Can Dogs Eat Garlic?

Garlic has a reputation as a health food, and some owners deliberately add it to their dog’s bowl to ward off fleas or boost immunity. Unfortunately, for dogs garlic is a toxin, not a tonic. It belongs to the same plant family as onion and causes the same kind of damage to red blood cells, and it is considerably stronger.

This guide explains why garlic is harmful, how much is dangerous, the myths worth ignoring, and what to do if your dog has eaten some.

Why garlic is toxic to dogs

Garlic is a member of the Allium family, along with onions, leeks, chives and shallots. These plants contain sulfur compounds that cause oxidative damage to red blood cells once absorbed. The damaged cells become fragile and are broken down early, which can lead to hemolytic anemia: too few healthy red blood cells to carry oxygen.

The Merck Veterinary Manual describes garlic as three to five times more toxic than onion. Raw, cooked, roasted, dried, powdered and supplement forms are all a risk, and cooking does not make it safe.

How much garlic is dangerous?

There is no precise, well-established toxic dose of garlic for dogs, and sensitivity varies between individuals. What we do know:

• Clinical signs have been reported in dogs after 15 to 30 grams of raw onion per kilogram of body weight.
• Garlic is three to five times more potent than onion.

Putting those together gives a rough sense of scale (an estimate, not a safe limit) of around 3 to 10 grams of garlic per kilogram of body weight. For a 20 lb (9 kg) dog that is roughly 27 to 90 grams, or something like five to eighteen average cloves. For a 10 lb dog it is roughly half that.

Two things make real-world exposures more dangerous than these numbers suggest:

• Concentrated forms. Garlic powder, granules, dried garlic and garlic supplement tablets contain far more garlic per gram than fresh cloves. A few teaspoons of powder can be a significant dose for a small dog.
• Repeated feeding. Small amounts given every day (in table scraps, homemade food or “natural” supplements) can add up to cause anemia over time.

Myths about garlic and dogs

“Garlic keeps fleas away.” There is no reliable evidence that feeding garlic repels fleas or ticks, and the doses some owners use are enough to damage red blood cells. Effective, safe flea and tick prevention is available from your vet.

“A little garlic boosts the immune system.” Health claims for garlic in dogs are not backed by good evidence, while its effect on the blood is well documented.

“It’s fine because it’s in some dog treats.” A few products contain small amounts of garlic as a flavouring. Their presence on a shelf is not evidence of safety, and many vets advise avoiding them.

Where garlic hides

Fresh cloves are easy to spot. Garlic in prepared food is not. Check labels and recipes for garlic, garlic powder, garlic salt, dried or granulated garlic and “Allium sativum”, and be careful with:

• pasta sauces, curries, stir-fries and soups
• pizza, garlic bread and garlic butter
• stock cubes, bouillon and gravy granules
• sausages, burgers, meatballs, marinated and seasoned meats
• hummus, dips and dressings
• seasoning blends and some savoury snacks
• “natural” supplements and a few treats sold for dogs

If you cook for your dog, leave garlic and onion out of their portion entirely: plain, unseasoned food is safest.

Safer alternatives

If you were giving garlic for fleas or ticks, ask your vet about licensed parasite prevention. These products are tested for safety and actually work. If you were using it to make food more appealing, plain cooked chicken, a little warm water on dry food or a vet-recommended food topper are safe ways to tempt a fussy eater.

Signs of garlic poisoning in dogs

Within the first day, some dogs have vomiting, diarrhea, drooling or belly discomfort, and garlic breath. Many show nothing at first.

Over the next three to five days or so, as red blood cells are destroyed, watch for:

• lethargy, weakness and tiring easily on walks
• pale, white or yellow-tinged gums
• fast breathing and a fast heart rate at rest
• red, brown or dark urine
• reduced appetite
• collapse in severe cases

What to do if your dog ate garlic

1. Take away anything left and note what it was: fresh cloves, a garlicky dish, garlic bread, powder or supplements, and roughly how much.
2. Note your dog’s weight.
3. Call your vet or a pet poison line. In the US, the ASPCA Animal Poison Control Center is on 888-426-4435 and the Pet Poison Helpline on 855-764-7661. Both charge a fee.
4. Do not induce vomiting unless a vet tells you to and explains how.
5. Check your dog’s gums and urine daily for about a week, even if your dog seems normal.

If you have been feeding garlic regularly

Some owners only discover that garlic is harmful after giving it for weeks or months, often as a flea remedy or supplement. If that is you, there is no need to panic, but do stop feeding it and mention it to your vet. A simple blood test can show whether your dog’s red blood cells have been affected, and dogs with mild changes usually recover once the garlic is removed from their diet. Book a check sooner if your dog seems tired, has pale gums or dark urine.

How vets treat garlic poisoning

Treatment is the same as for onion poisoning. If the garlic was eaten recently, the vet may induce vomiting and give activated charcoal. They will then monitor red blood cell counts with blood tests over several days. Supportive care with fluids and rest is often all that is needed. Dogs with severe anemia may need oxygen or a blood transfusion. Most dogs recover as new red blood cells are made.

Related foods

Onions carry the same risk at a somewhat larger dose. See can dogs eat onions. Leeks, chives and shallots are in the same family. For other dangerous foods, including chocolate and grapes and raisins, see our poisoning and emergencies section.