Can Dogs Eat Liquorice? Safety Guide for Black, Red & Root

If your dog snatched a piece of liquorice off the coffee table, you're probably wondering whether to panic or just monitor. The answer depends entirely on which type of liquorice you're dealing with — and the distinction matters more than most pet owners realize.

Why Black Liquorice Is Dangerous for Dogs

The primary concern with black liquorice is glycyrrhizin (also called glycyrrhizic acid), a compound extracted from the root of the Glycyrrhiza glabra plant. Glycyrrhizin is what gives black liquorice its distinctive flavor — and it's also what makes it potentially toxic to dogs.

Glycyrrhizin mimics the hormone aldosterone in the body, triggering a cascade that causes the kidneys to excrete potassium while retaining sodium. This condition, known as pseudohyperaldosteronism, can lead to:

• Hypokalemia (dangerously low potassium levels) — causing muscle weakness, tremors, and in severe cases, cardiac arrhythmias
• Hypertension (elevated blood pressure) — stressing the cardiovascular system
• Fluid retention and edema — particularly dangerous for dogs with pre-existing heart or kidney conditions
• Metabolic alkalosis — disrupting the body's acid-base balance

According to the ASPCA Animal Poison Control, even moderate amounts of glycyrrhizin can produce clinical signs in sensitive dogs. The Merck Veterinary Manual notes that glycyrrhizin toxicity thresholds vary by individual, meaning there is no universally "safe" dose for home administration.

Toxic dose context: In human medicine, chronic ingestion of as little as 100 mg of glycyrrhizin per day has been linked to adverse effects. Dogs, particularly small breeds, have far lower thresholds. A single ounce (28 g) of black liquorice candy can contain between 6–20 mg of glycyrrhizin depending on the brand and formulation — enough to cause concern in a toy-breed dog.

What About Red Liquorice?

Here's where many dog owners get confused. Despite the name, red liquorice (like Twizzlers or Red Vines) typically contains no actual liquorice root extract. The flavor comes from artificial or natural fruit flavoring, and the primary ingredients are sugar, corn syrup, wheat flour, and food coloring.

This means red liquorice won't cause glycyrrhizin toxicity. However, that doesn't make it a good treat choice:

• High sugar content: A standard Twizzler twist (about 9 g) contains roughly 5 g of sugar. For a 20 lb dog, that's proportionally similar to a human eating a full candy bar.
• Artificial additives: Red 40, blue 1, and other food colorings have no place in a dog's diet and may trigger sensitivities in some animals.
• Choking and obstruction risk: The chewy, rope-like texture can pose a choking hazard for small dogs or aggressive chewers who don't break food into smaller pieces.
• Wheat/gluten content: Dogs with grain sensitivities or wheat allergies may experience digestive upset.
• Xylotine risk (sugar-free varieties): Some sugar-free liquorice products use xylitol, an artificial sweetener that is extremely toxic to dogs, causing rapid hypoglycemia and liver failure. Always check ingredient labels.

Liquorice Root Supplements: Why DIY Is Risky

You may encounter liquorice root (Glycyrrhiza glabra) marketed as a herbal supplement for dogs, sometimes touted for its anti-inflammatory or digestive-soothing properties. It's true that some veterinary herbalists incorporate deglycyrrhizinated liquorice (DGL) — a form with the glycyrrhizin removed — into treatment protocols for conditions like gastric ulcers or inflammatory bowel disease.

However, there are critical distinctions:

The takeaway: Never administer liquorice root supplements to your dog without direct veterinary supervision. If your vet recommends DGL as part of a treatment plan, follow their dosing instructions precisely and attend all follow-up blood work appointments.

What Happens If My Dog Eats Too Much Liquorice?

The severity of a reaction depends on the type of liquorice ingested, the quantity, and your dog's size and health status. Here's a symptom timeline to watch for:

Within 1–4 Hours (Acute Phase)

• Vomiting or regurgitation
• Diarrhea (especially with red liquorice due to sugar load)
• Excessive drooling or lip-licking (nausea indicator)
• Restlessness or pacing

Within 4–24 Hours (Systemic Effects — Black Liquorice)

• Muscle weakness or reluctance to move
• Tremors or twitching (signs of hypokalemia)
• Increased thirst and urination (polydipsia/polyuria)
• Elevated heart rate or irregular heartbeat
• Lethargy or collapse in severe cases

With Xylitol-Containing Products (Emergency — Any Timeframe)

• Vomiting within 15–30 minutes
• Rapid drop in blood sugar causing weakness, disorientation, seizures
• Jaundice (yellowing of gums/eyes) indicating liver damage — may appear 12–72 hours post-ingestion

Dogs Who Should Never Eat Liquorice in Any Form

Even a small amount of liquorice — including red liquorice candy — should be avoided entirely for dogs in these categories:

• Dogs with heart disease: Glycyrrhizin-induced sodium retention and potassium loss can worsen congestive heart failure and arrhythmias. Breeds predisposed to dilated cardiomyopathy (DCM) — including Doberman Pinschers, Great Danes, and Cocker Spaniels — are at elevated risk.
• Dogs with kidney disease: Compromised kidneys struggle to regulate electrolytes; adding glycyrrhizin to the mix can trigger dangerous imbalances.
• Dogs with liver disease: The liver metabolizes glycyrrhizin; impaired liver function increases toxicity risk.
• Senior dogs (generally 7+ years): Older dogs are more likely to have undiagnosed organ dysfunction and are less resilient to metabolic disruptions.
• Puppies under 12 months: Their developing systems and smaller body mass make them far more susceptible to toxicity at lower doses.
• Dogs on certain medications: Liquorice root interacts dangerously with NSAIDs (like Rimadyl/carprofen), corticosteroids (prednisone), diuretics (furosemide), and cardiac glycosides (digoxin). If your dog is on any prescription medication, assume liquorice is contraindicated unless your vet says otherwise.
• Diabetic dogs: The sugar content in liquorice candy can cause dangerous blood glucose spikes.

Similar Foods and Products to Avoid

If you're checking your pantry for dog-safe treats, keep these liquorice-adjacent items away from your dog as well:

Healthier Treat Alternatives Your Dog Will Actually Love

Rather than risking liquorice exposure, offer treats that deliver real nutritional value and are proven safe. Here are veterinarian-recommended alternatives ranked by nutritional benefit:

• Blueberries: Rich in antioxidants (anthocyanins), vitamin C, and fiber. Safe serving: 2–3 berries for small dogs, 5–8 for large dogs. Low in sugar at approximately 10 g per cup.
• Carrots (raw or steamed): High in beta-carotene and fiber, excellent for dental health when given raw. A baby carrot or two is a perfect low-calorie treat (about 4 calories each).
• Apple slices (no seeds or core): Provide vitamins A and C and pectin fiber. Seeds contain amygdalin (a cyanide precursor), so always remove them. Serving: 2–3 thin slices for small dogs, half an apple for large dogs.
• Plain pumpkin puree (not pie filling): Excellent source of soluble fiber for digestive health. One teaspoon for small dogs, one tablespoon for large dogs, mixed into food.
• Freeze-dried liver treats: Single-ingredient, high-protein, and highly palatable. Brands like Stewart Pro Freeze-Dried or Stella & Chewy's offer portion-controlled options at approximately $8–$15 per bag.

Frequently Asked Questions

This article is for informational purposes only and does not replace professional veterinary advice. Always consult your veterinarian before introducing new foods or supplements to your dog's diet, especially if your dog has pre-existing health conditions or takes prescription medications.