upatsix.com - Your Source For Pet Bird Information

Although most compounds have similar toxicities for a wide range of species, there are compounds that are toxic to some and not others.

An example of this is xylitol. Xylitol is a metabolic intermediate, and is constantly being produced by a minor metabolic cycle. Using it in chewing gum actually prevents tooth decay. Sometimes people use it for making cakes and other sweetened foods. HOWEVER, it is amazingly toxic to dogs, what it does is causes their blood sugar level to fall to very low levels. (I wonder if anyone has thought of using it in low doses for diabetic dogs.) Dogs have apparently died from eating pieces of cake, etc sweetened with xylitol.

Germane (germanium hydride) is another example. It is non-toxic to birds and deadly to mammals. The fumes from overheated polytetrafluoroethylene are another example--although toxic to mammals, these fumes are truly deadly to birds.

the foods we eat have generally been tested for safety to humans--but not necessarily other species.

I tend to worry a lot about mushrooms--because many mushrooms have toxins, and I have heard some claim that some that are not toxic to us are, in fact toxic to birds.

Another problems stems from the fact that smaller warm blooded animals have to eat a LOT more than larger ones to be able to keep warm relative to their weight. A 600 gram cockatoo can easily devour a 40 gram meal.

On the the other hand a 60 kg human cannot easily devour 4 kg of food!

Because small animals thus eat a lot more, toxicity levels that would be harmless to us can be fatal for them. Caffeine is an example. It is actually LESS toxic to dogs, cats, and birds than us, BUT because these smaller creatures can eat so much of it, they can get poisoned easily. (By the way it IS possible for humans to get caffeine poisoning if they really over do it!)

Avocados, by the way, seem an example similar to caffeine--the pits are quite poisonous to about any organism, but the toxicity levels in the flesh of the fruit are such that it does not harm us--but birds can easily eat enough to be poisoned.

WOW ! IT's great to have a biochemist on board... Thanks for the info !!
I also have heard of the potential problems to our feathered friends from mushrooms... carcinogenic..... Does the bioavailability of these substances vary from organism to organism?? Perhaps the toxins are unlocked differently from critter to critter giving them different levels of danger.

There are some compounds that are metabolised very differently by some creatures than others. Coumarin is an example. (found in several plants such as sweet clover and tonka beans.) The FDA for many years was concerned about it getting in the US food chain because of its demonstrated high toxicity to rats. It turns out that when rats eat it, they convert it into an highly toxic compound, whereas humans, and probably most other creatures convert it into a harmless (In fact potentially beneficial!) compound.

There are also differences within species as to metabolic paths. Different individuals can metabolise compounds differently.

It can be very dangerous to eat strange plants. Many plants contain nasty compounds to discourage hungry animals from eating them!