up appointments are not required.
- Surgical – During hospitalisation, intravenous fluid therapy will be continuous to restore fluid loss before and during the surgery (due to continuous vomiting and anorexia) and to maintain a stable hydration. Pain relief, antibiotics, antacid and prokinetics (help the intestines to resume functional motility) may be given.
If you have concerns for your pet in connection to this condition we recommend discussing it with your primary care vet in the first instance, or get in touch with our team for more info.
If you need urgent medical help, contact our 24 hour Pet Emergency team at Stafford, North Lakes, or Sunshine Coast on 1300 QLD VET (1300 753 838)