Can Ducks Eat Onions?

Can Ducks Eat Onions

If you’re considering getting a pet bird, ducks are your best choice. They’re large and friendly and can keep you entertained for as long as you’re in their company. These birds get attached to humans very easily and can eat a variety of both plant-based and animal-based foods. But what about onions?

Can ducks eat onions? No, Onions along with all the other vegetables from the Allium family, including garlic, are toxic to ducks due to the presence of thiosulfate in them. These compounds are not easily digestible by the birds and can cause several health issues when overfed. Spring onions, which taste better than regular onions, also contain these compounds and are, thus, equally unsafe for ducks.

In this article, we will learn all about why feeding onions to ducks is a bad idea.

Do ducks like eating onions?

Although we’re here to learn about whether or not should duck eat onions, but wouldn’t you first want to learn if your feathered pets even want to eat them?

While the main job of food is to provide nutrition to your pets, if they enjoy eating what they’re being fed, it’s always an added bonus. Most pet owners tend to spoil their pets with treats for the very same reason.

So, do ducks like eating onions? Well, the answer to it can vary according to your pet’s individual taste. Some ducks will shun onions, while others might not mind eating them as much.

As a general rule, ducks are not keen on eating onions. But if you want your pets to eat it, you can offer them these veggies and see how they take to it.


What can onions offer to ducks?

Suppose you served onions to your ducks, and they seem to like it. Will you start feeding them onions right away? No. As a concerned pet parent, it’s your responsibility to find out what these veggies have to offer to them in terms of nutrition.

In order to help you figure that out, I’ve curated a table containing the nutritional composition of onions. Take a look:

Nutrients Quantity
Vitamin A 3 IU
Vitamin B6 (Pyridoxine) 0.2 mg
Vitamin B9 (Folate) 28.5 mcg
Vitamin C 11.8 mg
Calcium, Ca 34 mg
Magnesium, Mg 15 mg
Iron, Fe 0.31 mg
Potassium, K 190 mg
Phosphorus, P 43.5 mg
Zinc, Zn 0.3 mg
Manganese, Mn 0.2 mcg
Copper, Cu 0.1 mg
Selenium, Se 0.7 mcg
Sodium, Na 5 mg
Total carbohydrates 11 g
Dietary fibers 3 g
Sugar 9 g
Protein 1 g
Calories 45 kcal

Serving Size: 100 grams

As you can see from the table, onions contain too many nutrients that can benefit your birds. They’re rich in macronutrients like protein, dietary fibers, and carbs, as well as in micronutrients like calcium, folates, pyridoxine, iron, magnesium, vitamins A and C.

In other words, onions are nutrient-dense veggies that can add significantly to your pet’s nutritional requirements. Does it mean you can start feeding them onions now? Not just yet. Before you add onion to your duck’s diet, you must go through the next section carefully.


Why are onions toxic for ducks?

If you’ve been a pet owner for long enough, you might’ve come across the warning that onions and garlic are unsafe for birds.

But have you wondered why these veggies that offer us a number of health benefits are toxic for your feathered friends? Well, wonder no more. I’m going to address exactly this question in this section.

Onions contain “Thiosulfate,” a substance that we can digest easily, but most pets, including ducks, cannot. They lack the enzymes needed to digest thiosulfate completely. That’s why, if they keep eating onions, the undigested thiosulfate will get deposited in their bodies.

Over time, the thiosulfate build-up in their body can interfere with their blood. It can cause their hemoglobin to form clumps. And since hemoglobin is carried by their red blood cells, these clumps can rupture them.

Consequently, the red blood cell count of your birds will fall severely, making the oxygen transportation in their body much more difficult for them.

The first symptom of this health issue is excess fatigue; you will notice that your ducks are growing lethargic every day, unwilling to play or engage with you. Other major symptoms of onion overconsumption include:

  • Diarrhea
  • Difficulty in breathing
  • Collapse
  • Swelling of liver and spleen

In the long run, the excess onion consumption can drop their red blood cell levels to the point where their organs cannot even function properly.

Other than this, the sulfur compounds present in onions can also harm your pet birds in other ways. When ducks munch on onions, these compounds can be harsh on the inner surface of their mouths, esophagus, and crops. Over time, it can also result in ulcers.


