I think there are generally other factors in supporting legislation than just whether I would do something myself. I may not smoke, but may not favor legislation banning smoking outright, etc.

But we aren't talking about something I would do myself. We're talking about my moral and political stance on an issue, which has very strong implications regarding what legislation might be supported.

Factors such as cost of executing the law, whether a law can be written in a sufficient way to deal with all the relevant factors clearly enough to sufficiently mitigate litigiousness, unintended consequences (e.g. laws requiring hospital admitting privileges may be justifiable on their face, but can end up closing clinics and increasing overall mortality), and the laws effectiveness (abortion laws may not actually reduce the number of abortions, but instead make them less safe), etc.

I am aware, which is why I've taken the stance that I would support legislation under these conditions. A lot of my misgivings have to do with interpretation of the law, hence why I have not thus far attempted to present suggested wording for a bill to this effect.

if different animals have different rights, then assigning the fetus "animal rights" becomes a bit less meaningful - is there a specific animal we should be using that provides the closest approximation?

Different animals don't have different rights. When I referred to 'relative rights of various animals' that is referring more to circumstances like your goldfish situation. As I noted, I wouldn't favor getting rid of either animal, but were that option off the table, my call would be to get rid of the cat. I don't believe further exploring this angle is beneficial to this discussion, hence my attempt at dismissal.

I gave it as one example of a difference used to justify rights, not as the only reason used. In your might-makes-right example, favoring the cat could still be justified.

I disagree, because it's not a might-makes-right scenario across the board. It's might-makes-right in a sense, as humans have the ability to control other animals to the extent of having the ability to define our rights and elevate ours above theirs; no animal appears to have the capacity to understand such a concept as rights, even the most intelligent non-humans we know, and none can really challenge humans. From our position of power, we assign ourselves 'human rights' and assign 'lower' animals 'animal rights.' I don't believe assigning a cat more rights than a fish is at all reasonable, personally.

If animals don't have a right not to be eaten, do fetuses?

In the face of a predator capable of such, I don't believe so. There are certainly no laws against animals eating fetuses. here are laws against humans eating human flesh, wish fetuses would fall under, so it wouldn't be acceptable for humans to eat fetuses should they be so inclined. We ourselves are known to eat some fetal animals (like balut).

does inadvertently stumbling into one in the desert/woods = provocation?

I believe you're misreading me here and conflating my position somewhat. I believe that it is acceptable to kill an attacking animal even if it was an accidentally provoked attack, out of self defense. I do not believe that it is acceptable to seek out an animal that attacked under provocation and put it down after the fact. I believe it is acceptable to do so with an animal that has formed a habit for attacking without provocation. I just thought it important to clarify here, as it really seems like you're getting my stance on self-defense mixed up with my stance on preventive euthanasia.

Rarity is here again being used to avoid the issue. It is either moral in your view or it isn't. Rarity might impact the way legislation is written but even then outliers should at least be considered.

It's not being used to avoid the issue; you don't get to shoehorn my moral view into 'it's always good or it's always bad.' I am completely allowed to be conditional here. It can only be perceived as a dodge if you're looking for a law on the matter, and from the legal perspective, I would legislate on the common issue rather than the rare issue, unless appropriate limitations can be devised to allow for the rare one.

If someone in the forest stumbles upon a fox that appears to be acting weird and is progressing towards them, could they morally kill it?

Should there be a law against killing it?

I'd toss a couple stones at it first. If it didn't run off from that, I'd say go for it. Foxes are pretty skittish, although they CAN get used to humans. A tossed stone will scare off even the biggest fox though, unless it's rabid.

No law in this case.

If someone is bitten by an animal outside of town and they think it has rabies (and is able to capture it), can they morally/legally have it tested since it would kill the animal for a less than lethal act?

Legally, sure. Morally, I would need more info as to why they believe it to have rabies to make the call.

Right, I figure this might be more akin to the cat/goldfish thing. E.g. one pet poses a threat to the other, etc.

Fair enough; I believe I responded to this already at any rate.

It is regarding the rights of the fetus, I assume that is whether it is vis-a-vis the mother or another fetus.

I can understand it appearing to be that way to you, but remember the overall debate is concerning what rights, if any, fetuses have. Regardless of what rights they do or do not have, fetus' have equal rights, so 'rights' wouldn't be a factor in answering your fetus vs fetus questions, only the situation. Mother vs. fetus is far more relevant.

I was aiming more for the case where both have severe issues - e.g. severe deformation of the fetus combined with near certain likelihood of permanent organ damage for the mother if she continues the pregnancy

In the generally unlikely event that such circumstances become apparent after 12 weeks (most complications become evident well before then, though certainly not all), I would probably support abortion under these circumstances, though I believe the nature of the deformation, which organ was to be damaged permanently, and the extent of the damage should be considered. I mean, if the severe deformation in question was dwarfism, and the mother was going to suffer a permanent 50% reduction in the function of one of her kidneys, I'd oppose abortion. I expect, though, that I'd support abortion in most cases under this category.

I agree that this is a major factor in constructing relevant legislation, but I would caution that words like "actual threats", "severe", "life-threatening", etc are also vague. Shouldn't the law include "the methodology used to generate those chances" as well?

See way above; I am not attempting to draft legislation here, just communicate ideas. I also believe that legislating the methodology involved is a mistake, as it ultimately amounts to voters and politicians telling doctors how to do their job. They already do this generally speaking, but dictating guidelines like this? I don't like the idea of every doctor having to use the exact same methodology- it would seem to remove a lot of quality from the equation, and devalue the possibility of getting a second opinion. I believe medicine to be over-regulated as it is...

If an actual pregnant woman is told by her doctor (after 12 weeks) that she has a complication with her pregnancy and has only a 50/50 chance of surviving if she were to attempt to have the child - should that qualify legally as life-threatening?

Not enough information to answer the question. I need to know the following:

1) When you say 50/50 chance of surviving if she were to attempt to have the child, I'm assuming that means natural delivery carried to term, correct?

1) What are her chances of survival if the fetus is aborted immediately?

2) What are her chances of survival if the fetus is carried to term but delivered via c-section?

3) How far along is the mother when the complication is discovered?

4) What are her chances of survival if the fetus is carried to 24-weeks gestation (viability) and delivered via c-section?

Thank you. You are very smart and I respect you. You want to continue? :)