How do we know that rust is toxic to birds?

[Finnie]

I know the commonly accepted advice is to not use rusty cages and to remove any toys once they start to rust. But I got to wondering about whether rust was truly toxic, or whether it was just something we believe because it's what we've always been told.

So I asked my friend Google about it. I was surprised to find that even though there were several items that talked about heavy metal poisoning in birds, they only pertained to lead and zinc. (Cadmium and copper and tin were also mentioned.) There was an abundance of websites where regular people just stated that rust was toxic, but there were no examples of rust ever harming any birds. And there didn't seem to be any scientific or medical literature about rust toxicity. I admit, I probably need to dig deeper, but it's easier to ask here in the meantime before I get around to doing more internet research.

Something interesting that did come up was that for wild birds, rust in the bird baths was considered to be harmless and possibly even beneficial to birds. (Nothing scientific that I could find documented about that, either, though. Just some people saying the wild birds drink rusty water from their bird baths all the time and it doesn't hurt them. Although, how do they know that for a fact?)

It seems to me, that since things in cages can rust before we notice them, then there must be ample opportunity for birds to come down with rust poisoning. So it ought to be documented somewhere. Does anybody know of any scientific facts about rust toxicity? Or are we all just believing something that is an old wive's tale?

[paul-inAZ]

Rust is iron oxide and as such is insoluble and biologically inert. To be absorbed it has to be in the form of elemental iron combined with gluconate, sulfate, etc.
In an absorbable form iron overload is possible.
Iron oxide dust has been studied and it gets hard to separate pure dust toxicity from other dusts or occupational exposures.

This reputed toxicity looks like another one of those urban myths -and there are a great many. For eg. practically all of the supplements humans buy to prevent this or that or "strengthen the immune system" have absolutely no proven value. Many are being properly studied now and proven to be worthless.

I am one of those evidence based people that searches for the data, looking for properly conducted research before accepting any of these magic potions or claims of toxicity. The "data" on those supplements is almost all anecdotal or opinions, not properly studied fact.

All that said, rust doesn't look good. Visual appeal [or lack of] is probably it's major drawback.

[chirpy]

paul-inAZ

I wanted to ask - I don't use tap water (for now I use bottled spring water until i move and get a nice filtration system so i can stop buying bottles after bottles) but for those of you who have "hard water" is it bad to give it to the birds?

[cindy]

I found this on rust...our avian vet said it is best to keep a cup or refinish the cage if rust is present. Ingestion of enough of it can lead to metal poisoning.

http://www.ehow.com/info_8616409_rusty- ... birds.html

Further reading on other metals that can be toxic http://ezinearticles.com/?Parrot-Cages- ... id=3087080

Avian Web also claims it is toxic... http://www.avianweb.com/refinishingcages.html

[Nerien]

Re the hard water:
Nope. I have hard water. All the ponds and streams and lakes in the area have hard water. (We all live on a giant lump of limestone. They used to quarry it right here. My well is drilled into limestone. It sticks out of my back hill. The ponds sit on top of it. Our water is so hard, if you slap the surface it slaps you back.) The birds are fine.

[chirpy]

Nerien LOL slap.

I see. There's so much lime deposit and whatever else in our water! The water softener is broken and his brother doesn't want to buy a new one since he's selling and we were told to move every two months by him then him canceling that idea we never could rent one. Well now that we are moving for sure whatever he says... I'm hopin to move to softer water since my daughter has very dry skin and I have eczema. I just wondered cause our water isn't "pretty" looking.. And I was scared to use it on my birds. So I guess I can use it, if I'm still scared just for their bath water cause gallons after gallons of water for my birds cat snake and us is getting a big overboard!

[cindy]

http://www.multiscope.com/hotspot/metals.htm metal poisoning

http://birdsofparadisesanctuary.blogspo ... oning.html rust is toxic

Rust is the beak down of what ever the metal is http://sugarloafanimalhospital.evetsite ... xicity.pml

[cindy]

If you google "rust heavy metal poisoning toxic to birds/parrots" a slew of sites come up and they all say the same thing rust can lead to HMP (Heavy metal poisoning) if enough is ingested.

[paul-inAZ]

Cindy:
Thanks for the links.
I'm sure you are aware that 'rust' as commonly used is iron oxide and that heavy metals are a whole 'nother thing. Heavy metals are well known to be toxic to most animals.

I could find nothing other than anecdotal support for the idea that iron oxide is toxic. Maybe it is. Can you come up with a reference to a scientific study?
thanks

[cindy]

Paul, I am going based on what I have read and the advice of my Avian Vet, which our daughter works with. I will see if she has anything in her library handy.

[cindy]

you can read up on iron overload and what it does to the body in this article.... http://drlwilson.com/articles/IRON.htm

QUOTE:
"HOW IRON DAMAGES THE BODY



1. Iron Replaces Other Vital Minerals Causing Enzyme Dysfunction. Understanding this requires knowledge of the concept of preferred minerals. It basically states that all enzymes in the body have ideally a certain mineral in each binding site that allows the enzyme to function most efficiently.

If, however, the preferred mineral is not available, the enzyme will accept a less preferred mineral in its place to allow the enzyme to function at all.

Iron replaces other vital minerals such as zinc, copper manganese, and many others in hundreds or even thousands of enzyme binding sites. This cause the enzymes to malfunction and leads to many physical and emotional symptoms.

