Why do dogs and cats eat dangerous things?

Why do dogs and cats eat dangerous things?

Dr Jacqui Ley

BVSc(Hons) PhD DiplECAWBM FANZCVS(Veterinary Behaviour)
Registered Specialist in Veterinary Behavioural Medicine
Consulting at the Melbourne Veterinary Specialist Centre

We are often surprised by the strange things that dogs and cats chew on and sometimes swallow. These dietary indiscretions can have serious consequences for our pets so understanding what may cause them to eat dangerous foods, plants or non-food items can help keep your pet safe.

So why do they eat things they shouldn’t?

Dogs are a scavenging hunting species that eats a wide range of foods. They can be described as a meat-biased omnivore.  To a dog if something is organic then it is possibly food. As a scavenging species, they evolved to find food where they can and to be prepared to work to get to it.

Dogs did not evolve in an environment where there was lots of food, easily available and that they could store and ration. Dogs tended to gorge if there was food available. Unlike humans, dogs have not evolved higher level reasoning to understand that food can be saved for later and they do not have to eat everything in one go. This is why when dogs get into food storage (bulk dog food, the pantry) they generally gorge themselves. For many dogs this can be dangerous and lead to gastro-intestinal accidents.

Some food are dangerous for dogs to have (chocolate, grapes, onions) but they do not understand this and again if given the opportunity they gorge themselves, sometimes with fatal consequences. Dogs will also eat rotten foods or the compost and may pick up bacteria that causes vomiting and diarrhoea.

Dogs do not have ethics or morals so do not think of anyone else’s feelings or needs. They look out for number one and this means that if they can get into your chocolate stash, they will. Getting cross at them won’t protect them; being a savvy owner will.

Protect your dog from its own nature. Keep food stored properly and prevent unattended access. If your household is busy, use self-closing doors or locks to help prevent accidental access. Supervise children when eating. Be aware of your dog and food at holidays and celebrations when humans tend to eat food dangerous for dogs (e.g., Easter eggs, Christmas cake). Dispose of food scraps safely and securely. Keep your compost heap covered and restrict your dog’s access to it.

Anything soaked in organic materials can be seen as edible by dogs (e.g., used tissues, used sanitary products, used nappies). It is gross to us, but dogs are scavengers and these items have digestible material on them. These products can all cause blockages. Ensuring pet proof disposal of the items is the best way to prevent problems.

Cats are not immune from making poor dietary choices too. They are obligate carnivores – they must eat meat – and evolved to work hard to get their food. They also did not evolve in an environment that was full of easy to get food; the modern human house is very different from the ancestral home of cats. Some cats will gorge on cat food if they get the chance. They may also learn about human food and may steal or try and eat as much as they can if they find food unattended. Some cats also learn to raid the rubbish bin.

Common food related emergencies with cats involve fish or chicken bones lodging in the cat’s mouth and/or oesophagus. Or getting their head stuck in containers that held food. Storage for food with a hungry cat may need to be even cleverer than for dogs. In some households, toddler locks are needed to keep the cat out of cupboards. Empty the trash frequently if you have a pet that raids the rubbish bin.

Cats also like to eat greenery and many chew on grasses or eat vegetables. If they are confined cats, they may chew on whatever they can find. Avoid plants that are not safe for cats; lilies are particularly poisonous. Provide your cat with opportunities to eat safe grasses and greenery.

So why do pets eat medications, food that are dangerous for them, poisons, and other really dangerous stuff?

Many of these items are meant to be eaten and digested, just not by dogs and cats. Our pets are unable to understand this. If something smells like food, then it must be food and some pets are willing to eat it. Some pets will work very hard to access items.

Humans like foods that are dangerous for our pets and often like to eat them in large amounts. Dogs would be unlikely to find and eat a whole lot of raw onions in the wild, but onion soup, onion pie, salads with raw onion chopped finely are all things that might be on a human’s menu and accessible to pet dogs. The dangerous part is mixed with safe foods and it all smells good.

The same goes for medications. To make them easy for people to take, the medication may be mixed with digestible binders or solutions. It all smells like food and some dogs will fossick out food where they can smell it.

Poisons for vermin such as mice or snails have a digestible base; it is designed to be eaten to kill the target animal.

Some non-food products can smell like edible items; anti-freeze smells and tastes sweet and some animals will drink it unless it altered to make it unpleasant.

Cats may also ingest poisonous items. One particular culprit are household plants and flowers. Many cats like to chew on greenery.

Keeping your pets safe involves being aware of how they are different from humans in what is safe for them to eat and that they cannot understand that some things that smell and taste delicious may hurt them. Making sure that they cannot access these items is the only reliable way to keep them safe.

Puppies and Kittens

Baby animals need their own consideration when it comes to accidental poisonings. Everything is new for puppies and kittens. One of the ways they learn about their new environment is to chew on things. They are not naughty – just exploratory. Providing supervision, safe toys and putting unsafe items in pet proof protection (i.e. cupboards) will help keep new pets safe.

Puppies and kittens grow up quickly and learn new tricks. It is easy to not realise that they can access areas that previously they could not. People with a new puppy or kitten may be caught out if they are not constantly checking that there is nothing their pet can access.

Emotional Ingestion

This behaviour is often baffling to owners. Some pets will chew and swallow non-food items. These may be the owner’s possessions, rocks, fabric or found items. Sometimes the items pass safely through the pet. Sometimes, serious blockages or problems may develop. There are several reasons why a pet may ingest non-food items.

Sometimes items are chewed up and swallowed in play. Remember dogs evolved to chew and break things to get to food. Check that toys are not broken and being ingested. Pets will play with what they can find this can include rocks, stone fruit, sticks, seed pods, medications in a container or blister pack, etc. Provide a safe place and suitable playthings.

Some dogs learn that humans will grab things the dog has found (socks, jocks, stones) and take them! The dog learns to swallow the items really quickly. Keeping items away from the dog, being low key if the dog has something and offering a better food treat to make the dog release the item can all help prevent a gastrointestinal accident.

Some animals suffer from a mental health condition called Pica. The affected individual has an overwhelming desire to eat non-food items. The condition is well described in cats. These animals may chew up fabric or ingest small toys or other items. Many have had multiple surgeries to relieve blockages. These pets need a very clean and safe environment and may need medications to help relieve the desire to ingest the items. Distraction with appropriate toys and food dispensing toys can help distract them from the behaviour. In dogs and cats, the condition is not associated with any dietary imbalances.

Distress caused by separation of the pet from the owner can also be a cause of chewing or eating non-food items. Frustratingly the pet often chews up items bellowing to the owner. Assessment and treatment by a veterinary psychiatrist, veterinarian with an interest in behaviour is necessary to help treat this condition.

Accidental poisonings and gastrointestinal blockages are largely preventable. Recognising that our pets are not capable of understanding what foods and items are dangerous for them, preventing access and providing safe and suitable food toys can all help prevent accidents. In some cases, especially of repeated behaviour, the pet may need assessment for a mental health condition by a suitably qualified veterinarian.