Many foods that are safe for us are toxic to dogs, so you have to be careful what you feed them. The leek, which is part of the allium family, causes moderate to severe gastrointestinal upset (abdominal pain, nausea, diarrhea, and vomiting), respiratory problems, and major damage to your dog’s red blood cells. Even though people may be able to enjoy the health benefits of leeks, certain proteins in your dog’s blood are unique and leeks can have a serious negative impact on their system. If you believe your dog has eaten some kind of leek, whether it is from your vegetable bin or the garden, see a veterinarian immediately, even if there are no symptoms.

The leek (Allium ampeloprasum) is a type of vegetable responsible for poisoning in dogs, similar to its relatives the onion, garlic, and chives. Even a small portion of leeks are dangerous for your dog and causes damage to the red blood cells, producing hemolytic anemia. Because of this, your dog’s bone marrow cannot work fast enough to replace the damaged blood cells and eventually will decrease the oxygen levels in the blood. Respiratory arrest and organ damage are also likely to follow, and this is fatal if treatment is not started right away.

The symptoms of leek poisoning depend on the number of leeks consumed and the size of your dog. Some of the most common symptoms are:

The leek (Allium ampeloprasum) is part of the Amaryllidaceae family in the asparagales order of the allium genus. Leeks are also a member of the onion genus that originated in Western Asia and Southern Europe. The plant became popular when cultivated in the United States and now it can be found all over the world. Leeks have flowers that are shaped like an urn and can be red, pink, or white with purple or yellow stamens. There are several types of leek which are:

The cause of leek poisoning is the organosulfate compounds which cause oxidative hemolysis. This is a life-threatening condition which is also known as hemolytic anemia and destroys the red blood cells faster than the bone marrow can make new ones. A decreased red blood cell count reduces the oxygen in the blood, causes respiratory distress, and may eventually lead to organ damage.

If you can bring a sample of the leek plant that your dog ate, this will help determine the type eaten. This is important because not all leek types have the same toxicity rate and it helps get the diagnosis more quickly. The faster the veterinarian can get a diagnosis the sooner the treatment can begin. Leeks poisoning is not difficult to diagnose, but your veterinarian will want to rule out any possible underlying disease. Be sure to provide your dog’s medical health records, recent injury or illness, and vaccination records. The veterinarian will perform a complete physical examination which will include your dog’s weight, height, body temperature, reflexes, respiration rate, blood pressure, and pulse oximetry (blood oxygen level). Laboratory tests will be done including blood glucose levels, arterial blood gas, complete blood cell count, and chemistry profile. Additionally, a urinalysis will show hemoglobin casts and the blood tests should show damage and defects in the blood cells. Abdominal x-rays, CT scan, MRI, or ultrasound can show the condition of your dog’s kidneys, spleen, and liver.

Your veterinarian will start your dog on intravenous (IV) fluids right away. Decontamination is the next step which includes encouraging your dog to vomit with a hydrogen peroxide solution, a warm water lavage (stomach flush), and administering activated charcoal to absorb the remaining toxins. Your dog may be admitted to the hospital overnight for observation and to provide supportive treatment such as oxygen therapy, blood transfusions, and medication for the anemia.

Even though leek toxicity can be serious, it is rarely lethal if your dog is healthy and if treatment is started right away. You can take your dog home once the toxins are out of your dog’s system. Iron supplements will need to be continued for about a month until you return for a follow-up blood test. Antibiotics may also be prescribed for 7 to 10 days. Do not hesitate to call your veterinarian if you have any questions or concerns.