Ingesting obsession - the secret life of canines who just can't say no

FOREIGN AFFAIR: Eating strange items may indicate a behavioural issue. Picture: Shutterstock
FOREIGN AFFAIR: Eating strange items may indicate a behavioural issue. Picture: Shutterstock

Intestinal foreign bodies are a common cause of life-threatening illness in dogs.

Worse still, a number of dogs I treat for intestinal foreign bodies are serial offenders.

A paper published in the Journal of Veterinary Behaviour (Masson et al., 2021) suggests that this may be because pica (the ingestion of non-food items like fabrics, plastics, rubber, stone, metal or wood) can be a sign of an underlying behavioural disorder.

The researchers noted that pica also occurs in humans and may have links to some psychiatric conditions, and therefore they explore if there may be similar issues contributing to the behaviour in dogs.

The study looked for evidence of potential behavioural causes in dogs requiring removal of foreign bodies.

Intestinal foreign bodies are a problem because they can cause obstruction of the gastrointestinal tract, preventing food from passing through.

They cause pain, nausea and vomiting.

They are associated with dangerous loss of body fluids, and damage to and even perforation of the gut wall, especially if they are sharp or linear.

Diagnosis may be challenging.

Treatment usually requires removal of the foreign body, either via endoscopy or surgery, and repair of secondary damage to the gut.

Some dogs require multiple surgeries and prolonged time in hospital. In this study, five per cent of the dogs that underwent surgery for foreign body removal by a specialist, died, in spite of all attempts to help them.

That's a mortality rate of 1 in 20.

In selecting dogs for the study, the researchers excluded puppies under the age of six months, when accidental ingestion of non-food items is common.

They also excluded dogs that had ingested materials such as stone fruit pits or fishhooks, as these may occur when dogs are simply trying to eat what may be covered in, and what smells and tastes to them like food.

This doesn't point to a behaviour disorder, but it does remind us to be very careful when disposing of "rubbish" that may be tempting for a dog to eat.

To me one of the most interesting findings in this study was the number of foreign bodies found inside the affected dogs.

Most (52 per cent) had eaten between one and five objects; 19 per cent ate between six and ten objects; 24 per cent ate between 11 and 50 objects and five per cent ate over 50 objects.

How can a dog eat more than 50 objects?

Usually, such items are small.

I have seen dogs swallow small pebbles or hair ties which, in isolation, may not cause any dramas. But en masse, they are too much for the digestive system.

What we don't know, and what can be very hard to tell as a veterinarian retrieving these objects surgically, is over what time period they were eaten.

But there's a good chance that, for at least some of these dogs, pica was a habit.

Which brings me back to behaviour.

The researchers found evidence of a behavioural disorder in 88 per cent of the dogs with foreign bodies.

Behavioural disorders included hyperactivity, impulsivity, obsessive-compulsive disorders, anxiety and attachment-related troubles.

Dogs that shredded the objects they eventually ingested were more likely to have a hyperactivity-impulsivity disorder.

What does this mean for dogs who eat foreign bodies?

If we don't attend to the underlying behavioural disorder, it may happen again.

If your dog repeatedly eats non-food items, talk to your veterinarian about referral to a behaviour vet.

When it comes to foreign bodies, prevention is much better for your dog than cure.


MASSON, S., GUITAUT, N., MEDAM, T. & BÉATA, C. 2021. Link between Foreign Body Ingestion and Behavioural Disorder in Dogs. Journal of Veterinary Behavior, 45, 25-32.

Dr Anne Quain BVSc (Hons), MANZCVS (Animal Welfare), Dip ECAWBM (AWSEL) is a lecturer at the Sydney School of Veterinary Science and a practising veterinarian.