Dog food safety: what dogs can and can't eat

These are the items behind most emergency calls. For each one, what matters is not only that it is toxic but how the dose works — that is what tells you whether you have a problem or an emergency.

Chocolate, cocoa and caffeine

The toxin is theobromine, and dogs clear it roughly ten times more slowly than people do. Concentration is what matters: baking chocolate and cocoa powder carry several times the theobromine of milk chocolate, so a small piece of a dark bar outweighs a large piece of a milk one. Expect vomiting and restlessness first, then a racing heart, tremors and, at high doses, seizures. Coffee, espresso grounds and caffeine tablets act the same way.

Chocolate · Coffee

Grapes, raisins, sultanas and currants

There is no established safe dose. The mechanism is still debated, with tartaric acid the current leading candidate, and sensitivity varies enormously between individual dogs — the same handful that does nothing to one dog can put another into acute kidney failure within 24 to 72 hours. Treat any amount, fresh or dried, as an emergency. Dried fruit is the bigger risk because it is concentrated and hides in flapjacks, scones, cereal bars and trail mix.

Grapes

Xylitol, also sold as birch sugar

Xylitol makes a dog's pancreas dump insulin, and blood sugar can crash inside 30 minutes; larger doses cause liver failure a day or two later. Roughly 0.1 g per kg of body weight is enough to trigger hypoglycaemia, which a single piece of sugar-free gum can exceed for a small dog. Check labels on sugar-free gum and mints, peanut butter, protein bars, children's medicines and anything marked no added sugar.

Xylitol

Onions, garlic, leeks, chives and shallots

These damage red blood cells and cause haemolytic anaemia. Two things make them deceptive: the damage is cumulative, so repeated small servings add up over days, and cooking, drying and powdering do not reduce toxicity. Onion and garlic powder are the usual culprits, hidden in stock cubes, gravy, curry paste, pizza and some baby foods. The signs — pale gums, lethargy, dark urine — often appear only after several days.

Onions · Garlic

Macadamia nuts

As little as 2 g per kg produces weakness, hind-leg tremors, vomiting and a raised temperature, usually within 12 hours. The mechanism is still unknown. It is rarely fatal and most dogs recover within 48 hours, but it looks alarming and warrants a call to the vet — especially if the nuts came coated in chocolate, which turns one problem into two.

Macadamia Nuts

Alcohol and raw yeast dough

Dogs are far more sensitive to ethanol than people, and raw dough is the worst form of it: the stomach works as a warm proving drawer, so the dough keeps rising and fermenting, producing alcohol while it expands. That combines poisoning with a risk of painful bloat or gastric torsion. Beer, wine, spirits, liqueur-filled desserts and unbaked bread dough all belong in the same category.

Alcohol · Raw Yeast Dough

Human painkillers and medicines

Never give a dog paracetamol, ibuprofen, naproxen or aspirin from your own cupboard. Human anti-inflammatories cause stomach ulceration and kidney damage at doses that look small, and the margin between a helpful and a harmful amount is far narrower than it is in people. If your dog is in pain, both the drug and the dose have to come from a vet.

Ibuprofen · Naproxen · Acetaminophen

Cooked bones, corn cobs and stone fruit pits

These are mechanical hazards rather than poisons, and they send more dogs into surgery than most toxins do. Cooked bones dry out and splinter into sharp fragments. Corn cobs are the classic small-intestine obstruction because they never break down. Peach, plum, apricot and cherry stones can both block the gut and, if the kernel is crushed, release cyanogenic compounds.

Cooked Bones

Plenty of everyday food is fine for a dog. The pattern is consistent: plain, cooked, unseasoned, and small.

Plain cooked meat, fish and eggs

Chicken, turkey, lean beef, white fish and cooked eggs make excellent treats. The rule is plain — no salt, oil, butter, marinade, onion or garlic, and no bones. Remove skin and visible fat, which is the usual trigger for pancreatitis after a rich meal.

