Gastrointestinal obstructions caused by foreign bodies
Swallowing a foreign body (FB) is more common in young animals than in older ones. Dogs — some breeds more than others (Labradors, Golden Retrievers and so on) — and ferrets are the species most inclined to swallow things that are not food. But any animal can accidentally swallow a troublesome FB. As for the why, it is hard to say: habit, an appealing smell or texture? Some rodents with dental disease, for instance, do at times swallow fragments of objects.
Besides inedible FBs (toys, most of the time), there are trichobezoars (hairballs) and oversized pieces of otherwise edible food that can cause trouble. Each species has its own speciality: cats with their hairballs — or with balls, string and fish hooks; cows with apples and nails; dogs and ferrets with anything and everything; rodents with paper; and so on.
Reptiles, largely protected inside their terrarium, tend to escape this kind of trouble. Their skill at detecting prey also keeps them from making mistakes.
Tortoises and horses, too, seem to sort through their surroundings more carefully than other animals! In dogs and ferrets, we sometimes retrieve very unusual finds: nylon stockings, a conker, a purse (banknotes digest faster than leather…), an umbrella sleeve, buttons, pine cones, pieces of furniture and more. The literature even records swallowed mobile phones and Walkmans! In short, the operation often feels rather like opening a Kinder Surprise!
An FB can follow several courses. Either it travels the whole way through and comes out in the stools after a while, or it can get stuck: in the oesophagus (rare), in the stomach (frequent), in the loops of the small intestine (occasionally) or at the junction with the caecum (often), or in the colon (rare). It lodges by preference at the natural narrow points of the gastrointestinal tract.
The symptoms are fairly typical: vomiting, straight after eating or slightly delayed depending on where the blockage sits, smelling worse and worse; droppings that stop, usually completely; discomfort when the abdomen is felt; a generally unwell animal. A blockage can cause very acute signs, but sometimes a degree of chronicity sets in before the symptoms point clearly enough to the problem.
Together with the history and the clinical picture, further tests — generally X-rays, with or without contrast — complete the diagnosis. Either the FB itself is visible, or the image shows the tell-tale signs of a blockage.
Once an obstruction is diagnosed, the best treatment is surgery. Conservative treatment is only possible for a mild, incomplete obstruction, which is the rarer case.
An opening is made into the target organ: a gastrotomy for the stomach, an enterotomy of the duodenum, jejunum or ileum, possibly a typhlotomy (caecum) or — more rarely needed — a colotomy. The FB can sometimes cause necrosis of the overstretched tissue, in which case part of the organ is removed to prevent toxaemia. It is sometimes necessary to anchor some of these organs in place before the wound is closed.
The post-operative phase is delicate for the 48 h after surgery: food is reintroduced gradually, fluids given gently, the vital parameters monitored and appropriate antibiotics provided, alongside the other usual measures.
The outlook is usually good, unless the necrosis is too extensive or difficult to remove — the hardest part is avoiding a repeat performance!