So I cleaned up a rusty zwickey broadhead tonight and its pretty well cleaned up but I have a question.  Let's say I did shoot a rusty broadhead could that contaminate the meat and make it unfit to consume and make me sick.. If so how much rust is the threshold and will a few spots of rust cause bad effects. Tetanus scares me and I know it comes from rust.

if you are concerned then don't risk it. however, I would think that tetanus is blood borne and would need to be actually in the blood stream of the animal while its heart is still pumping blood through its body. Unless you are planning on eating the lungs, where you should place the shot, I wouldn't give it a thought, but that is me, you have to make yourself comfy with it.

You are worrying too much.  Get em clean enough for you and shoot a deer.  
ChuckC

Yeah I agree . I was just wondering if anyone has ever heard of anything like that or has more information.  Just something ive wondered from time to time and it came up again so I had to ask

There are bacteria everywhere.  Much of the outermost layer of your skin is composed of bacteria living on you.  

The gut contents of any animal, including deer are just full of organisms, some of them nasty ones.  

The environment is full of organisms and we gut out a deer, drag it to the vehicle  (thru the muck) and in some cases put it on top of the car, where all the windborne dirt and microbial organisms can get on it.

There are a lot of things that I personally would worry much more about than a rusty (even a REALLY rusty) broadhead contaminating my venison.

I'm thinking that you should relax and enjoy your venison.  You've earned it.
ChuckC

I would be worried about not being sharp enough because of the rust.

There's more iron in a loaf of bread than you would transfer to the meat and you need iron in your diet anyways! I worry more about lead in an animal shot with a firearm and that hasn't hurt me yet that I know of!

You may be experiencing OCD if your are developing and obsession and severe anxiety regarding rust on your broadhead contaminating (which is a common obsession) meat and you can only very temporarily be alleviated of the anxiety of you compulsively polish, wash and sanitize your broadheads.  When you cannot control this cycle, you have OCD.

Rust on a broadhead is a non-issue as long as it is sharp. Go hunting!

Just think how many deer have scratched their arse jumping rusty barbed wire fences, lol! If you're determined to obsess, then worry about how many years it's going to take scientists to find the link between BSE (mad cow), CWD (chronic wasting) and all the variants of CJD (Creutzfeldt-Jakob) in humans.  At my age, I sleep well (i.e. don't worry about jack....)!

  Ever hit one in the guts?

Tetanus is caused by toxins from the unbelievably common bacteria Clostridium tetani. This bacteria is everywhere, and so are the spores that begin the infection. However, in order for the toxic conditions to appear, the bacteria must be exposed to the perfect conditions....same thing with botulism.

Basically the spores must be on an object (like a rusty nail from the ground) and that object must penetrate deep into tissue....where under low oxygen conditions, the spores can germinate and produce the toxin.

If you kill the deer, it will not be alive long enough for the spores to do anything...but if you wound it, you could be infecting that animal with the spores. Also, if you cut yourself with the broadhead...are a stick, or get a bug bite even...there's always a chance, every single day, that you could get infected too.

Get a tetanus shot. Problem solved.          

Don't confuse the issue though.  Rust is not necessary for the organism to grow.  It is just a descriptor. Clostridium organisms are generally anaerobic, as alluded to above.  That means that they need an environment that is without, or very low in oxygen to flourish. They form spores as a way to weather bad conditions, and spores are all over and can stay around for.. years, maybe centuries.

A deep wound, especially a puncture that closes up might supply such conditions.

Generally, they are poor competers in the general population and quicker growing everything else often crowds them out, kinda like weeds in your grass ( or vice versa).

There are a BUNCH of other organisms that are much more prevalent that would be much more of a worry to you every single day.

ChuckC

Touch up your BH and coat in in a thin layer of Vaseline. Really reduces the rust. I shoot Zwickeys also and in my opinion it is a requirement on my BH.

rust doesn't cause tetanus....a bacteria does.

The old rusty nail through the foot causes tetanus is from rusty nails on home farms and such.

The bacteria that causes tetanus can live in soil and manure.
A rusty nail can harbor dirt and manure that possibly hold the bacteria in the rough surface caused by the rust.

...a new smooth nail on the other hand can't hold as much "stuff" cause it's smooth.

Good input and spot on to the original posters exact question.

Since it's been answered, might I pose another question that seemed like the elephant in the living room?

Why would you hunt with a rusty broadhead?  Rust forms microscopic pits in the cutting edge, doesn't it?

We all speak about "scary sharp" heads to do the most damage.  Why would you not work to remove ALL the rust to ensure a super sharp head?

If there is deep pitting, then you might not get it all, but I have to suppose that might be the basis of the poster's concern? Deep Pitting?

I've sharpened blades on knives and BH's that were badly pitted and while I can't get all the pitting out, I sure did on the cutting edge.  Otherwise, that head is retired.  

There has been excellent data provided to make the poster rest easy on the contamination aspect of a rusty anything causing tetanus infection, so I hope I'm not being insulting by focusing on the issue of a very clean, super sharp cutting edge to boot!      

I'll try to find the video... I think Nugent was talking about his old broadhead collection,and remarked about how Fred Bear would sharpen his arrows, and then dull them slightly, and removed the bleeders.

I think the jist was a surgical edge, made a surgical wound that is more likely to close and not bleed. Whereas a rougher cut bleeds more. (I'm sure many have experienced this ourselves).

Found it...

Last 4min are the meat of it.

  Nugent video link

These are amazing answers and I never thought it would take off this much !! Thanks for the input I am definitely resting easier now   . That nugent video is cool.