Home » Why Are Onions Bad for Parrots? (Raw And Cooked)
can onions kill birds?

Why Are Onions Bad for Parrots? (Raw And Cooked)

Last Updated on January 29, 2024 by Carrie Stephens

Red onions, spring onions, leeks, and shallots – both raw and cooked – are bad for parrots.

Onions (Allium cepa), including garlic and chives, should never be fed to parrots because they contain sulfur. This compound irritates the mouth, esophagus, or crop, leading to ulcers and anemia.

Sulfur compounds interfere with parrots’ ability to produce hemoglobin (the protein in red blood cells).

According to Bioscience, Biotechnology, and Biochemistry, the sulfur compounds in onions include:

  • Alkenylcysteine sulfoxide.
  • Diallyl sulfinate.
  • N propyl disulfide.

The plant’s tissues are activated when the onion’s tissues are compromised. When onions are peeled, sliced, chopped, or crushed, the enzymes convert to sulfur compounds.

The adverse effects of onion consumption won’t always be immediately evident. If a parrot eats a small quantity of onion, it should be medically examined by an avian veterinarian.

What Happens When A Parrot Eats Onions

Onions affect the circulatory system, but what happens when a parrot ingests onion? According to CABDirect, the parrot will develop anemia, anisocytosis, or hemolytic anemia.


Since hemoglobin is needed for healthy red blood cells, the sulfur in onions stops parrots from producing enough healthy red blood cells (anemia).

One of the initial signs of onion poisoning in parrots is lethargy, which occurs when the bird feels weak without enough healthy red blood cells.

are onions toxic to parrots?


Anisocytosis is when the red blood cells are of different sizes. In a healthy parrot, red blood cells should be about the same size.

Anisocytosis usually occurs due to untreated anemia, so it’s the natural progression of anemia.

Hemolytic Anemia

If a parrot ingests a lot of onion in one sitting or eats onion over a sustained period, it may develop hemolytic anemia. 

Hemolytic anemia occurs when the red blood cells are destroyed faster than the parrot’s body can replenish them. According to NCBI, the common symptoms include:

  • Rapid breathing.
  • Pale mucous membrane.
  • Lethargy.
  • Sitting at the bottom of the cage/avoiding flying.
  • Collapse.


Onions have acidic properties, with a pH level of 5.6. Raw onions are more acidic than cooked onions. Their acidity can cause stomach and mouth ulcers.

Onions Can Kill Parrots

Since onions cause blood disorders in parrots, eating them can be fatal. If a parrot dies from eating onions, it’s usually after ingesting them regularly or over several days.

There are many varieties of onions, so you may wonder if they’re all harmful to parrots. Unfortunately, anything in the Allium genus is dangerous.

Here are the main varieties of onions:

  • Red onions.
  • Yellow onions.
  • White Onions.
  • Green onions.
  • Spring onions.
  • Shallots.
  • Leeks.

According to UVM, yellow onions have the highest sulfur content.

Although not an “onion,” the Allium genus also includes other harmful vegetables:

  • Garlic (Allium sativum).
  • Chives (Allium schoenoprasum).

Garlic and chives should never be given to parrots because they contain sulfur-based compounds.

Toxic Parts of The Onion

All parts of the onion are toxic to parrots, so they shouldn’t be allowed to peck at onion plants or play with onion skin. They can’t be given cooked onion because it doesn’t destroy the sulfur.

As mentioned, peeling and chopping an onion releases sulfuric compounds. This means the onion is most toxic once prepared for consumption.

Even plants in the wild, like wild onion (Allium Canadensis) and pacific onion (Allium validum), are toxic.

can parrots have cooked onions?

Cooking Onions Near A Parrot

Since onions and garlic are toxic to parrots, you may wonder if cooking them for personal consumption makes them safe. Parrots’ airways are sensitive, so we should avoid creating harmful fumes.

If you cook onions and garlic at home, remove parrots from the room and close the door. Ventilate as you cook. The fumes are unlikely to cause harm, but it’s best to err on the side of caution.

Avoid cooking using Tefal cookware because the fumes can harm a parrot’s respiratory system. Problems occur when Polytetrafluoroethylene (PTFE) is heated above 536°F (280°C).

Parrots shouldn’t be near the kitchen while you cook as they’re sensitive to fumes.

What To Do If A Parrot Eats Onions

Call the veterinarian immediately for advice if a parrot accidentally eats some onion. Treatments like oxygen therapy are available, but a vet will need to examine the parrot.

Birds are slightly more resistant to the effects of onion than other species (like cats and dogs). This means a small amount of onion, on one occasion, may be tolerated.

Key Points to Remember 

  • Yellow and peeled/prepared onions are the most toxic due to their high sulfur content.
  • All onions (in any form) are dangerous and should never be given to a parrot.
  • Garlic and chives are also deadly to parrots.
  • Ventilate when cooking with ingredients (like onions and garlic), and don’t keep a parrot in the kitchen. Parrots should ideally be kept several rooms away to keep them safe.

Call the vet immediately if your parrot has ingested any onion as a precaution. If necessary, a vet can induce vomiting or perform a crop lavage (crop wash) to minimize the absorption of toxins.