Avocado toast is the darling dish of Millennials, especially those interested in eating a plant-based diet. I suspect it became a global phenomenon because it combines health benefits and ease of preparation into a tasty meal. Spread on whole-grain bread, avocado provides fiber, vitamin E for healthy skin and hair, lutein for eye health and healthy fats that may help lower cholesterol.

If avocados are so good for people, are they good for pets? The short answer: it depends very much on the species, and for some animals the answer is a definite no. I’ll explain why in today’s blogpost.

A Rabbit Hospitalized After Eating Avocado Peel

I decided to investigate avocado and pets after noticing an unusual emergency admission to the Schwarzman Animal Medical Center’s Zoological & Companion Exotic Pet Medicine Service. The patient was a Holland Lop rabbit admitted for avocado ingestion. Seeing that, I jumped to the Pet Poison Helpline to read about avocado toxicity.

I found that avocados contain persin, a toxin found in the fruit, leaves, stems and seeds. In sensitive species, persin can cause fluid around the heart and lungs, as well as inflammation of the heart muscle. In the ER, this avocado-munching bunny was given activated charcoal in hopes of binding up the persin and then admitted to the hospital for ICU monitoring and a cardiology evaluation.

How Avocado Can Affect a Rabbit’s Heart

The next day, evaluation by AMC’s Cardiology Service identified changes consistent with heart inflammation: fluid had accumulated around the rabbit’s heart, and the blood level of troponin was elevated, indicating heart muscle injury. By the next day, the fluid around the heart had decreased. More than just the foot of this rabbit was lucky; this was one lucky rabbit.

Which Animals Are Sensitive to Avocado?

As it turns out, rabbits are not the only animals sensitive to persin. Avocado can also sicken birds, horses, sheep, goats and cattle. The only good thing I see about the list of species made ill by avocados is that there will be more avocados for those of us who like to eat them.

Are Avocados Safe for Dogs and Cats?

Dogs and cats are less susceptible to the toxic effects of persin than rabbits, birds and livestock, but that doesn’t mean an avocado belongs on their menu. If swallowed, an avocado pit can be just the right size to get lodged in the stomach or intestine, causing vomiting and potentially an obstruction.

As I was writing this blog, someone told me about their cat that developed an intestinal obstruction from the little piece of stem on the top of an avocado! While a tiny taste of plain avocado flesh is unlikely to be the calamity it could be for a rabbit or bird, keep pits, peels and stems in a tightly closed compost bin.

This story is a serious reminder that what is good for you may not be good for your pet. Before feeding your pet something new, check with your veterinarian. And if your pet eats avocado—or anything else they shouldn’t—be prepared to call your veterinarian, a pet poison hotline or make a trip to the animal ER.