The problem of mineral replacement is made worse by the fact that all minerals compete for absorption. Iron enjoys a selective advantage. That is, it is selectively absorbed because of its essential role in oxygen transfer. This mechanism of iron absorption definitely works against a person who is eating white flour, lots of red meat, and perhaps smokes or drinks a little alcohol, for example. Adding orange juice at breakfast makes it worse, because vitamin C enhances iron absorption greatly.

The person becomes greatly saturated with iron at the expense of other trace elements that are already deficient in the food supply.



2. Inflammation. When iron replaces other elements in the body, in addition to enzyme malfunction, the next most important problem it causes is inflammation.

This occurs because iron attracts oxygen directly to it. Then, when it contacts delicate body tissues, the singlet oxygen molecules, termed free radicals, detach and destroy body tissues. This mechanism is called oxidant damage or free radical damage, a potent cause of inflammation.

Oxidant damage contributes to many other problems as well. These include insufficient repair of the organs and tissues to meet the needs of the body. This, in turn, can cause every disorder imaginable from heart disease to cancer to hyperactive behavior.

Aging is though to be caused by oxidant damage and it may be a direct effect of iron toxicity. This is rarely diagnosed, however, unless one happens to undergo special blood tests or a liver biopsy for iron.



3. Toxic Iron Oxide. Iron oxide is formed when iron combines with several atoms of oxygen at once. It is biologically useless and quite toxic as well



4. Bacterial Growth Stimulant. Due to its properties as an excellent oxygen transporter, iron tends to stimulate the growth of common bacteria. This is a significant cause for chronic infections in our population.



5. Cellular Poison (Cancer). Imbalances related to iron reduce the output of cellular energy in the body. This leads directly to cancer, which is basically a parasite on the human body. It uses an inferior energy generating system based on direct conversion of sugar to energy without the many intermediary steps associated with the Krebs and glycolysis cycles.



Iron Synergists. Certain substances and situations favor iron accumulation and absorption. These invariably make iron poisoning worse.

For example, vitamin C and other acidic substances like tomatoes can increase iron absorption. Copper can be an iron synergist as well, although it is also an iron antagonist in the intestinal tract. This means it competes with iron for absorption in the intestines.

Copper can build up in the body to mask the presence of iron. This often occurs and is revealed on some hair tissue mineral analyses.

Other iron synergists would include white flour products for a variety of reasons other than their iron content. For example, any mineral-deficient food will enhance absorption of iron if iron is present in the diet, as it often is.

Other iron synergists are stress, anger, frustration, resentment, hostility, fear and other such negative emotions. The mechanisms for this are more complex and beyond the scope of this article. See the section on iron in the hair tissue analyses for some elaboration of this topic." End quote.

googled "analysis of iron oxide toxic to birds"

[cindy]

Googled "analysis of iron oxide toxicity"

http://www.arltma.com/Articles/IronToxDoc.htm

I did find an article by the ASPCA but would like to run it by my vet to get her take on it...let you know what she says.

[paul-inAZ]

Nice review article. Thanks.

The part you highlighted in red is pertinent. I can find no source that documents intestinal absorption of iron in it's oxide [rust] form. As far as I know it it not only 'biologically useless' but is not readily absorbed. In that there is considerable species variation in iron absorption this is something your vet may have a reference for.

[Finnie]

Cindy seems to have found a lot of the same links I did when I first Googled "rust toxicity in birds". The sources that look more credible seem to suggest that it's lead and zinc and other metals that present more of a danger. Iron included, if ingested in large amounts. But Iron and rust are not the same thing.

When I tried searching again later, I left the "birds" part out, and got rust toxicity results that pertained to humans and larger pets like dogs and cats. Some of those actually stated, like Paul did above, that when iron rusts and becomes iron oxide, it becomes inert, and therefore non-toxic. (Non-toxic being a relative term. One guy said the LD50 of iron oxide in rats was 30g/kg of body weight, which is a huge amount! Obviously, if you eat enough of anything, it can kill you.)

The veterinary results I was able to find about heavy metal poisoning involving iron were concerning ingesting an overdose of food grade iron supplements. Nothing I've found so far has linked HMP with ingestion of rust.

I think that what is happening is that most of us being non-scientific lay people are jumping to the conclusion that rust= iron= bad. And everyone under the sun who has a bird website states somewhere that your cage must not be rusty. Several of the links I clicked on were obviously copied and pasted from the same source, so that really means once source, not several.

I'm getting a little tired of sifting through all the search results that link to regular Joes on the street and people selling cleaning products. I need to find somewhere to search that references actual scientific articles.

Anyway, I'm beginning to think that it's not necessary to throw away some of my best bird toys just because they get a little rust on them while I'm washing them. Everything I've heard in the past had me paranoid that one little lick of the rust, and my birds would keel over.

[cindy]

Finnie, one of the links I found gives you a way to clean up rust, wash well afterwards...perhaps some can be salvaged. I will see if I can find it for you. They are some medical analysis on rust ingestion I sent to my avian vet to have her review. I would though still pay close attention to the heavy metal list and avoid toys and cages that could pose a problem.

I think anything/foreign material if enough is ingested in large quantities could have the potential for issues. Check out how to clean up rust. Also bear in mind our body metabolizes things differently than a bird or dog. I would err on the side of caution and either clean the toy up or toss and replace. Let you know my vet's opinion.