Is Garlic Bad for Dogs?

Not only is the unique, nutty taste of garlic the basis of many delicious dishes, but it also has a range of health benefits for humans, including boosting gut health and reducing blood pressure. Wanting to share everything you love with your canine companion, you may have wondered, “Can dogs eat garlic?” 

Unfortunately, dogs cannot benefit from garlic the same way humans can. Garlic is bad for dogs, and they should under no circumstances consume garlic in any form. 

Garlic belongs to the Allium genus, which also includes other household aromatics like onions, chives, and leeks. These plants are all toxic to dogs. In particular, garlic is toxic to dogs whether it is dried, powdered, cooked, raw, or in a liquid state. If your pup ingests a large amount of garlic, they could experience life-threatening health issues such as hemolysis (the destruction of red blood cells).¹

Contact a veterinarian or animal poison control as soon as possible if your dog eats any garlic. They can work with you to determine whether the amount of garlic your dog consumed requires medical treatment. Keep reading to get the full story on garlic poisoning in dogs or use the links below to jump to a specific section. 

• What Happens If My Dog Eats Garlic?
• How Much Garlic Is Toxic To Dogs?
• Signs Of Garlic Poisoning In Dogs
• Diagnosing Garlic Toxicity In Dogs
• Treating Garlic Toxicity In Dogs
• Dogs Susceptible To Garlic Poisoning
• Is Garlic Bad for Dogs?: Frequently Asked Questions
• Final Notes

What Happens If My Dog Eats Garlic?

The toxic principles in garlic and other Allium plants are organosulfoxides. When chopped, chewed, or cooked, these organosulfoxides are converted into a mixture of sulfur-containing oxidants, which can cause oxidative damage to the red blood cells.²

Within 24 hours of ingesting garlic, oxidative damage begins, resulting in Heinz body formation and methemoglobinemia. In 3 to 5 days, hemolysis, or the destruction of red blood cells, occurs. Red blood cells carry oxygen throughout the body, so if they are destroyed, the organs that operate the body will cease to function. Hemoglobinuria, an abnormal amount of hemoglobin in the urine, may take place as a result of hemolysis as well, leading to nephrosis, a kidney disorder that causes your body to pass too much protein into the urine.¹ 

Eating garlic can threaten your dog’s health in a major way. Get them to an emergency vet clinic as soon as possible, especially if they eat a large amount of garlic. Urgent treatment can save their life. 

How Much Garlic Is Toxic To Dogs?

Even as a member of the Allium genus, garlic is considered to be particularly toxic to dogs. In fact, compared to onion, garlic is around 3 to 5 times more poisonous.¹ 

As a general rule, consuming 15 to 30 grams of garlic per kilogram of body weight is enough to cause serious hematologic changes in dogs.² A clove of garlic weighs around 3 to 7 grams, so if your dog eats one clove, they will likely not experience any serious symptoms.

However, it is important to keep in mind that certain forms of garlic are more potent than others. For example, as water is removed from dried and powdered garlic products, they contain a higher concentration of toxic principles. A teaspoon of garlic powder can have as much toxicity as 8 cloves of garlic. 

The intensity of garlic toxicity your dog experiences will depend on their size, how much garlic they consumed, what form of garlic they consumed, and even their breed and medical history. It is important to give your vet as much information as possible, so they can accurately assess the severity of the situation.³ 

Signs Of Garlic Poisoning In Dogs

The signs of garlic poisoning in dogs will vary depending on the amount eaten and how long it has been since your dog has ingested garlic. The most common and immediate signs you may notice include gastrointestinal issues, such as:

• Decreased appetite
• Abdominal pain
• Vomiting
• Diarrhea
• Excess salivation⁴

More serious clinical signs will likely not manifest until the sulfur-containing oxidants of garlic have already caused hemolysis, which typically occurs after 3 to 5 days. If your dog has eaten a large enough amount of garlic, however, you may also start to notice these signs occurring after one day. They include:

• Depression: Your dog may not seem as peppy and energetic as usual. They may not be interested in activities that typically excite them, such as playing and going for walks.
• Weakness: It may be hard for your dog to get up from a resting position. They may even shiver or have a wobbly gait. 
• Exercise intolerance: Even if your dog wishes to partake in physical activity, they will easily overexert themselves. They may collapse in the middle of exercise. 
• Pale mucous membranes: Pale mucous membranes indicate that there is not enough oxygen being delivered throughout the body, especially to the tissues.
• Rapid breathing: Your dog may be breathing abnormally fast and deep breaths, and their mouth may be partially open. 
• Rapid heart rate: In most dogs, a heart rate greater than 160 beats per minute (bpm) is considered faster than normal. This number is 140 for giant dogs, 180 for toy dogs, and 220 for puppies. 
• Jaundice: Dogs with jaundice will have excessive yellow pigment in their blood and tissues. Jaundice is most discernible by looking at the eyes and gums.   
• Blood in the urine: Blood in the urine is a sign of hemoglobinuria. The color of your dog’s urine may range from red to brown.¹

