Would trying to boil blood that's been treated with an anticoagulant in an electric kettle break the kettle? I read here it isn't possible to boil milk in an electric kettle without a very high probability that it will break it, though someone also mentioned that there are electric kettles that can boil milk. So far so good. But what about blood that has had an anticoagulant added to it?

It's similar to milk in some ways and dissimilar in others. Would you be able to boil blood in an average kettle that has a coil inside? Would a kettle capable of boiling milk also be able to boil blood? Or is it simply not possible to boil blood with any kind of electric kettle?
The biggest issue I could see is that kettles usually aren't designed to be cleaned easily, and it would certainly need cleaning.  

I'd expect some protein residue to burn onto the element (which would then smell dreadful if left hot for long).  This may lead to overheating as in the case of milk, but it would certainly be hard to clean and taint any water boiled in it afterwards. 

For pasteurising you really wouldn't want it to boil - in fact one of the links in your comments notes that blood coagulates at lower temperatures than egg so you may have a very narrow window.  If an anticoagulant was used it would have to be not inly food safe but palatable.

In general, experimenting in the kitchen is easiest if done in easily-cleaned containers that are also easy to observe.  A kettle might be convenient but a saucepan is much more likely to be recoverable afterwards.