Are cooked onions any safer for ducks than raw ones?

All pet owners struggle with this question: should they feed their pets veggies in the raw or the cooked form? Onions are no exception to it.

Since we’ve already established that onions can be toxic to your birds, are you wondering if cooking these veggies can make them safer for your feathered pets? Unfortunately, it cannot.

Since the heat has no impact on thiosulfate, cooking onions will not make it any safer for your ducks than their raw form. In fact, cooked onions can be even more dangerous for them if you add salt or any other spice while cooking them.

To sum it up, cooked onions are in no way safer for your feathered pets than raw onions.


Are onion peels safe for ducks to eat?

It is a commonly known fact that onion peels are inedible to humans due to their unpalatable taste. But what about your ducks? Will they eat it? Well, perhaps not. Ducks will only eat onion peels out of necessity when they’re starving and have nothing else to eat.

However, if you can get your birdies to eat these peels, it can benefit their health in numerous ways:

  • Onion peels are high in vitamins A, E, and C, as well as antioxidants, flavonoids, and fibers. These are beneficial for maintaining their digestive health, boosting their immune system, and keeping their eyes and skin healthy.
  • These peels also have anti-inflammatory properties that can prevent your ducks from inflammatory diseases.


What about spring onions? Are they safe for ducks?

All of you must be familiar with spring onions, another vegetable belonging to the allium family. These veggies are close relatives of onions but have a somewhat sweeter and mellower taste.

They have long, tube-like leaves attached to their head, while the vegetable itself is significantly smaller than regular onions and come in both white and red color variations. Are these onions safe for your ducks to eat? Not really.

Much like all the other members of the Allium family, spring onions also contain thiosulfate that can prove to be fatal to their health. Therefore, they’re just as safe for your feathered pets as regular onions but will only taste better to them.


Other toxic foods that you shouldn’t feed your duck

It is no secret that pet birds enjoy sharing mealtime with their pet parents. Eating with feathered friends is a great way to socialize with them. However, there are certain foods that humans enjoy which should never be offered to pet birds due to potential toxicity.

Let’s take a look at some popular human foods that you shouldn’t feed your ducks:


Chocolates are irresistible treats for all humans, but what about ducks? Can they eat them, too?

Chocolate can be poisonous to ducks, even in tiny quantities. It contains theobromine and caffeine, both of which are toxic to them can cause vomiting and diarrhea in your pets. It can also raise their heart rate, cause hyperactivity, induce tremors and seizures, and even lead to their death.


Caffeinated beverages, such as coffee, tea, and soft drinks, are popular because they taste good and are great stimulants. We might consider offering a sip of these delectable beverages to ducks. However, even a sip or two of these beverages can be toxic to our feathered friends.

Many studies have shown that caffeine can increase their heart rate, cause arrhythmias and hyperactivity, and even end up causing cardiac arrest in ducks. So, instead of caffeinated beverages, give your thirsty bird water.


The avocado tree’s leaves contain persin, a fatty acid-like ingredient that ends up killing the fungus of the plant. This substance is also present in the fruit’s skin and pit and, if consumed by a bird, can prompt heart damage, respiratory difficulties, weakness, and even death.


Many of us add this popular ingredient to a variety of foods without even thinking about it. We also enjoy salty snacks such as chips, popcorn, pretzels, and crackers. But, just as too much salt is bad for us, it’s also bad for ducks; even a small amount of salt can be toxic to them.

Even a single salty chip or pretzel can disrupt the electrolyte and adequate fluid in a duck’s tiny body, causing excessive thirst, dehydration, kidney problems, and death.

Apple seeds and other fruit pits

Although most fruits are healthy and safe for ducks to eat in small amounts, certain fruits with seeds are not. It includes apples and pears, as well as pits from fruits and vegetables such as cherries, apricots, peaches, nectarines, and plums.

These fruits should not be fed to ducks before removing the seeds and pits, as these contain small amounts of a cardiac-toxic cyanide compound.



With this, we come to the end of our article. Today, we have learned that onions, although they’re nutrient-dense vegetables, should still not be fed to ducks. It is because they contain thiosulfate compounds, which your feathered pets cannot digest properly.