Cats & Onion Tops

Onion tops are toxic to cats, as are all parts of the onion. Onions are members of the allium family of bulbs, which also includes garlic, leeks, shallots, lilies and other plants. Although alliums have many health benefits for humans, including alleviation of asthma symptoms, ingestion of onion tops by cats can lead to illness and death. It is essential to keep your cat away from green onions, and to be aware of the signs of onion toxicity.

  1. Onion Toxicity

    • Onion tops cause onion toxicity in cats if ingested, which can lead to severe illness or death.

      According to veterinarian Chris Bern, cats have even died from trace amounts of onion powder in baby food. Symptoms are always present in cats that have eaten at least 0.5 percent of their body weight in onions. Onion toxicity can be caused by onion in any form, including onion tops, either consumed in a large amount once or in smaller amounts over a longer period of time.

    Heinz Body Anemia

    • Cats that eat onion tops may develop Heinz Body Anemia (HzB). The severity of symptoms depend on the amount of onion consumed. HzB is named after the Heinz Body, which is a structure created in the red blood cell due to the chemical thiosulphate in onions. Cats with HzB may eventually develop hemolytic anemia, in which the red blood cells -- which carry oxygen through the body -- burst. Cats that have ingested onion tops may develop other health problems as well.

    Signs of Toxicity

    • Cats that have eaten onion tops may begin to display symptoms of lethargy or weakness. From there, it may progress to breathlessness (since the oxygen-carrying blood cells are being destroyed), diarrhea, vomiting and a loss of interest in food. In severe cases, animals may be disoriented or partially paralyzed, or may die. Symptoms may appear two to four days after ingestion of onion tops. If you suspect your cat has consumed onion tops or has onion toxicity for any other reason, take it to a veterinarian immediately.

    Treatment

    • If onion top ingestion has occurred within the past hour, the veterinarian may induce vomiting in your cat to remove the onion from its stomach before digestion occurs. One way the veterinarian can induce vomiting is by administering a size-dependent dose of hydrogen peroxide to your cat. Other treatments include oxygen therapy, fluid therapy and blood transfusions. The best treatment for onion toxicity is prevention -- make sure your cat does not ingest even a trace amount of onion.

    Ways To Prevent Onion Toxicity

    • Keep onion tops and other alliums in places where your cat cannot get to them.

      It is necessary to keep your cat from eating any onion tops, other kinds of onions or garlic. Onion exists in trace amounts in a vast number of foods such as tomato sauce, Chinese food and baby food, so it is best to avoid giving your cat any table scraps. Also, do not leave onions on the kitchen counter or anywhere else your cat can get it.