Vegetables

Carrot, green beans, cucumber, courgette, plain pumpkin and small florets of broccoli are all fine raw or steamed. Cut them to a size your dog cannot inhale whole; carrot batons are a common choking hazard for enthusiastic eaters. Plain pumpkin puree is also the standard suggestion for a mildly unsettled gut.

Fruit

Apple without the core and pips, blueberries, banana, strawberries, seedless watermelon flesh and peeled pear are safe in small amounts. They are also sugary, so they count as treats rather than food. Remove pips, stones and cores every time.

Grains and starch

Plain cooked rice, oats, pasta and well-cooked potato or sweet potato are easy on the stomach and are what most vets suggest for a bland recovery diet. Everything must be cooked — raw potato contains solanine — and served without butter, salt or sauce.

Dairy, in small amounts

Plain yoghurt, kefir and a little hard cheese suit some dogs and not others: most adult dogs produce little lactase, so milk in any quantity often means diarrhoea. Cheese is fatty and salty as well. It works better as a way to hide a tablet than as a snack.

Two rules cover almost everything: treats of any kind should stay under about 10% of daily calories, and new foods should go in one at a time, in small amounts, with two or three days in between so you can tell what caused a reaction.

No list covers everything, and the useful skill is knowing what question to ask. These five cover most real situations.

Dose and body weight decide almost everything

Toxicity is not a property of a food, it is a property of the amount relative to the animal. One raisin is a materially different event for a 3 kg Chihuahua and a 40 kg Labrador. When you look something up, look up the dose, not just whether the food appears on a list of bad things.

The seasoning is usually the problem, not the ingredient

Plain roast chicken is a good treat; the same chicken from a rotisserie is coated in salt, garlic and onion powder. Most calls that begin with my dog ate some of my dinner turn out to be about what the food was cooked with rather than the food itself.

Look for a hidden sweetener before anything else

If the item is sugar-free, diet, no added sugar, or a supplement, check the label for xylitol or birch sugar before you do anything else. It is the one common household ingredient that is genuinely dangerous in tiny amounts.

Treat pits, stones, cores and bones as a separate question

A food can be perfectly safe while the hard part inside it is not. Ask two questions rather than one: is the flesh toxic, and can the stone, core or bone obstruct the gut or splinter.

Fat is its own hazard

A large amount of fat — trimmings, drippings, a stolen block of butter — can trigger pancreatitis, which has nothing to do with poisoning and is a serious illness in its own right. Rich leftovers are why vets are busy after every holiday.

The useful window is the first hour. Do not wait to see whether symptoms develop: with grapes, xylitol and antifreeze the damage is well under way before a dog looks unwell.

Do this first

• Take the rest away and move your dog somewhere you can watch them.
• Work out what, how much and when. A rough weight or a count is far better than nothing.
• Keep the packaging, the label, or a photo of the plant — the ingredient list often changes the treatment.
• Call your vet, the out-of-hours service or a poison hotline straight away, and give your dog's weight.
• Follow the advice you are given, and go in if you are told to, even if your dog seems fine.

Do not do this

• Do not induce vomiting unless a professional has told you to. It is the wrong move for corrosives, petroleum products and sharp objects, and it risks aspiration.
• Do not use salt, mustard or hydrogen peroxide to make your dog sick. Salt causes poisoning of its own.
• Do not give milk, oil or anything to line the stomach; some toxins are absorbed faster in the presence of fat.
• Do not give any human medicine, and do not repeat a dose of a prescription your dog has already had.
• Do not wait for symptoms in order to confirm your suspicion.

Signs that mean go now

• Repeated vomiting or diarrhoea, especially with blood
• Drooling, pawing at the mouth, or difficulty swallowing
• Tremors, twitching, unsteadiness or collapse
• Seizures — go immediately
• Rapid or laboured breathing, or a racing heart
• Pale, white or yellow gums
• A swollen, hard or painful abdomen, or retching that brings nothing up
• Sudden lethargy, hiding, or refusing food for more than 24 hours