What is it?
Dogs are great scavengers - and this means that they periodically gobble up things that they shouldn’t! Unlike having a touch of constipation, however, having a foreign object blocking their bowel is a life-threatening emergency.
Why is it important?
Dogs eat random things because they are evolved not just to be predators, but scavengers as well. Now normally, the dog relies on being able to vomit anything nasty back up again. However, sometimes they eat something that’s exactly the wrong size or shape, which becomes lodged somewhere in their intestines. This is known as an “ingested foreign body”, and the blockage causes a number of harmful effects.
Firstly, if food and fluid can’t get past the blockage, the dog will develop severe vomiting, which can lead to dehydration, shock and collapse. Secondly, the gut will try to push it onwards - but if it won’t move this results in damage to the gut wall, potentially allowing bacteria to penetrate the bloodstream, leading to septicaemia. Finally, as the intestine is stretched by the obstruction, it will often find its blood supply compromised or cut off, resulting in death and necrosis (gangrene) of the bowel.
What's the risk?
All dogs who eat things they shouldn’t (which is pretty (much any type of dog!). However, the more greedy the dog, the higher the risk - which is why Labradors and Retrievers are particularly prone to obstructions.
Similarly, older dogs are less likely to be stupid about what they stick down their throats, so puppies and young adults are at an increased risk too.
What happens to the pet?
The most common symptom is profuse, often violent vomiting. However, it is a myth that only dogs with projectile vomiting have a foreign body - any dog who’s constantly throwing up may have one. One of the warning signs to be aware of is that in most cases, dogs with an obstruction are unable to even keep water down. This may lead to dehydration (dry gums, fast heart rate, collapse), kidney failure and even death. Other symptoms include abdominal pain; failure to pass any droppings; and toxic shock. Toxic shock usually presents with a fast, weak pulse, weakness and lethargy, and bright red or purple gums. Dogs with these symptoms are critically ill and need emergency treatment right away.
How do you know what's going on?
A dog with severe vomiting or any of the other symptoms listed needs to be seen by our vets straight away. Most of the time, of course, they’ve just got a severe stomach upset - but we will always try to determine whether there’s anything more sinister going on! In some cases, the presence of a foreign body is known (perhaps because the owner saw the dog eat it), but usually, we’ll have to look for it. Depending on what it is, we may see the object on X-rays (bone, stone and metal show up really well, but not plastic, rubber, wood etc), or an ultrasound scan, but sometimes we will need to do an exploratory laparotomy (“ex lap”). This involves us giving a general anaesthetic, opening your dog up and looking at their guts to try and find the problem.
What can be done?
The only treatment is surgery to remove the obstruction, and cut out any dead or dying bowel. Some dogs are too sick for surgery right away, so these patients need to go onto intensive care nursing with intravenous fluids etc.
How can I protect my pet?
Prevention is very easy, in principle - make sure your dog doesn’t have unsupervised access to anything he might eat that isn’t food! In practice, this can be harder than it sounds… Some dogs even need to have a basket muzzle on whenever they’re out and about, or in the garden. If your dog is this way inclined, talk to one of our vets for advice!