Garlic Toxicity and Pets

A Small Amount Can Be Toxic

Many people consider garlic to be a holistic remedy in the prevention of heart disease, high cholesterol, high blood pressure, warding off fleas and even certain types of cancer.

These potential medicinal benefits, however, are not effective for our pets. In fact, garlic is extremely toxic to dogs and cats and the consumption of even a small amount can lead to severe poisoning and, if not treated in time, death.

Why is Garlic Toxic to Pets?

Garlic is classified as a species of the Allium family. Other species in the Allium family include onions, shallots, leeks, chives and rakkyo (otherwise known as the Chinese onion).

Unfortunately, dogs and cats cannot digest these particular plants as we can. The ingestion of Allium species in dogs and cats causes a condition called hemolytic anemia, which is characterized by the bursting of red blood cells circulating through your pet’s body.

Ingestion can also lead to gastroenteritis, also known as an inflammation of the stomach and intestines, causing stomach pain.

How Much Garlic is Toxic to Pets?

Pet Poison Helpline

“In general, garlic can be more concentrated than an onion,” says Dr. Justine Lee, a veterinary emergency critical care specialist and author of two popular books on pets. “It’s actually considered to be about 5X as potent as an onion.”

Consider the rule of thumb when it comes to onion toxicity: Consumption of as little as 5 g/kg of onions in cats or 15 to 30 g/kg in dogs has resulted in clinically important hematologic changes. According to scientific studies, onion toxicosis is consistently noted in animals that ingest more than 0.5% of their body weight in onions at one time.*

Since garlic is significantly more concentrated than an onion, an even smaller ingested amount will likely lead to toxicosis—as little as one clove of garlic can lead to toxicity in dogs and cats.

Please note that a pet’s weight, type of breed and prior health history can vary the toxicity level of ingested garlic. If you suspect your dog or cat has ingested garlic, you should contact your veterinarian immediately.

Symptoms of Garlic Toxicity in Dogs and Cats

It’s important to note that it may take up to two to four days after your pet eats garlic for symptoms to appear.

According to Lee, symptoms of garlic toxicity include breathlessness, lethargy, diarrhea, vomiting, pale gums, an elevated heart rate, an increased respiratory rate, weakness, exercise intolerance, and collapse.

Your pet also could lose interest in food as a result of this type of poisoning.

Preventing Garlic Toxicity in Pets

Garlic cloves

While mass consumption of garlic puts pets at high risk, your pet can also become poisoned after chronic ingestion of small amounts of garlic over a period of time.

So, what about pet food products that may contain garlic? Lee instructs pet owners to use a practical approach. “Remember, ingredients are listed in order of concentration in the product’s nutrition panel. If garlic appears within the first ten ingredients, we would worry.”

Pet owners who believe garlic helps prevent fleas should heed caution.

“Using garlic as a homeopathic treatment for flea prevention has been debunked as not effective,” says Lee. “I would never recommend adding any garlic powder to your pet’s meal; you could potentially injure your pet over time.”

For pet owners using garlic as a holistic remedy for their own cardiovascular issues, make sure you take steps to protect curious pets. Lee recalls treating two kittens that ingested garlic pills left within their reach. Both were treated for severe anemia.

“Pet owners often have good intentions in promoting the wellbeing of their pets,” Lee says. “Sometimes this can lead to more problems than they anticipate.”

The best advice when concerned about introducing new food or a homeopathic treatment for your pet is to always consult your family veterinarian first.

Ready for Anything

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*"Allium Species Poisoning in Dogs and Cats," R.B. Cope, BSc. BVSc, PhD