People who aren’t aware of the risks of parrots eating avocado can be very surprised.
What is it about this fruit that people love so much, that puts it so out of bounds for birds?
Despite popular myth, dogs and cats are not considered highly susceptible to avocado poisonining (they can experience stomach upset).
But parrots are at higher risk of avocado toxicity.
Avocado plants also have very toxic effects on many mammals like rabbits, rodents, goats, horses, cows and other ruminants.
This includes the fruit, leaves (considered the most toxic part of the plant), stems, bark, seeds – all parts of the Avocado plant are toxic to birds. The avocado tree (Persea americana) is found in the plant family Lauraceae.
Branches from avocado trees should not be used as bird perches. Parrots that are housed outdoors in aviaries should not have avocado plants nearby, keeping in mind falling leaves which can blow into an aviary or outdoor enclosure.
The culprit is the compound persin, found in all parts of the avocado tree.
Persin is a fungicidal toxin. It belongs to the acetogenin family – a class of natural toxins found in some plants.
Like many plants, avocado trees have evolved defences against things that could harm or kill them; in this case, avocado trees developed persin as a natural defense mechanism to ward off fungal infections and pests in the wild.
The exact mechanism of persin toxicity in animals is still being researched, but it’s the toxicity of persin is attributed to its ability to disrupt the mitochondrial function in certain cells. This can interfere with oxygen utilization and energy production, leading to cell death and tissue damage.
While safe for humans, persin can be highly toxic to some animals – particularly birds, horses, rabbits, and ruminants like cows, goats, and sheep.
In the worst case scenario, avocado poisoning can result in myocardial necrosis – or heart attack.
There are photos out there of wild South American parrots consuming avocado, perhaps with no ill effect.
But there are many things that wild parrots do that we wouldn’t want to risk for the parrots in our care; after all, wild parrots (should, in theory given an optimal lifestyle) have stronger defences against mild or moderately harmful foods.
It’s therefore worth focusing only here on the risks of avocado consumption in captive parrots.
The highest amount of persin is actually found in the parts of the tree that we don’t consume: the leaves and bark of the avocado tree have the highest concentration of persin. Needless to say, don’t go cutting branches from avocado plants to provide as parrot enrichment.
Then there’s the large seed, or pit as it is properly named. The avocado pit holds a higher concentration of persin than the flesh but is still much lower than the leaves and bark.
Avocado skin has a lower concentration of persin compared to the pit and leaves.
But what about the actual fruit?
The edible flesh of the avocado contains the least amount of persin. That’s why most humans can eat avocado with minimal problems, although some humans do get gastrointestinal upset.
Here’s a breakdown of persin concentration from highest to lowest in different parts of the avocado tree and fruit:
- 1. Leaves and bark (most persin)
- 2. Pit
- 3. Skin
- 4. Flesh (least persin)
The concentration of persin can vary not only between different parts of the fruit, but also due to:
Ripeness: Ripe avocado pulp generally has lower persin levels compared to unripe avocados.
Avocado variety: Some avocado varieties might naturally contain higher or lower levels of persin.
The point is this: the fleshy edible part of the fruit that would be of most interest to parrots (as well as the skin) contain the least amount of the toxin persin. But that doesn’t mean it’s safe and it’s simply best to avoid giving parrots access to avocado.
Initial symptoms of avocado toxicity or persin poisoniong in birds can include one or more of these:
- an increased heart rate
- apathy and weakness
- unable to perch properly or at all
- labored or heavy breathing with noticeable tail bobbing
Internal complications that you can’t visually see, but which are a medical emergency, which occurs when a bird is affected by toxicity from persin in avocado include:
- Fluid build up around the lungs and heart
- Liver failure
- Kidney failure
Death from organ failure and heart attack (cardiac arrest) can occur within as little as 12 hours.
If you suspect your bird has accessed avocado, consult your emergency avian veterinarian immediately.
Avocado trees and avocado fruit should never be given to parrots. Birds should never have access to avocado trees or fruits.
So it’s simply common sense to not allow avocado near bird bowls, food prepration areas or utensils, nor to ever share any avocado-containing foods like guacamole, oil and pastes with parrots.
It seems counterintuitive that a fungicidal toxin like persin, beneficial for protecting avocados from fungal diseases, would be toxic to some birds.
Persin has evolved to target specific fungal enzymes and pathways that not found in all organisms.
So while it effectively disrupts crucial functions in fungi, it can cause harm in some animals. This difference in target specificity makes persin safe for some animals, like humans, while toxic to others, like birds and horses.
Then there’s the simple concept of quantity. The amount of persin ingested plays a crucial role. While small amounts might not cause any harm to a bird, larger doses can overwhelm the bird’s detoxification systems and lead to toxic effects.
This is likely because birds (and other animals) lack the enzymes needed to effectively break down persin, leading to accumulation and damage to heart tissue and other organs.
Yes, it’s a real shame that this super fruit with amazing nutritional value (think vitamin K, folate, vitamin C, potassium, vitamin E etc) is off limits to our birds. But better safe than sorry and there’s no shortage of other fantastic fruit options that are both safe and healthy for parrots.