Diagnosing Garlic Toxicity In Dogs

If you suspect that your dog has eaten a large amount of garlic, it is best to take them directly to an emergency veterinarian. Veterinarians will typically diagnose garlic toxicity based on three aspects. They are:

1. Patient history of exposure: It is important to give your vet as much information as possible to help them pin down the severity of the garlic toxicity your dog is experiencing. When did your dog eat garlic? How much garlic did your dog eat? What type of garlic did your dog eat? How have they been behaving at home or on the way to the hospital?⁵ 
2. Clinical signs: Your vet may observe certain clinical signs or conduct a series of tests, such as bloodwork to assess the function of your dog’s kidneys or urinalysis to determine hemoglobinuria.¹ 
3. The confirmation of a Heinz body-type hemolytic anemia: Hemolytic anemia results from the loss of red blood cells. Bloodwork is required to evaluate changes in red blood cell count.¹ 

Treating Garlic Toxicity In Dogs

When treating garlic toxicity in dogs, the more life-threatening clinical signs will be taken care of first. In severely affected dogs, veterinarians will provide supplemental oxygen and administer blood transfusions as needed.¹ IV fluid therapy may also be conducted to protect their kidneys from hemoglobinuric nephrosis. IV crystalloids may also be used to combat extensive vomiting and diarrhea or if there are clear cases of hemoglobinuria and hypotension.⁵

As there is no specific antidote for garlic poisoning in dogs, in less affected dogs or dogs that have yet to reach hemolysis, veterinarians will mostly focus on decontaminating the gastrointestinal tract and removing the garlic from their body. They may induce vomiting in dogs that have ingested garlic within the past two hours if they are asymptomatic and stable, administering activated charcoal after they vomit. The charcoal is used to absorb the remaining toxins in the gastrointestinal tract.⁵ 

Dogs Susceptible To Garlic Poisoning

Factors that induce red blood cell (particularly erythrocyte) oxidative injury or decrease red blood cell oxidative defenses may increase a dog’s susceptibility to garlic poisoning. This includes dietary factors, concurrent treatment with xenobiotics, inborn errors in metabolism, and  nutritional deficiencies, such as zinc deficiency.² 

Certain dog breeds have inherited high erythrocyte reduced glutathione and potassium concentrations and are more susceptible to Allium-related oxidative damage. This is a trait common in Japanese dog breeds, such as Shibas and Akitas.⁵

Is Garlic Bad for Dogs?: Frequently Asked Questions

Can I feed my dog garlic supplements?

Garlic is bad for dogs. You should never feed your dog anything that contains garlic as it could seriously impact their health. While garlic supplements have a variety of benefits for humans, there is no research that supports it having positive health effects on dogs.

Can I feed my dog garlic bread?

Do not feed your dog garlic bread. Ingesting garlic can cause oxidative damage to your dog’s red blood cells, resulting in a lack of oxygen in their body. Garlic bread is particularly oily and causes pancreatitis. If the garlic bread uses garlic powder, your dog may be at even more risk. Garlic powder is much more potent than regular garlic, with one teaspoon equating to 8 cloves of garlic. 

How long does garlic poisoning last in dogs?

Depending on the amount of garlic ingested, the poisoning could develop anywhere from 1 to 5 days after ingestion. While gastrointestinal signs may manifest almost immediately, depending on the amount of garlic your dog has ingested, the more serious symptoms of garlic poisoning may not begin to show until 3 to 5 days after ingestion. If you know your dog has eaten a bit of garlic, consult a vet or Animal Poison Control on whether you need to take them in for a checkup. If you begin to notice signs of garlic poisoning, rush them to the vet as soon as possible. The sooner you get your dog veterinary help, the sooner they can start to get better. 

Final Notes

There are many foods healthy for humans that dogs cannot consume, including garlic, onion, grapes, and avocados. Always consult a veterinarian if you want to share any of your human food with your pup. As pet parents, we want our pets to live long and healthy lives, and it is our responsibility to safeguard their wellbeing.

If you need immediate information or an accurate diagnosis when your regular vet is unavailable, Dutch can connect you with licensed U.S. veterinarians from the comfort of your own home. Get started with Dutch today.