What to Put in a KONG: Fillings That Actually Last

A KONG is a hollow rubber toy you fill with food. The dog has to work the food out, which turns a two-minute meal into twenty or thirty minutes of chewing and licking. That is the whole idea, and it is why a KONG gets recommended so often for dogs left alone, dogs on box rest, and dogs who are simply bored.

The difficulty is that most people underfill it. A few biscuits rattle out in ninety seconds and the dog looks at you as if to say, is that it. Below is how to pack one so it actually lasts.

The method: layer it, don't just fill it

The trick is to make the easy bit easy and the last bit hard.

1. Plug the small hole at the narrow end with something sticky — a smear of peanut butter or a little cream cheese. This stops everything falling straight out.
2. Pack the middle with your dog's normal dry food, mixed with something wet to bind it.
3. Seal the wide end with a second sticky layer, then press one really good thing right at the opening so the dog gets an immediate reward and keeps going.

That last point matters more than people expect. If the first thirty seconds are boring, plenty of dogs give up and walk off.

Fillings you probably already have

• Your dog's own kibble, soaked in a little warm water so it swells and sticks together
• Wet dog food, which binds everything and freezes well
• Plain natural yoghurt
• Mashed banana
• Cooked carrot or sweet potato, mashed
• Peanut butter — check the label first, see the warning below
• Plain cooked chicken, shredded

If you would rather use something made for the job, KONG Easy Treat is a spray paste that goes straight into the cavity and reaches the bits a spoon cannot. It comes in peanut butter, cheddar cheese, liver, and a puppy version. KONG Snacks are shaped biscuits designed to wedge in the opening, which is exactly the job described in step three.

What to keep out

Some everyday foods are genuinely dangerous to dogs. Do not use:

• Anything containing xylitol — check peanut butter labels carefully, as some sugar-free brands contain it
• Grapes, raisins, sultanas
• Onion, garlic, leek
• Chocolate
• Cooked bones of any kind

If your dog has a known allergy, a sensitive stomach, or is on a prescription diet, stick to their own food as the filling and speak to your vet before adding anything new.

Freeze it

This is the single biggest difference between a KONG that lasts ten minutes and one that lasts an hour. Fill it, stand it upright in a mug so nothing leaks, and freeze it overnight.

Frozen fillings take far longer to work out, and the cold is soothing for teething puppies. It is also worth making several at once — a row of them in the freezer means you always have one ready for the days you need to leave the house in a hurry.

Which KONG, and which size

There are three rubber formulas, and they are not interchangeable.

• KONG Classic — the original red rubber, for average chewers. Six sizes from X-Small to XX-Large.
• KONG Extreme — black rubber, the toughest formula, for dogs who destroy everything else. Five sizes from Small to XX-Large.
• KONG Puppy — softer rubber for milk teeth, in four sizes.

On sizing, go by your dog's chewing strength as much as their weight. A determined 15kg terrier may well need a bigger, tougher KONG than a gentle 30kg retriever. If you are between sizes, size up: a KONG that is too small is a choking risk, and a bigger one simply holds more food.

Replace any rubber toy once it is chewed through or has pieces missing.

Keeping it clean

A stuffed KONG needs washing, particularly if you have used dairy or meat. They are dishwasher safe on the top rack, or a bottle brush and hot soapy water does the job. Having two or three in rotation is easier than washing one every day.

A note on how much

Whatever goes in the KONG is food, not an extra. Take it out of your dog's daily allowance rather than adding it on top, or you will be quietly overfeeding. If you are unsure how much that should be for your dog, your vet is the right person to ask.

You can see the full KONG range at UK9 Petcare, including every Classic, Extreme and Puppy size, the Easy Treat pastes and KONG Snacks.